Method of producing co-precipitate, co-precipitate and use thereof

Abstract

The present invention relates particularly to a method for producing a coprecipitate comprising nickel, manganese, and / or cobalt, and the coprecipitate produced by the method. The method may be a method for producing a coprecipitate comprising at least two metals selected from nickel, cobalt, and manganese, and the method comprises: (i) providing an aqueous feed solution comprising the at least two metals and at least one impurity; and (ii) adjusting the pH of the feed solution to between about 6.2 and about 11 to provide: (a) a coprecipitate comprising the at least two metals; and (b) a supernatant comprising the at least one impurity.

Description

Technical Field

[0001] In one embodiment, the invention relates to a method for producing a coprecipitate comprising nickel, manganese, and / or cobalt, and the coprecipitate produced by the method. In another embodiment, the invention relates to a method for dissolving a mixture of metals for subsequent production of a coprecipitate. Prior Technology

[0002] It should be fully understood that any reference to prior art disclosures herein does not constitute an acknowledgment that such disclosures constitute part of the general common knowledge in the art in Australia or any other country.

[0003] Lithium-ion battery packs account for a large proportion of global portable battery pack sales, and more generally, battery pack sales. Their high energy density, long lifespan, and light weight often make them the preferred battery pack for various applications, including electric vehicles, electric bicycles and other electric power devices, and power tools. A particularly common combination of active materials in these battery packs is nickel-manganese-cobalt, also known as NMC (or NCM) material. Different proportions of nickel, manganese, and cobalt are used in different types of lithium-ion battery packs. Battery packs may also use only one of these elements, or any combination of two of these three elements, or one, two, or three of these elements combined with one or more additional elements such as aluminum and magnesium. Different proportions of all these elements are used in different types of lithium-ion battery packs.

[0004] NMC materials used in battery packs are typically produced by dissolving individual, high-purity salts of nickel, cobalt, and manganese in a solution at specific ratios and purities. A precipitation process is then performed on this solution, causing the three metals to co-precipitate as hydroxides, carbonates, or hydroxycarbonates. This is widely considered the only way to achieve the high-purity precursor product composition required for acceptable electrochemical performance. However, a drawback of this process is the need to remove impurity elements from the nickel, cobalt, and manganese feedstocks to ensure their use in the production of battery pack materials. For example, NMC materials may require a purity level of approximately 150,000 moles of NMC compared to 1 mole of impurity elements. An example of nickel sulfate used in battery packs has impurities such as 5 ppm or less, including copper, iron, cadmium, zinc, and lead. Therefore, multiple separation and purification steps are required to produce pure salts of nickel, cobalt, and manganese, which can be time- and material-intensive (and therefore costly).

[0005] The natural nickel:cobalt ratio in nickel deposits typically ranges from 10:1 to 100:1, and therefore, the relative proportions of nickel, cobalt, and manganese in such deposits usually need to be modified before they can be used to produce NMC materials. Nickel deposits also typically include a range of other minerals, including, for example, iron, magnesium, and silicate minerals, and therefore require extensive processing before they can be used to produce NMC materials.

[0006] Another potential source of nickel, cobalt, and manganese is spent lithium-ion battery packs. From both an economic and environmental perspective, the disposal of lithium-ion battery packs is receiving increasing attention as the battery pack market expands. Environmentally, spent battery packs contain high concentrations of metals such as nickel, cobalt, and manganese, as well as volatile fluorinated electrolytes. With the increasing demand for lithium-ion battery packs and the strong push for material recycling, there is a growing need to find better methods to recover NMC material with sufficient purity from the cathode active material (CAM or black lumps) of spent lithium-ion battery packs, enabling its recycling for use in new lithium-ion battery packs.

[0007] Lithium-ion battery packs typically have five main components: casing, electrolyte, separator, anode, and cathode. The casing, usually made of steel, houses all other components and is relatively inexpensive. The electrolyte carries the charge within the pack and is composed of a lithium-containing salt (typically lithium hexafluorophosphate or lithium tetrafluoroborate) dissolved in an aprotic organic solvent. The separator, usually a polymer membrane, separates the anode and cathode half-cells of the pack. Lithium-ion battery packs typically have a graphite anode connected to a copper current collector. The majority of the pack's value comes from the cathode. Modern lithium-ion battery packs have cathodes coated with electrochemically active lithium compounds containing cobalt oxide or a mixture of nickel, cobalt, and manganese (NMC). This cathode material is typically mixed with graphite and bonded to an aluminum current collector using an adhesive.

[0008] Various conditions have been tested to recover NMC materials from cathode active materials, but recovering nickel, cobalt, and manganese without recovering large amounts of unwanted impurities remains a challenge. To date, efforts to recycle large quantities of NMC materials have aimed to produce individual salts of nickel, cobalt, and manganese for further use or highly purified solutions for further applications.

[0009] Some battery pack applications may also require the use of materials that contain only two of nickel, cobalt, and manganese, and the above considerations will also apply to such materials. Summary of the Invention

[0010] In one embodiment, the present invention seeks to provide a method for producing a coprecipitate comprising at least two of nickel, manganese, and cobalt, which at least partially addresses or substantially improves at least one of the aforementioned disadvantages or provides a useful or commercial option for consumers. This coprecipitate is suitable for the preparation of lithium-ion battery packs. In another embodiment, the present invention seeks to provide a precipitate for the preparation of a precursor for lithium-ion battery packs, such as a precipitate comprising one, two, or all three of nickel, manganese, and cobalt, suitable for subsequent preparation of NMC materials (especially cathode active NMC materials) or materials comprising at least two of nickel, manganese, and cobalt (especially cathode active materials). In yet another embodiment, the present invention seeks to provide a method for producing a solution that (potentially after further processing) is suitable for producing a coprecipitate comprising nickel, manganese, and cobalt, or that solution at least partially addresses or substantially improves at least one of the aforementioned disadvantages or provides a useful or commercial option for consumers.

[0011] According to a first aspect of the present invention, a method for producing a coprecipitate comprising at least two metals selected from nickel, cobalt, and manganese is provided, the method comprising: [(i)] Provide an aqueous feed solution containing at least two of the metals; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, so that at least two metals are co-precipitated in the feed solution.

[0012] The following options and embodiments may be used individually or in any suitable combination with the first state.

[0013] Aqueous feed may contain at least one impurity. Therefore, the step of adjusting the pH of the feed solution can provide a supernatant containing the at least one impurity. Therefore, in one embodiment of the first state sample, a method for generating a coprecipitate is provided, wherein the coprecipitate comprises at least two metals selected from nickel, cobalt, and manganese, the method comprising: [(i)] Provide an aqueous feed solution containing at least two of the metals and at least one impurity; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, in order to provide: (a) a coprecipitate containing at least two of the metals; and (b) a supernatant containing at least one of the impurities.

[0014] In one embodiment, the method is a method for producing a coprecipitate, wherein the coprecipitate comprises at least two metals selected from nickel, cobalt, and manganese, and the method includes: [(i)] Provide an aqueous feed solution comprising at least two of the metals and at least one impurity, wherein the at least one impurity is selected from the group consisting of: arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, vanadium, lanthanum, lanthanides, actinium, actinides, titanium, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium and niobium, or combinations thereof; and [(ii)] Adjust the pH of the feed solution to between approximately 6.2 and less than 10 in order to provide: (a) a coprecipitate containing at least two of the metals; and (b) a supernatant containing at least one of the impurities.

[0015] In one embodiment, the pH of the feed solution is adjusted to between approximately 6.2 and 11, or between approximately 6.2 and 11, or between approximately 6.2 and 10, or between approximately 6.2 and 10, or between approximately 6.2 and 9.2, or between approximately 6.2 and 8.5, or between approximately 6.2 and 7.5.

[0016] In one embodiment, the total amount of at least two metals (or the total amount of nickel, cobalt, and manganese) in the aqueous solution is less than 95% of the total weight of the aqueous solution (especially the dry solids in the aqueous solution), particularly less than 90%, or less than 85%, or less than 80%, or less than 75%, or less than 70%, or less than 65%, or less than 60%, or less than 55%, or less than 50%. In one embodiment, the total amount of metal complexes containing at least two metals in the aqueous solution (or the total amount of metal complexes containing nickel, cobalt, and manganese) is less than 95% of the total weight of the dry solids in the aqueous solution, particularly less than 90%, or less than 85%, or less than 80%, or less than 75%, or less than 70%, or less than 65%, or less than 60%, or less than 55%, or less than 50%. As used herein, the term "metal complex" may include, for example, sulfates of nickel, cobalt, or manganese. In one embodiment, the total amount of at least two metals (or the total amount of nickel, cobalt and manganese) in the aqueous solution exceeds 1 ppb, particularly exceeding 1 ppm, or exceeding 10 ppm, or exceeding 100 ppm, or exceeding 1,000 ppm, or exceeding 2,000 ppm, or exceeding 5,000 ppm, or exceeding 10,000 ppm, or exceeding 20,000 ppm or exceeding 50,000 ppm.

[0017] In this specification, references to "metal" or a particular metal (such as nickel, cobalt, or manganese) do not necessarily imply that it is in a metallic form (i.e., oxidation state 0). Unless the context otherwise indicates, such references include all possible oxidation states of a metal, including metal salts.

[0018] As used herein, "at least one impurity" (which may be "at least one precipitated impurity") is not nickel, cobalt, manganese, water, OH-, H+, H3O+, sulfate, or carbonate. However, in one embodiment, the at least one impurity is not a nickel, cobalt, or manganese complex having an anion (such as sulfate, carbonate, or hydroxycarbonate). In one embodiment, the at least one impurity is selected from the group consisting of: arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, vanadium, lanthanum, ammonium, sulfite, fluorine, fluoride, chloride, titanium, scandium, iron, zinc, and zirconium, or combinations thereof. In one embodiment, the at least one impurity is selected from the group consisting of: arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, vanadium, lanthanum, lanthanides, actinium, actinides, titanium, ammonium, sulfite, fluorine, fluoride, chloride, scandium, iron, zinc, zirconium, silver, tungsten, vanadium, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, lead, niobium, or combinations thereof; particularly arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, vanadium, lanthanides, actinium, actinides, titanium, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, and niobium, or combinations thereof. In one embodiment, the at least one impurity comprises or is: (i) calcium and / or magnesium; (ii) alkaline earth metals; (iii) metal or metalloid species (excluding alkali metals); (iv) metal or metalloid species that do not include alkali metals or anionic species (such as sulfates, sulfites, chlorides, fluorides, nitrates and phosphates); or (v) metal or metalloid species that do not include anionic species (such as sulfates, sulfites, chlorides, fluorides, nitrates and phosphates).

[0019] In one embodiment, the at least one impurity may be at least two impurities, at least three impurities, at least four impurities, at least five impurities, or at least six impurities. Such impurities may be as described in this specification.

[0020] In one embodiment, in the aqueous feed solution of step (i) or step (ii), 1% of the at least one impurity, or at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50% of the at least one impurity, particularly at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 96%, or at least 97%, or at least 98%, or at least 99% of the at least one impurity, may be the supernatant after co-precipitation, or the washing solution after washing the coprecipitate, or a combination of both supernatant and washing solution. At least one impurity may be a combination of impurities. The amount of each impurity in the aqueous feed solution that can be transferred to the supernatant may vary for each impurity.

[0021] In one embodiment, the molar ratio (or mass ratio) of at least two metals to at least one impurity (or at least one precipitated impurity) in the aqueous feed solution (or the molar ratio (or mass ratio) of at least two metals to total impurities in the aqueous feed solution) is less than 300,000,000:1, or less than 200,000,000:1, or less than 100,000,000:1, or less than 1,000,000:1, or less than... The ratio is 500,000:1, or less than 250,000:1, or less than 200,000:1, or less than 100,000:1, or less than 50,000:1, or less than 10,000:1, or less than 5,000:1, or less than 1,000:1, or less than 500:1, or less than 200:1, or less than 100:1, or less than 50:1, or less than 25:1, or less than 10:1, or less than 1:1 or less than 1:10. The mole ratio (or mass ratio) of at least two metals to at least one impurity in the aqueous feed solution (or the mole ratio (or mass ratio) of at least two metals to total impurities in the aqueous feed solution) may be at least about 2,000,000:1, or at least about 1,000,000:1, or at least about 100,000:1, or at least about 60,000:1, or at least about 30,000:1, or at least about 20,000:1, or at least about 10,000:1, or at least about 5,000:1, or at least about 1,000:1, or at least about 500:1, or at least about 200:1, or at least about 100:1, or at least about 50:1 or at least about 10:1. This refers to the sum of the molar amounts (or masses) of at least two metals, but may refer to any one of at least one impurity or the sum of the molar amounts (or masses) of all such impurities. At least one, or more than one, possibly all impurities may be selected from the group consisting of calcium, magnesium, lithium, sodium, potassium, and ammonium. In one embodiment, at least one impurity in the aqueous feed is selected from the group consisting of: calcium, magnesium, iron, aluminum, copper, zinc, lead, sulfur, sodium, potassium, ammonium, and lithium.

[0022] It should be understood that unless the context indicates otherwise, reference to a metal herein does not imply that the metal is in an oxidation state of 0. For example, depending on the context, reference to nickel may refer to any or all of Ni(0), Ni(II), and Ni(III). In one embodiment, at least two metals selected from nickel, cobalt, and manganese are nickel, cobalt, and manganese. Nickel, cobalt, and manganese may be in any suitable oxidation state. In one embodiment, at least two metals are selected from Ni(II), Co(II), and Mn(II).

[0023] In some embodiments, the pH of the feed solution in step (i) may be less than 7.0, or less than 6.75, or less than 6.5, or less than 6.25, or less than 6.2, or less than 6.0, or less than 5.75, 5.50, 5.25, 5.0, 4.75, 4.50, 4.25, 4.0, 3.75, 3.50, 3.25, 3.0, 2.75, 2.50, or 2.0. The pH of the feed solution in step (i) may be greater than 2.0, or greater than 2.25, 2.50, 2.75, 3.0, 3.25, 3.50, 3.75, 4.0, 4.25, 4.50, 4.75, 5.0, 5.25, 5.50, 5.75, 6.0, or 6.2. In some embodiments, the pH of the feed solution in step (i) may be 1.0 to 4.0, 2.0 to 4.0, 4.0 to 6.0, 2.0 to 3.0, 3.0 to 4.0, 4.0 to 5.0, or 5.0 to 6.0, or 6.0 to 7.0. In some embodiments, the pH of the feed solution in step (i) may be 1.0 to 1.5, 1.5 to 2.0, 2.0 to 2.5, 2.5 to 3.0, 3.0 to 3.5, 3.5 to 4.0, 4.0 to 4.5, 4.5 to 5.0, 5.0 to 5.5, or 5.5 to 6.0, or 6.0 to 6.5, or 6.5 to 7.0. The pH of the feed solution in step (i) may be about 2.5 to 3.5. It may be about 3.0.

[0024] The aqueous feed solution may be a leaching solution comprising at least two metals selected from nickel, cobalt, and manganese. Step (i) may include generating the feed solution. This may involve generating the leaching solution by the methods described in this specification. In one embodiment, the feed solution may be a leaching solution, or the leaching solution may be used to provide an aqueous feed solution. In this embodiment, the term "for providing an aqueous feed solution" may mean using the leaching solution directly as an aqueous feed solution, or it may mean further processing or treating the leaching solution, and the subsequently processed or treated solution being the aqueous feed solution of step (i).

[0025] Therefore, in one embodiment of the present invention, the method may include (or step (i) may include) the following steps before step (i): [A.] Provides a feed mixture comprising at least one metal selected from nickel, cobalt, and manganese, wherein the feed mixture is one of an oxidizing feed, a reducing feed, or an unoxidized feed, wherein: The oxidizing feedstock has at least one metal with an oxidation state greater than 2 more than the metal with an oxidation state less than 2; The reduction feed contains at least one metal with an oxidation state less than 2 and more metals with an oxidation state greater than 2, or contains at least one metal substantially entirely in an oxidation state of 2 and at least some of the at least one metal in sulfide form; and The unoxidized feed contains at least one metal substantially entirely in an oxidation state of 2, and substantially none of the at least one metal in its sulfide form; [B.] The feed mixture is treated with an aqueous solution to form a leachate containing the at least one metal, wherein the pH of the aqueous solution is such that the pH of the leachate is between about -1 and about 7 (or between about -1 and about 6; or between about 1 and about 7; or between about 1 and about 6), and wherein: If the feed mixture is an oxidizing feed, the treatment further includes adding a reagent containing a reducing agent; and If the feed mixture is a reducing feed, the process further includes adding a reagent containing an oxidant; The leachate contains at least one metal in an oxidation state of 2.

[0026] In this embodiment, the phrase "has more of" (e.g., in the phrase "the oxidizing feed has an oxidation state greater than 2 more than the at least one metal with an oxidation state less than 2") should be considered as "having a greater molar concentration." The term "substantially all" may mean at least 90%, or at least 95%, or at least 99%, or at least 99.5%, or at least 99%, each in moles. The various options and embodiments described below may be used individually or in any suitable combination.

[0027] In one embodiment, the at least one metal may be at least two metals.

[0028] In one embodiment, step (i) includes: A feed mixture comprising at least two of the metals is provided, wherein the feed mixture is one of an oxidizing feed, a reducing feed, or an unoxidized feed, wherein: The oxidizing feed comprises at least two metals having an oxidation state greater than 2 than an oxidation state less than 2; The reduction feed comprises at least two metals having an oxidation state less than 2 and more metals having an oxidation state greater than 2, or comprises at least two metals substantially all having an oxidation state of 2 and at least some of the at least two metals in sulfide form; and The unoxidized feed contains at least two metals that are substantially all in an oxidation state of 2, and substantially none of the at least two metals in their sulfide form; The feed mixture is treated with an aqueous solution to form a leachate containing at least two of the metals, wherein the pH of the aqueous solution is such that the pH of the leachate is between about -1 and about 6 (or between about 1 and about 6), and wherein: If the feed mixture is an oxidizing feed, the treatment further includes adding a reagent containing a reducing agent; and If the feed mixture is a reducing feed, the process further includes adding a reagent containing an oxidant; The leachate contains at least two metals with an oxidation state of 2. In order to provide the aqueous feed solution, which is an extract.

[0029] Examples of oxidation feeds as defined above may include Ni(II), Co(III), and Mn(O) in a molar ratio of 5:2:1, or Ni(III), Co(II), and Mn(III) in a molar ratio of 2:1:1, or a mixture of Ni(II) and Mn(III) in any proportion in the absence of Co. Examples of reduction feeds as defined above may include a mixture of Ni(II), Co(II), and Mn(II) in any proportion, or a mixture of Ni(O), Mn(II), and Co(II) in a molar ratio of 5:2:1. It should be noted that in this specification, oxidation state (II) may be referred to as oxidation state 2 or +2, and these terms are used interchangeably. In one embodiment, the leachate comprises Co(II), Mn(II), and Ni(II).

[0030] In one embodiment, nickel, cobalt, and / or manganese laterite ores are typically considered as oxidizing feeds. In another embodiment, mixed hydroxide precipitates, mixed carbonate precipitates, or oxides or carbonates of nickel, cobalt, and / or manganese are typically considered as oxidizing or unoxidizing feeds. In one embodiment, nickel and / or cobalt sulfide ores or concentrates are typically considered as reducing feeds. In another embodiment, mixed sulfide precipitates are typically considered as reducing feeds. In another embodiment, iron-nickel, nickel pig iron, and nickel, cobalt, and / or manganese metal alloys are typically considered as reducing feeds. In another embodiment, recycled materials from lithium-ion battery packs are typically considered as oxidizing feeds.

[0031] In one embodiment, the mixture comprises nickel, cobalt, and manganese, thereby the aqueous solution comprises nickel, cobalt, and manganese. In another embodiment, one of these metals is not present in the mixture, thereby the aqueous solution comprises two of nickel, cobalt, and manganese but not the other.

[0032] In one embodiment, the feed mixture is an oxidizing feed, and the reagent contains a reducing agent. In another embodiment, the feed mixture is a reducing feed, and the reagent contains an oxidizing agent. In yet another embodiment, the feed mixture is a non-oxidizing feed, and neither a reducing agent nor an oxidizing agent is used.

[0033] The previously disclosed method uses a 4 M sulfuric acid solution for the leaching step, which is an extremely strong acid with a pH below 0. This is a highly corrosive acid and will cause significant dissolution of impurity elements, including iron, aluminum, and copper. If elements such as iron and aluminum dissolve, more acid will be consumed in the leaching stage, and more alkali or other reagents will be consumed in the precipitation separation and / or removal or other impurity separation and / or removal stages.

[0034] In contrast, the leaching step described above involves treating the mixture in an aqueous solution with a pH of approximately 1 to approximately 7 or approximately 1 to approximately 6 (a sulfuric acid solution at pH 1 is equivalent to approximately 0.05 M sulfuric acid). At this lower acidic pH, the dissolution of iron and aluminum, and to a lesser extent, of copper, is less favorable. Conversely, nickel, cobalt, and manganese are all soluble at pH levels below approximately 6 when in their +2 oxidation state. This step provides a surprisingly efficient and cost-effective method for preparing solutions suitable for co-precipitating at least two of Ni, Mn, and Co with increased purity, compared to prior art methods utilizing more acidic conditions. It should be noted that those skilled in this art can readily determine the amount and concentration of the specific acid required to achieve the target pH through routine experiments and / or theory.

[0035] The mixture may be a solid mixture. It may be a mixture (e.g., a slurry) in which at least a portion of nickel, manganese, and cobalt are in solid form. In one embodiment, the mixture is a mixed hydroxide precipitate (or "MHP"). MHP is a solid mixed nickel-cobalt hydroxide precipitate, a known intermediate product in the commercial processing of nickel-bearing ores. MHP may be derived from nickel sulfide or laterite. Such MHP can be used as an oxidizing feedstock. This is because at least a small portion of the manganese and cobalt in the MHP can be in oxidized form. MHP may originate from a crude recycling process or any aqueous solution containing nickel and cobalt.

[0036] In one embodiment, the mixture is a product (typically a solid residue) obtained from a selective acid leaching (SAL) process disclosed in PCT / AU2012 / 000058, wherein the pH and the amount of oxidant are controlled to selectively dissolve at least a portion of the nickel in the solution. In this method, the amount of oxidant typically oxidizes at least a portion of the cobalt and / or manganese to Co(III). Therefore, using this process typically provides an oxidation feed. In the SAL process, MHP is used as discussed above.

[0037] Therefore, in one embodiment, the method includes the following steps prior to processing: (a) Contacting an MHP containing at least two metals with an acidic solution (which may contain an oxidizing agent) at a certain pH such that one of the metals (especially cobalt) is stable in the solid phase and the other of the metals dissolves in the acidic solution; and (b) Separating the solid phase from the acidic solution, wherein the solid phase contains at least two of the metals, wherein the solid phase forms at least a portion of the feed mixture.

[0038] In a particular form of this embodiment, these steps include: (a) Contacting an MHP containing at least nickel and cobalt, and optionally manganese, with an acidic solution (which may contain an oxidizing agent) at a given pH, such that cobalt is stabilized in the solid phase and nickel is dissolved in the acidic solution; and (b) Separating the solid phase from the acidic solution, wherein the solid phase contains at least two metals, one of which is cobalt; wherein the solid phase forms at least a portion of the feed mixture. In this embodiment, the solid phase containing at least two metals may be a feed mixture.

[0039] In one embodiment, the MHP is washed prior to step (a). The MHP may be treated with an oxidant during the washing step.

[0040] In one embodiment, the feed mixture comprises cobalt and nickel, and step A comprises the following steps: (a) Contacting a mixed hydroxide precipitate and / or a mixed carbonate precipitate containing at least cobalt and nickel with an acidic solution containing an oxidant at a specific pH, such that cobalt is stabilized in the solid phase and nickel is dissolved in the acidic solution; and (b) Separating the solid phase from the acidic solution, wherein the solid phase contains at least two metals, one of which is cobalt; wherein the solid phase forms at least a portion of the feed mixture.

[0041] In one embodiment, cobalt is stabilized in the solid phase as Co(III). In one embodiment, manganese is stabilized in the solid phase of step (a) as Mn(III).

[0042] The pH of the acidic solution, aqueous solution, or leachate in step (a) may be from about 1 to about 6, or from about 2 to 6, 2 to 5, 2 to 4, 2 to 3, 3 to 5, 3 to 6, 4 to 6, or 4 to 5, for example, about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, or 6. The pH of step (a) may be the final pH at the end of step (a). The pH of step (a) may be the pH throughout step (a).

[0043] The oxidant in step (a) or step B may be selected from the group consisting of: persulfates, peroxides, permanganates, perchlorates, ozone, mixtures containing oxygen and sulfur dioxide, oxides, and chlorine; for example, sodium persulfate or potassium persulfate, sodium permanganate or potassium permanganate, ozone, magnesium or hydrogen peroxide, chlorine or sodium perchlorate or potassium perchlorate. It may be a persulfate or permanganate. It may be sodium persulfate or potassium persulfate, sodium peroxyhydrosulfate or potassium peroxyhydrosulfate, or sodium permanganate or potassium permanganate.

[0044] In one embodiment of step (a), an oxidant of a combination molar amount of metal, which is stable in the solid phase, is added at a stoichiometric amount between about 70% and about 500%, for example, between about 80% and 400%; between 80% and 200%, or between 100% and 150%, for example, about 70%, 80%, 90%, 100%, 110%, 120%, 125%, 130%, 140%, 150%, 200%, 250%, 300%, 350%, 400%, 450, or 500%.

[0045] The temperature in step (a) may be greater than about 20°C but less than about 120°C, or greater than about 50°C but less than about 100°C, or about 60°C to about 90°C. It may be about 25, 30, 40, 50, 60, 70, 80, 90, 95, 100, 105, 110 or 115°C.

[0046] In step (b), the separation step can be a filtering step.

[0047] In one embodiment, the method may include a step of removing impurities from a feed mixture prior to the treatment, the feed mixture comprising at least two metals selected from nickel, cobalt, and manganese. The method may include contacting a mixture (or precursor) comprising at least one metal (or at least two of the metals) with a weak acid leaching solution (which may provide at least a portion of the feed mixture). The concentration of the weak acid leaching solution may be from about 0.005 M to about 0.5 M acid, or from about 0.01 M to 0.3 M, 0.01 M to 0.1 M, 0.02 M to 0.08 M, 0.03 M to 0.07 M, 0.04 M to 0.06 M, or 0.05 M to 0.1 M acid, for example, about 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 M acid. The acid in the weak acid leaching solution may be an inorganic acid or may be an organic acid. Inorganic acids may be selected from the group consisting of sulfuric acid, hydrochloric acid, and nitric acid. The organic acid can be acetic acid or formic acid. Other acids are also suitable. Sulfuric acid can be used as a weak acid to leach from the solution.

[0048] Step (a) can be performed at any suitable pressure (typically atmospheric pressure). Step (a) can provide a slurry. The slurry can have about 1% by weight solids to about 40% by weight solids, or about 5% by weight solids to about 40% by weight solids, or about 10% by weight solids to about 30% by weight solids, for example about 1, 5, 10, 15, 20, 25, 30, 35 or 40% by weight solids.

[0049] Following step (a), the solids can be separated from the liquid, for example, by filtration. The solids can be used as the feed mixture in step B. Step (a) can be applied to remove and / or separate impurities selected from one or more of calcium, magnesium, and zinc. It can also remove and / or separate other impurities, either additionally or alternatively.

[0050] In another embodiment, the feed mixture is a product derived from or obtained from a lithium-ion battery pack, particularly from the cathode material of a lithium-ion battery pack. It may be derived from recycled NMC material. It may contain more than about 1% by weight, or more than a combination of about 2, 3, 4, 5, 10, 20, 30, 40, 50, or 60% by weight of nickel, dry weight. It may contain more than about 0.1% by weight, or more than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 10, 20, 30, or 35% by weight of nickel, dry weight. It may contain more than about 0.1% by weight, or more than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, or 10% by weight of cobalt, dry weight. It may include more than about 0.1% by weight or more than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 10 or 15% by weight of manganese on a dry weight basis.

[0051] Therefore, in another embodiment, prior to this treatment, the method may include a step of separating the cathode material from the discharged lithium-ion battery pack. The separation step may include chopping or crushing the battery pack. The separation step may include removing the casing of the lithium-ion battery pack. The separation step may include separating the casing, electrolyte, anode, and cathode. The separated cathode material may form a mixture to be treated, or the mixture to be treated may be derived from the cathode material separated in the first-state method.

[0052] When the cathode material is manufactured, the cathode is calcined, which oxidizes the nickel, cobalt, and manganese. Therefore, after use and recycling, the used cathode material exhibits a chemical state very similar to SAL processing residues. Thus, the used cathode material can be used in the method of the first state of this invention.

[0053] In one embodiment, the mixture to be treated may be a product (especially a solid residue) obtained from a selective acid leaching (SAL) process disclosed in PCT / AU2012 / 000058 (as described above); a product from a recycled lithium-ion battery pack; a product from recycled NMC materials; or a combination thereof.

[0054] In one embodiment, the feed is a mixture. In another embodiment, it is a filter cake, such as a wet filter cake. In yet another embodiment, it is a slurry. The slurry may have about 1% by weight solids to about 40% by weight solids, or 5% by weight solids to about 40% by weight solids, or about 10% by weight solids to about 30% by weight solids, for example about 5, 10, 15, 20, 25, 30, 35, or 40% by weight solids.

[0055] In the methods of the above embodiments having steps A and B, at least a portion of at least one metal (or at least two metals) selected from nickel, cobalt, and / or manganese in the feed mixture may be in an oxidized state, i.e., an oxidation state greater than 2. As discussed above, most of the nickel, manganese, and cobalt present in the solid residue obtained from the SAL process may be in an oxidized state. Due to the poor solubility associated with these oxidized metal components, the solubility of these metals in aqueous solutions with a pH of about 1 to about 6 can be significantly improved by treatment with a reducing agent. Cobalt, manganese, and nickel, thus reduced to oxidation state 2, may selectively dissolve in the aqueous solution relative to one or more impurities (or leaching impurities) in the solution.

[0056] In one embodiment, at least about 5%, 10%, 20%, 30%, 40%, 50%, or 60% of at least one metal (or at least two metals) selected from cobalt, manganese, and nickel is in an oxidized state in the treated feed mixture.

[0057] Cobalt may be oxidized in the form of Co(III) and / or Co(IV); especially Co(III). Manganese may be oxidized in the form of one or more of Mn(III), Mn(IV) and Mn(V); usually Mn(III). Nickel may be oxidized in the form of Ni(III) and / or Ni(IV), usually Ni(III). The mixture may also contain a large amount of cobalt, manganese and / or nickel in the desired (II) state.

[0058] However, the solubility profiles of some major leached impurities in the solid residue (particularly iron (Fe), aluminum (Al), and lower levels of copper (Cu)) overlap to some extent with those of the desired nickel, manganese, and cobalt components. For example, the desired +2 oxide forms of nickel, manganese, cobalt, and iron (Fe(II)) are relatively soluble between approximately pH 3 and approximately 7, while their oxidized forms only become significantly soluble in aqueous solutions below approximately pH 3. In the case of aluminum and copper, although these leached impurities do not exhibit the same oxidation / reduction behavior as nickel, manganese, and cobalt, they are significantly soluble in aqueous solutions below approximately pH 3 and approximately pH 4, respectively.

[0059] In one embodiment, the feed mixture may contain one or more leaching impurities. The one or more leaching impurities may be selected from the group consisting of: iron, aluminum, copper, barium, cadmium, calcium, carbon, chromium, lead, lithium, magnesium, potassium, fluoride, phosphorus, sodium, silicon, scandium, sulfur, titanium, zinc, arsenic, and zirconium.

[0060] It should be understood that, in most cases, the type and amount of these leached impurities will depend largely on how much the solid residue has been processed and what materials were used as starting materials before the method was carried out. For example, if the solid residue is obtained directly from the SAL process, it may contain significantly more iron (Fe) and aluminum (Al) than if the residue is obtained directly from the cathode active material (CAM) itself, especially if the CAM has been partially processed through a recycling process.

[0061] In one embodiment, the aqueous solution used for treatment comprises a leaching agent. The leaching agent may be an acid. The acid may be used to provide a pH of about 1 to about 7, or about 1 to about 6. The leaching agent may be an inorganic acid or an organic acid. Inorganic acids may be selected from the group consisting of sulfuric acid, hydrochloric acid, and nitric acid. Organic acids may be selected from acetic acid or formic acid. Other acids may also be suitable. The leaching agent may be sulfuric acid.

[0062] The pH of the aqueous solution may (or may consequently result in the pH of the leachate) be less than 7.0, or less than 6.75, 6.50, 6.25, 6.0, 5.75, 5.50, 5.25, 5.0, 4.75, 4.50, 4.25, 4.0, 3.75, 3.50, 3.25, 3.0, 2.75, 2.50, or 2.0. The pH of the aqueous solution may (or may consequently result in the pH of the leachate) be greater than 2.0, or greater than 2.25, 2.50, 2.75, 3.0, 3.25, 3.50, 3.75, 4.0, 4.25, 4.50, 4.75, 5.0, 5.25, 5.50, or 5.75. In some embodiments, the pH of the aqueous solution may (or may consequently make the pH of the leachate) be 1.0 to 4.0, 2.0 to 4.0, 4.0 to 6.0, 2.0 to 3.0, 3.0 to 4.0, 4.0 to 5.0, or 5.0 to 6.0, or 6.0 to 7.0. In some embodiments, the pH of the aqueous solution may (or may consequently make the pH of the leachate) be 1.0 to 1.5, 1.5 to 2.0, 2.0 to 2.5, 2.5 to 3.0, 3.0 to 3.5, 3.5 to 4.0, 4.0 to 4.5, 4.5 to 5.0, 5.0 to 5.5, or 5.5 to 6.0, or 6.0 to 6.5, or 6.5 to 7.0. The pH of the aqueous solution may be about 2.5 to 3.5. It may be about 3.0. The inventors have found that if the pH is below 1, more leached impurities dissolve in the aqueous solution. However, if the pH is higher than 6 or 7, the aqueous solution's ability to dissolve the required +2 oxidation state of nickel, cobalt, and manganese is reduced. The pH in step B can be the final pH of the solution at the end of the step, i.e., the pH of the leachate at the end of step B. The pH in step B can also be the pH throughout the entire step.

[0063] In one embodiment, the method may include the step of adding a leaching agent to an aqueous solution. In another embodiment, it may include the step of controlling the pH of the aqueous solution. In one embodiment, the pH of the aqueous solution may be controlled by adding an acidic leaching agent as defined above. In another embodiment, the pH of the aqueous solution may be controlled by adding a base. Exemplary bases may include alkali metal or alkaline earth metal hydroxides, such as sodium hydroxide. However, the base may be a nickel, cobalt, or manganese-containing material, such as a fresh solid (such as a mixture to be treated, or a nickel, cobalt, and manganese precipitate, such as a hydroxide precipitate) or a hydroxide compound or a carbonate compound or a hydroxycarbonate compound. The advantage of using a nickel, cobalt, or manganese-containing material, especially one comprising at least one oxidized portion, is that the addition of this material also consumes the residual reducing agent in the solution and converts the conditions to oxidation to oxidize Fe²⁺ to Fe³⁺, because Fe³⁺ precipitates more favorably than Ni or Co.

[0064] In one embodiment, the leaching agent is added to the aqueous solution (or "leaching solution") at a controlled rate. In one embodiment, the leaching agent may be added incrementally until the solution reaches the desired final pH (the desired final pH may be as described for the pH of the aqueous solution above). In another embodiment, all the leaching agent may be added to the aqueous solution in one step. In another embodiment, the leaching agent may be added gradually during the treatment process (i.e., within a predetermined time period discussed elsewhere herein). In some embodiments, the reagent is combined with the aqueous solution and then added to the feed mixture. In other embodiments, the aqueous solution is added to the feed mixture to achieve the desired pH, and then the reagent is added. In another embodiment, the reagent is combined with the aqueous solution after the aqueous solution has been combined with the feed mixture.

[0065] The leaching agent can be added to the aqueous solution at a ratio of about 10,000 mol to about 20,000 mol of a mixture containing nickel, cobalt, and manganese per metric ton; for example, at a ratio of about 12,000 mol to about 17,000 mol of a mixture containing nickel, cobalt, and manganese per metric ton; or at a ratio of 14,000 mol to 14,500 mol of a mixture containing nickel, cobalt, and manganese per metric ton. Sulfuric acid can be added to the aqueous solution at a ratio of about 1.0 to about 2.0 t H₂SO₄ per metric ton; or at a ratio of about 1.2 to about 1.7 t H₂SO₄ per metric ton; or at a ratio of about 1.4 t H₂SO₄ per metric ton.

[0066] The reducing agent can be selected from the group consisting of: hydrogen, SO2 gas, sulfites (such as sodium metabisulfite), organic acids, sulfides (such as nickel sulfide, sodium sulfide, potassium sulfide, cobalt sulfide or manganese sulfide, or sodium hydrosulfide, potassium hydrosulfide, cobalt hydrosulfide or manganese hydrosulfide), and hydrogen peroxide or combinations thereof. It can be SO2 gas or sodium metabisulfite or combinations thereof. It can be SO2 gas. Combinations of reducing agents can be used. In one embodiment, the reducing agent can be selected from the group consisting of hydrogen and SO2 gas. Advantageously, both hydrogen and SO2 gas are sufficiently strong to reduce cobalt, manganese, and nickel without introducing any additional impurities into the leaching solution. When selecting a suitable reducing agent, it is preferable to choose a reagent that will not introduce impurities into the solution, or alternatively, only introduce impurities that can be easily removed and / or separated. In one embodiment, the reducing agent is SO2 gas. The presence of SO2 gas in the solution can also generate acid in situ (e.g., via reaction with the solution or oxidizing material). In one embodiment, the reducing agent is a gas at atmospheric pressure and room temperature. In another embodiment, the reducing agent is a liquid at atmospheric pressure and room temperature. In yet another embodiment, the reducing agent is a solid at atmospheric pressure and room temperature.

[0067] Aqueous solutions and (if used) reagents can be added independently over time intervals of approximately 0.25 to approximately 5 hours, or over time intervals of approximately 0.25 to 1, 0.25 to 0.5, 0.5 to 1, 0.5 to 2, 1 to 4, 1 to 3, 1 to 2, 2 to 5, 3 to 5, or 3 to 4 hours, for example, over time intervals of approximately 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 hours. However, sometimes the addition of one or both of these may take more than 5 hours. They can be added independently or together. They can be added simultaneously, sequentially, or (if added in batches or semi-continuously) alternately. They can each be added independently in batches or continuously, or in a semi-continuous manner (i.e., continuously but not periodically). The reagent may be added at approximately 70% to approximately 500%, or approximately 100% to 500%, 200% to 500%, 300% to 500%, 100% to 300%, 70% to 200%, 70% to 100%, or 70% to 150% of the two or more metals to be oxidized or reduced, for example, at stoichiometric ratios of approximately 70%, 80%, 90%, 100%, 125%, 150%, 175%, 200%, 250%, 300%, 350%, 400%, 450%, or 500%, but in some cases ratios exceeding these ranges may also be suitable.

[0068] In one embodiment, the reducing agent is not hydrogen peroxide. The previously described methods using hydrogen peroxide can oxidize any iron present and reduce nickel, cobalt, and manganese in recycled cathode materials. In these processes, large amounts of hydrogen peroxide (a relatively weak reducing agent for nickel, cobalt, and manganese) are used, meaning that there is very little control during the reduction reaction. Furthermore, hydrogen peroxide is a relatively expensive reagent and necessitates the addition of other acids, and it also causes significant dilution due to the associated water.

[0069] The inventors have advantageously discovered that, in order to selectively dissolve nickel, manganese and cobalt in their oxidized forms relative to various leaching impurities in a mixture, it is necessary to convert these oxidized forms of nickel, manganese and cobalt in the mixture into the desired +2 oxidation state so that they are soluble at a pH of about 1 to about 6.

[0070] In one embodiment, the method may include the step of adding a reducing agent to an aqueous solution. In another embodiment, it may include the step of controlling the addition of a reducing agent to an aqueous solution. The addition of the reducing agent to the aqueous solution may be controlled such that the oxidized cobalt, manganese, and / or nickel components are substantially reduced to the desired +2 oxidation state, while minimizing the reduction rate of major leaching impurities such as iron (Fe), which have a wide pH range of solubility when reducing Fe(II) form. In one embodiment, the method of the first state sample may be carried out under conditions where cobalt, manganese, and / or nickel are preferentially oxidized relative to leaching impurities in the mixture. Such leaching impurities may be at least one of the group consisting of (especially all of the group consisting of): iron, aluminum, copper, iron, barium, cadmium, calcium, carbon, chromium, lead, lithium, magnesium, potassium, phosphorus, sodium, silicon, fluorine, sulfur, titanium, zinc, and zirconium; especially aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium.

[0071] The inventors have advantageously discovered that, in relation to the reduction reaction, nickel oxide should be reduced first, followed by cobalt, then manganese, and finally iron. Therefore, in one embodiment, the amount of reducing agent added to the mixture is selected to reduce the oxidized nickel, cobalt, and manganese, but such that iron is not substantially oxidized.

[0072] In one embodiment, a reducing agent of a combined molar amount of cobalt oxide, manganese oxide, and nickel oxide (some of which may be absent) is added to an aqueous solution in amounts between about 0.5 and about 2 stoichiometric equivalents; or between about 0.7 and 1.5, 0.8 and 1.2, or 0.9 and 1.1 stoichiometric equivalents. About 1 stoichiometric equivalent, or about 0.5, 0.75, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5, or 5 stoichiometric equivalents may be added. The inventors have advantageously found that one stoichiometric equivalent of reducing agent is generally sufficient to reduce one stoichiometric equivalent of nickel, manganese, or cobalt oxide. The reducing agent may be added to an aqueous solution in a ratio of about 3,000 mol to about 10,000 mol of reducing agent per metric tonne of feed mixture; or in a ratio of about 5,000 mol to 8,000 mol or 6,000 mol to 6,500 mol of reducing agent per metric tonne of feed mixture. SO2 can be added to the aqueous solution at a ratio of about 0.2 to about 0.6 metric tons of SO2 per metric ton of feed mixture; or at a ratio of 0.3 to 0.5 metric tons of SO2 per metric ton of feed mixture; for example, at a ratio of about 0.3, 0.4 or 0.5 metric tons of SO2 per metric ton of feed mixture.

[0073] In one embodiment, an oxidant of a combined molar amount of reduced cobalt, reduced manganese, and reduced nickel (some of which may be absent) is added to an aqueous solution in amounts between about 0.5 and about 5 stoichiometric amounts; or between about 0.5 and 2, 0.7 and 1.5, 0.8 and 1.2, or 0.9 and 1.1 stoichiometric amounts. About 1 stoichiometric amount, or about 0.5, 0.75, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 4.5, or 5 stoichiometric amounts may be added. In one embodiment of step B, an oxidant is added in stoichiometric amounts of combined molar amounts of reduced cobalt, reduced manganese, and reduced nickel (some of which may be absent); for example, between about 80% and 400%; between 80% and 200%; or between 100% and 150%, for example, about 70%, 80%, 90%, 100%, 110%, 120%, 125%, 130%, 140%, 150%, 200%, 250%, 300%, 350%, 400%, 450%, or 500%.

[0074] In one embodiment, a reagent (especially a reducing agent) is added to an aqueous solution (or "leaching solution") at a controlled rate. The reagent (especially a reducing agent) may be added at a continuous rate over a specific time period. Suitable time periods may be about 15 minutes to about 3 hours; or about 30 minutes to about 2 hours; or about 30 minutes to about 1 hour; or about 1 to about 3 hours; or about 1 to about 2 hours. The inventors have found that slower addition rates generally provide greater selectivity for leaching impurities, but faster addition rates generally provide improved yields.

[0075] In one embodiment, the treatment is carried out in a sealed container. Advantageously, the use of a sealed container allows for control of gas loss, greater control over the reduction or oxidation reaction (where appropriate), and slower addition of the reducing or oxidizing agent (especially when the reducing or oxidizing agent is a gas). In one embodiment, the treatment is carried out at atmospheric pressure. In another embodiment, it is carried out at 0.9 to 2.0 atmospheres, or 1.0 to 1.5 atmospheres, for example, about 1, 1.1, 1.2, 1.3, 1.4, or 1.5 atmospheres. Performing the treatment at slightly overpressured conditions can be suitable for limiting excessive gas.

[0076] The inventors have discovered that, for at least some reagents (such as some reducing agents), the addition of a reagent can affect the pH of an aqueous solution. Therefore, in some embodiments, the pH of the solution may need to be controlled, for example, by adding an acid or a base.

[0077] In some embodiments, when a reducing agent is used, controlling the pH and the reduction reaction will allow selective dissolution of nickel, cobalt, and manganese while limiting the leaching of iron, aluminum, and copper to about 40% by weight or less; or to about 30%, 20%, 15%, or 12% by weight or less, respectively. Advantageously, by using this process, a significant portion of some leached impurities can be retained in the solid phase.

[0078] In another embodiment, the process provides a leachate comprising dissolved nickel, cobalt, and manganese, and a solid comprising at least one (or all) of the group consisting of: iron, aluminum, copper, barium, cadmium, calcium, carbon, chromium, lead, lithium, magnesium, potassium, phosphorus, sodium, silicon, fluorine, sulfur, titanium, zinc, and zirconium; or aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium.

[0079] In one embodiment, step B is performed at a temperature at which the aqueous solution remains liquid. In one embodiment, it is performed at a temperature between about 0°C and about 100°C; or about 10°C to about 100°C; or about 20°C to about 100°C; or about 40°C to about 100°C; more particularly about 50°C to about 100°C; or about 60°C to about 100°C. In another embodiment, it is performed at a temperature between about 60°C and about 95°C (or about 60°C to about 90°C); or about 70°C to about 95°C; or about 75°C to about 95°C; or about 80°C to about 95°C. In one embodiment, it is performed at a temperature between about 0°C and about 100°C; or about 10°C to about 100°C; or about 20°C to about 100°C; or about 30°C to about 80°C; or about 40°C to about 70°C; or about 45°C to about 65°C; or about 45°C to about 80°C; or about 50°C to about 60°C. It can be carried out at approximately 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100°C or at approximately 55°C. The temperature of the aqueous solution may increase over time because the reaction / process is usually exothermic.

[0080] In one embodiment, step B may be performed at a temperature of 80 to 81.0, 81.0 to 82.0, 82.0 to 83.0, 83 to 84.0, 84.0 to 85.0, 85.0 to 86.0, 86.0 to 87.0, 87.0 to 88.0, 88.0 to 89.0, 89.0 to 90.0, 90.0 to 91.0, 91.0 to 92.0, 92.0 to 93.0, 93.0 to 94.0, or 94.0 to 95.0°C.

[0081] In one embodiment, step B may be performed for a predetermined time. As outlined above, the time required to process the first-state sample may be affected by factors such as the temperature at which the reaction takes place, the pH of the solution, and the reagents. However, in one embodiment, the processing may take place for at least about 10 minutes, or at least about 30 minutes, or at least about 1 hour, or at least about 2 hours. In one embodiment, it may take place for about 30 minutes to about 6 hours, or about 30 minutes to about 4 hours, 1 hour to 4 hours, 1 hour to 3 hours, or 2 hours to 3 hours, for example, about 2 hours or about 2.5 hours.

[0082] In one embodiment, the processing is carried out under mixing or agitation, such as stirring.

[0083] In one embodiment, the processing may be carried out using at least one container. The at least one container may be one container or two containers. These containers may be mixers and may be configured to mix liquids (which may include entrained solids) therein. These containers may be agitated. They may include stirrers.

[0084] The processing can be carried out in any suitable proportion of liquid to solid. In one embodiment, the solid-liquid mixture may contain at least about 1% solids (by weight), or at least about 2%, 3%, 4%, 5%, 10%, 15%, or 20% solids (by weight). In one embodiment, the solid-liquid mixture may contain about 3 to about 25% solids (by weight), or about 4 to 20%, 1 to 10%, 3 to 7%, or 4 to 6% solids (by weight). In one embodiment, the feed mixture and the aqueous solution together form a slurry.

[0085] The method may include the step of adding a reagent (such as an oxidizing agent or a reducing agent) to the aqueous solution after combining the feed mixture with the aqueous solution. The oxidizing agent may be a mixture containing at least two of nickel, cobalt, and manganese (i.e., the starting material to be treated). A manganese salt, carbonate, or hydroxide (usually a carbonate or hydroxide) may also be added in this step. A suitable manganese salt may be MnCO3. Suitable carbonates may be selected from the group consisting of MnCO3, Ni(OH)(CO3)0.5, NiCO3, CoCO3, Co(OH)2, Na2CO3, and CaCO3. Suitable hydroxides may be selected from the group consisting of Ni(OH)2, Ni(OH)(CO3)0.5, NaOH, and Ca(OH)2. This step may be carried out at any suitable temperature, typically as previously described for the treatment. This step may last for any duration, for example, about 30 minutes to about 10 hours, or about 3 hours to about 10 hours, or about 4 hours to about 8 hours. This step avoids the need to remove or separate leached impurities such as magnesium, sodium, calcium, and zinc. This step also consumes any remaining reducing agents in the solution.

[0086] In one embodiment, the method may include adding an oxidizing agent and / or a reducing agent to neutralize any excess reducing agent and / or oxidizing agent in the solution. In another embodiment, the method may include adding a base to the solution to increase the pH to, for example, a pH higher than in step B but lower than pH 7 (e.g., pH 6). The method may include a step of filtering the solution before neutralizing excess reducing agent and / or oxidizing agent or increasing the pH.

[0087] Following treatment, impurities (or "leached impurities") can be removed from and / or separated from the leachate by any suitable method. In this context, the terms "impurity" or "leached impurity" refer to metals, complexes, compounds, or elements that are not nickel, cobalt, manganese, water, OH-, H+, H3O+, sulfates, or carbonates. Those skilled in the art can select appropriate techniques for removing impurities based on their nature. For example, at least a portion of the leached impurities may be in solid form. In one embodiment, at least one separation technique selected from the group consisting of: decantation, filtration, cementation, centrifugation, and sedimentation, or any combination of two or more thereof, can be used to remove and / or separate solid leached impurities from the aqueous solution. Exemplary solid leached impurities may include at least one selected from the group consisting of: iron, aluminum, copper, barium, cadmium, carbon, chromium, lead, silicon, sulfur, titanium, zinc, and zirconium.

[0088] The leachate may contain at least one liquid leaching impurity. Exemplary liquid leaching impurities in the leachate may be at least one leaching impurity selected from the group consisting of: arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, vanadium, lanthanum, ammonium, sulfite, fluorine, fluoride, chloride, titanium, scandium, iron, zinc, and zirconium, silver, tungsten, vanadium, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, lead, niobium, or combinations thereof; particularly arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, vanadium, lanthanum, titanium, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, and niobium, or combinations thereof.

[0089] In one embodiment, the mass ratio of at least one metal (selected from the group consisting of nickel, cobalt, and manganese; particularly at least two or three metals) to at least one liquid leaching impurity is less than 1:50 or less than 1:20, or less than 10:1, or less than 1:1, or less than 10:1, or less than 100:1, or less than 500:1, or less than 1000:1, or less than 5000:1, or less than 10,000:1, or less than 50,000:1, or less than 200,000:1, or less than 500,000:1.

[0090] In another example, at least a portion of the leached impurities may be in liquid (or dissolved) form. In one embodiment, at least one separation technique selected from the group consisting of ion exchange, precipitation, absorption / adsorption, electrochemical reduction, and distillation, or any combination of two or more thereof, typically ion exchange, precipitation, and adsorption, or combinations thereof. In this context, the term "impurity" or "leached impurity" refers to metals that are not cobalt, nickel, or manganese, but may also encompass metals that are not the desired nonmetal or semimetal. Exemplary liquid leaching impurities may include arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, sodium, lithium, potassium, phosphorus, tetrafluoroborate, hexafluorophosphate, vanadium, lanthanum, ammonium, sulfite, fluorine, fluoride, chloride, titanium, iron, scandium, zinc, and zirconium, or combinations thereof.

[0091] In one embodiment, the concentration of alkali metal (such as Na, Li, K) (or at least one alkali metal) liquid leaching impurities in the leachate is less than or equal to 100,000 ppm, or less than or equal to 80,000 ppm, or less than or equal to 60,000 ppm, or less than or equal to 50,000 ppm, or less than or equal to 40,000 ppm, or less than or equal to 30,000 ppm, or less than or equal to 20,000 ppm, or less than or equal to 15,000 ppm, or less than or equal to 10,000 ppm, or less than or equal to 7,000 ppm, or less than or equal to 5,000 ppm, or less than or equal to 4,000 ppm, or less than or equal to 3,000 ppm, or less than or equal to 2,500 ppm, or less than or equal to 2,000 ppm. In another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to an alkali metal liquid leaching impurity (or at least one alkali metal impurity) may be greater than about 1:10, or greater than about 1:5, or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or greater than about 120:1, or greater than about 150:1, or greater than about 180:1 or greater than about 200:1. In another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to an alkali metal liquid leaching impurity (or at least one alkali metal impurity) may be less than about 1:1, or less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1, or less than about 200:1. In another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to an alkali metal liquid leaching impurity (or at least one alkali metal impurity) may be from about 1:10 to 23,000:1, or from about 1:10 to 100,000,000:1, or from about 1:10 to 300,000,000:1.

[0092] In one embodiment, the concentration of anionic liquid leaching impurities (such as F- and Cl-, but excluding oxides, hydroxides, sulfates, or carbonates) (or at least one anionic liquid impurity) in the leachate is less than or equal to 100,000 ppm, or less than or equal to 80,000 ppm, or less than or equal to 60,000 ppm, or less than or equal to 50,000 ppm, or less than or equal to 40,000 ppm, or less than or equal to 30,000 ppm, or less than or equal to 20,000 ppm, or less than or equal to 10,000 ppm, or less than or equal to 5,000 ppm, or less than or equal to 4,000 ppm, particularly less than or equal to 3,000 ppm, or less than or equal to 2,500 ppm, or less than or equal to 2,000 ppm. In another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to anionic species liquid leaching impurities (or at least one anionic species liquid impurity) may be greater than about 1:10, or greater than about 1:5, or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or greater than about 120:1, or greater than about 150:1, or greater than about 180:1 or greater than about 200:1. In another embodiment, the molar ratio (or mass ratio) of at least one metal (or at least two metals) in the leachate to anionic species liquid leaching impurities (or at least one anionic species impurity) may be less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1 or less than about 200:1.

[0093] In another embodiment, the concentration of alkaline earth metal liquid leaching impurities (such as Ca and Mg) (or at least one alkaline earth metal impurity) in the leachate is less than 50,000 ppm, or less than 40,000 ppm, or less than 30,000 ppm, or less than 20,000 ppm, or less than 10,000 ppm, or less than 5,000 ppm, or less than 1,000 ppm, or less than 800 ppm, or less than 600 ppm, or less than 500 ppm, or less than 400 ppm, or less than 300 ppm, or less than 250 ppm, or less than 200 ppm. In another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to alkaline earth metal liquid leaching impurities (or at least one alkaline earth metal liquid impurity) is greater than about 500:1, or greater than about 1000:1, or greater than about 1500:1, or greater than about 2000:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to an alkaline earth metal liquid leaching impurity (or at least one alkaline earth metal liquid impurity) is about 300,000,000:1 to about 1:10; or greater than about 1:10, or greater than 1:1. In another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to an alkaline earth metal liquid leaching impurity (or at least one alkaline earth metal liquid impurity) is less than 1:10, or less than 1:5, or less than 1:1, or less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1, or less than about 200:1.

[0094] In another embodiment, the concentration of metallic and metalloid liquid leaching impurities (or at least one metallic or metalloid impurity) in the leachate is less than 250 ppm, particularly less than 50 ppm. Exemplary metallic and metalloid leaching impurities may be selected from the group consisting of: iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, scandium, zirconium, and titanium. In one embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to the metallic and metalloid liquid leaching impurities (or at least one metallic or metalloid liquid impurity) is less than 10,000:1, or less than 20,000:1, or less than 40,000:1, or less than 60,000:1, or less than 80,000:1, or less than 100,000:1, or less than 500,000:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to Fe impurities is about 300,000,000:1 to about 10,000:1, or greater than about 10,000:1, or greater than 12,000:1. In another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to Fe impurities is less than 10,000:1, or less than 20,000:1, or less than 100,000:1, or less than 500,000:1, or less than 1,000,000:1. In yet another embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to Al impurities is about 300,000,000:1 to about 10,000:1; or greater than about 10,000:1, or greater than 12,000:1. In one embodiment, the molar ratio of at least one metal (or at least two metals) in the leachate to the Al impurity is less than 10,000:1, or less than 20,000:1, or less than 100,000:1.

[0095] In one embodiment of the present invention, a method for generating a coprecipitate is provided, wherein the coprecipitate comprises at least one metal selected from nickel, cobalt, and manganese, the method comprising: [(i)] A feed mixture comprising the at least one metal and at least one impurity is provided, the feed mixture being one of an oxidizing feed, a reducing feed, or an unoxidized feed, wherein: The oxidizing feedstock has at least one metal with an oxidation state greater than 2 more than the metal with an oxidation state less than 2; The reduction feed contains at least one metal with an oxidation state less than 2 and more metals with an oxidation state greater than 2, or contains at least one metal substantially entirely in an oxidation state of 2 and at least some of the at least one metal in sulfide form; and The unoxidized feed contains at least one metal substantially entirely in an oxidation state of 2, and substantially none of the at least one metal in its sulfide form; The feed mixture is treated with an aqueous solution to form a leachate containing at least one metal, wherein the pH of the aqueous solution is such that the pH of the leachate is between about 1 and about 7, and wherein: If the feed mixture is an oxidizing feed, the treatment further includes adding a reagent containing a reducing agent; and If the feed mixture is a reducing feed, the process further includes adding a reagent containing an oxidant; The leachate contains at least one metal with an oxidation state of 2. In order to provide an aqueous feed solution containing at least one metal, the aqueous feed solution being a leaching solution; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, and as appropriate, to between about 6.2 and about 10 or between about 6.2 and about 9.2, in order to provide: (a) a precipitate containing the at least one metal; and (b) a supernatant containing the at least one impurity. In this embodiment, the method may further include the step of mixing at least one metal with an aqueous feed solution, wherein the at least one metal is selected from nickel, cobalt and manganese, such that step (ii) provides a coprecipitate containing at least two metals selected from nickel, cobalt and manganese (or containing three metals).

[0096] In one embodiment, in the feed solution of step (ii), 1% of the at least one impurity, or at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50% of the at least one impurity, particularly at least 60%, or at least 65%, or at least 70%, or at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95%, or at least 96%, or at least 97%, or at least 98%, or at least 99% of the at least one impurity, may be the supernatant after co-precipitation, or the washing solution after washing the coprecipitate, or a combination of both. The at least one impurity may also be a plurality of impurities. The amount of each impurity in the supernatant or washing solution, or in the aqueous feed solution thereof, may differ for each impurity.

[0097] In one embodiment of the present invention, a method for producing a coprecipitate comprising at least two metals selected from nickel, cobalt, and manganese is provided, the method comprising: [(i)] Provide a feed mixture comprising at least two of the metals, wherein the feed mixture is one of an oxidizing feed, a reducing feed, or an unoxidized feed, wherein: The oxidizing feed comprises at least two metals having an oxidation state greater than 2 than an oxidation state less than 2; The reduction feed comprises at least two metals having an oxidation state less than 2 and more metals having an oxidation state greater than 2, or comprises at least two metals substantially all having an oxidation state of 2 and at least some of the at least two metals in sulfide form; and The unoxidized feed contains at least two metals that are substantially all in an oxidation state of 2, and substantially none of the at least two metals in their sulfide form; The feed mixture is treated with an aqueous solution to form a leachate containing at least two of the metals, wherein the pH of the aqueous solution is such that the pH of the leachate is between about 1 and about 7, and wherein: If the feed mixture is an oxidizing feed, the treatment further includes adding a reagent containing a reducing agent; and If the feed mixture is a reducing feed, the process further includes adding a reagent containing an oxidizing agent; The leachate contains at least two metals with an oxidation state of 2. In order to provide an aqueous feed solution containing at least two of the metals, the aqueous feed solution being a leaching solution; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, so that the at least two metals co-precipitate with the feed solution.

[0098] In one embodiment, at least one impurity in the coprecipitate can be controlled by selective precipitation. In an aqueous feed solution, at least one impurity may precipitate as a coprecipitate in an initial amount of less than 100%, or less than 90%, or less than 80%, or less than 70%, or less than 50%, or less than 30%, or less than 10%, or less than 5%, or less than 1%. This is particularly true for alkaline earth metals such as Ca and Mg.

[0099] In one embodiment, at least one impurity may precipitate due to phenomena such as adsorption, absorption, substitution, atomic substitution, phase formation, secondary phase formation, mixed phase formation, coprecipitation, or liquid entrainment. Alkali metals (such as Li, Na, and K), ammonia / ammonium, sulfur (in sulfate or sulfite form), and to a lesser extent alkaline earth metals, Zn, and Cu can be removed by washing with high-purity water, acid, caustic alkali, sodium carbonate, or ammonia, or combinations thereof. After washing, less than 100%, less than 99%, less than 90%, less than 70%, less than 50%, less than 40%, less than 30%, less than 20%, less than 10%, less than 5%, or less than 1% of these species relative to the amount in the aqueous feed solution may be present in the final coprecipitate.

[0100] In step (i), one or more impurities may be separated and / or removed from the aqueous solution containing at least two of the metals (especially nickel, cobalt and manganese) in any suitable manner, for example as described elsewhere in this application.

[0101] Therefore, in another embodiment, a method is provided for producing a coprecipitate comprising at least two metals selected from nickel, cobalt, and manganese, the method comprising: [(i)] Provide an aqueous feed solution containing at least two of the metals and at least one impurity, and remove and / or separate one or more impurities from the feed solution as appropriate; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, so that the at least two metals co-precipitate with the feed solution.

[0102] In yet another embodiment, a method is provided for producing a coprecipitate comprising at least two metals selected from nickel, cobalt, and manganese, the method comprising: [(i)] Provide a feed mixture comprising at least two of the metals, wherein the feed mixture is one of an oxidizing feed, a reducing feed, or an unoxidized feed, wherein: The oxidizing feed comprises at least two metals having an oxidation state greater than 2 than an oxidation state less than 2; The reduction feed comprises at least two metals having an oxidation state less than 2 and more metals having an oxidation state greater than 2, or comprises at least two metals substantially all having an oxidation state of 2 and at least some of the at least two metals in sulfide form; and The unoxidized feed contains at least two metals that are substantially all in an oxidation state of 2, and substantially none of the at least two metals in their sulfide form; The feed mixture is treated with an aqueous solution to form a leachate containing at least two of the metals, wherein the pH of the aqueous solution is such that the pH of the leachate is between about 1 and about 7, and wherein: If the feed mixture is an oxidizing feed, the treatment further includes adding a reagent containing a reducing agent; and If the feed mixture is a reducing feed, the process further includes adding a reagent containing an oxidizing agent; The leachate contains at least two metals with an oxidation state of 2. To provide an aqueous feed solution comprising at least two of the metals and at least one impurity, the aqueous feed solution being a leaching solution, and, where appropriate, removing and / or separating one or more impurities (or at least a portion of the at least one impurity) from the feed solution; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, and as appropriate, to between about 6.2 and about 10 or between about 6.2 and about 9.2, so as to allow the at least two metals to coprecipitate with the feed solution (or to provide: (a) a coprecipitate containing the at least two metals; and (b) a supernatant containing at least a portion of the at least one impurity).

[0103] The step of removing and / or separating one or more impurities may be a step of removing and / or separating one or more impurities from the leachate.

[0104] Appropriate techniques for separating and / or removing impurities to the desired extent can be selected by a person skilled in the art based on the nature of the impurities. For example, at least a portion of the impurities may be in solid form. In one embodiment, at least one technique selected from the group consisting of: decantation, filtration, centrifugation, cementation, and sedimentation, or combinations thereof, can be used to separate and / or remove solid impurities from the feed solution (or leachate). Exemplary solid impurities may include at least one selected from the group consisting of: iron, aluminum, copper, barium, cadmium, carbon, chromium, lead, silicon, sulfur, titanium, zinc, and zirconium.

[0105] In another example, at least a portion of the impurities may be in liquid (or dissolved) form. In one embodiment, liquid (or dissolved) impurities may be removed from the feed solution (or leachate) using at least one separation technique selected from the group consisting of: ion exchange, precipitation, absorption / adsorption, electrochemical reduction, and distillation, or combinations thereof; particularly ion exchange, precipitation, and adsorption, or combinations thereof; or solvent extraction, ion exchange, precipitation, adsorption, and absorption, or combinations thereof. Exemplary liquid impurities may include iron, copper, zinc, calcium, magnesium, chromium, fluorine, lead, cadmium, silicon, and aluminum; particularly iron, copper, zinc, calcium, magnesium, silicon, and aluminum.

[0106] Ion exchange can be used to remove at least one impurity, particularly at least one metalloid or liquid metal impurity, or alkaline earth metal (liquid) impurity. Exemplary impurities that can be removed by ion exchange may include at least one of the following groups: magnesium, calcium, aluminum, iron, zinc, copper, chromium, cadmium, and scandium; particularly at least one of the following groups: aluminum, iron, zinc, copper, chromium, cadmium, and scandium. Ion exchange can be used to remove at least some zinc. Ion exchange can be carried out in at least two washing steps, particularly two washing steps. Ion exchange can be carried out at temperatures from 20°C to 60°C; or about 30°C to 50°C, 20°C to 40°C, or 40°C to 60°C; for example, at temperatures of about 20°C, 30°C, 40°C, 50°C, or 60°C. The pH of the ion exchange can be from about 2 to about 7, or from about 3 to about 7, or from about 3 to about 4, for example, about 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, or 7.

[0107] The removal and / or separation of impurities can be performed using a combination of techniques for removing solid and / or liquid and / or gaseous impurities. Therefore, it may include solid impurity removal and / or separation steps, and liquid impurity removal and / or separation steps. It may also include gaseous impurity removal and / or separation steps.

[0108] In one embodiment, the removal and / or separation of impurities can be performed using at least one container. The at least one container may be one or two containers. These containers may be sedimentators and can be configured to allow liquid (which may include entrained solids) to settle therein. These containers may include at least two outlets. The containers may include an upper outlet in the upper part of the container to provide a liquid outlet and a lower outlet in the lower part of the container to provide a settled solids outlet.

[0109] In one embodiment, step (i) may be performed using a plurality of containers. In one embodiment, step (i) may be performed using at least two containers (or mixers); particularly two containers (or mixers). In one embodiment, the removal and / or separation of impurities may be performed using at least two containers (or settling tanks); particularly two containers (or settling tanks).

[0110] In one embodiment, a mixture comprising at least one or both of nickel, cobalt, and manganese (or a feed mixture as described above) is added to an aqueous solution, particularly in a first mixer under stirring. The solution (including entrained solids) exits the first mixer via a liquid outlet and enters a first settling tank via a liquid inlet. The first settling tank includes at least one upper outlet in the upper part of the container to provide a liquid outlet and a lower outlet in the lower part of the container to provide a settled solids outlet. The liquid may exit the first settling tank via the upper outlet according to step (ii) of the method of the first state sample, or liquid impurities in the solution may be removed (as another part of step (i) of the method of the first state sample). The liquid / solid exiting the first settling tank via the lower outlet may flow into a second mixer via a second mixer inlet. A reducing agent or oxidizing agent and a leaching agent may be added to the second mixer. In some cases, there is no settling tank and the solution is taken directly to a filter. The second mixer may be stirred. The solution (including entrained solids) exits the second mixer via the liquid outlet and enters the second settling tank via the liquid inlet. The second settling tank includes at least one upper outlet in the upper part of the container to provide a liquid outlet and a lower outlet in the lower part of the container to provide a settled solids outlet. Liquid exiting the second settling tank via the upper outlet may flow to the inlet of the first mixer. Liquid / solid exiting the second settling tank via the lower outlet may be discarded, for example, after passing through a screw press. The advantage of this configuration is that it minimizes the amount of residual acid and reducing or oxidizing agents in the solution, in which nickel, cobalt, and manganese co-precipitate. Furthermore, the amount of iron (and other impurities, such as copper and aluminum) in the first mixer can be minimized by maintaining appropriate conditions. In some embodiments, the method may include the use of three or more mixers (or reactors). The method may include the step of controlling the amount of reagent added to any of these mixers.

[0111] The method may include the step of adding one or more of cobalt, manganese, and nickel to a feed solution or leaching solution to adjust the molar ratio of nickel, cobalt, and manganese to a desired molar ratio. Suitable desired molar ratios may include 1:1:1 nickel:cobalt:manganese, or 6:2:2 nickel:cobalt:manganese, or 8:1:1 nickel:cobalt:manganese. In some embodiments, the required molar ratio may include 1:1:1 nickel:cobalt:manganese, 2:1:1 nickel:cobalt:manganese, 3:1:1 nickel:cobalt:manganese, 4:1:1 nickel:cobalt:manganese, 5:1:1 nickel:cobalt:manganese, 6:1:1 nickel:cobalt:manganese, 7:1:1 nickel:cobalt:manganese, 8:1:1 nickel:cobalt:manganese, 9:1:1 nickel:cobalt:manganese, 10:1:1 nickel:cobalt:manganese, 5:3:2 nickel:cobalt:manganese, 9:0.5:0.5 nickel:cobalt:manganese, or 83:5:12 nickel:cobalt:manganese. The required molar ratio of nickel to manganese may include 1:1 nickel:manganese, or 6:2 nickel:manganese, or 8:1 nickel:manganese. In some embodiments, the required molar ratio may include 1:1 nickel:manganese, 2:1 nickel:manganese, 3:1 nickel:manganese, 4:1 nickel:manganese, 5:1 nickel:manganese, 6:1 nickel:manganese, 7:1 nickel:manganese, 8:1 nickel:manganese, 9:1 nickel:manganese, 10:1 nickel:manganese, 5:3 nickel:manganese, or 9:0.5 nickel:manganese. The required molar ratio of cobalt:manganese may include 1:1 cobalt:manganese, or 6:2 cobalt:manganese, or 8:1 cobalt:manganese. In some embodiments, the required molar ratio may include 1:1 cobalt:manganese, 2:1 cobalt:manganese, 3:1 cobalt:manganese, 4:1 cobalt:manganese, 5:1 cobalt:manganese, 6:1 cobalt:manganese, 7:1 cobalt:manganese, 8:1 cobalt:manganese, 9:1 cobalt:manganese, 10:1 cobalt:manganese, 5:3 cobalt:manganese, or 9:0.5 cobalt:manganese. The required molar ratio of nickel:cobalt may include 1:1 nickel:cobalt, or 6:2 nickel:cobalt, or 8:1 nickel:cobalt. In some embodiments, the required molar ratio may include 1:1 nickel:cobalt, 2:1 nickel:cobalt, 3:1 nickel:cobalt, 4:1 nickel:cobalt, 5:1 nickel:cobalt, 6:1 nickel:cobalt, 7:1 nickel:cobalt, 8:1 nickel:cobalt, 9:1 nickel:cobalt, 10:1 nickel:cobalt, 5:3 nickel:cobalt, or 9:0.5 nickel:cobalt. In one embodiment, the previously mentioned molar ratio may be the nickel:cobalt:manganese ratio, or the nickel:cobalt:manganese ratio, or the cobalt:manganese ratio, in the coprecipitate. Not all nickel, cobalt, or manganese in the feed solution will precipitate. Those skilled in the art will be able to select a suitable ratio based on the desired application and the required nickel:cobalt:manganese ratio in the final material (e.g., cathode material).

[0112] One or more of the cobalt, manganese, and nickel added to the solution may be in any suitable form. One or more cobalt-containing, manganese-containing, or nickel-containing compounds may be added to the feed solution. For example, the added cobalt, manganese, and nickel may be in the form of one or more sulfates, hydroxides, or carbonates, or mixtures thereof; particularly CoSO4, NiSO4, and / or MnSO4. In some cases, the feed mixture may be produced by combining separate feed mixtures, each independently an oxidizing feed, a reducing feed, or an unoxidized feed, to produce a composite feed for use in the methods described herein. In other cases, more than one feed mixture (each independently an oxidizing feed, a reducing feed, or an unoxidized feed) may be used to produce more than one leaching solution by the methods described herein, and these more than one leaching solutions may subsequently be combined in any suitable proportion to provide a composite leaching solution. In one embodiment, metals other than Ni, Co, and Mn (in any suitable form) may be added to the leaching solution or aqueous feed solution. This can help produce coprecipitates with the other metals present.

[0113] Step (ii) of the method produces a co-precipitate comprising at least two metals selected from nickel, cobalt, and manganese. In one embodiment, the at least two metals selected from nickel, cobalt, and manganese are all nickel, cobalt, and manganese.

[0114] In one embodiment, more than 1%, or more than 10%, or more than 20%, or more than 50%, or more than 60%, or more than 80%, or more than 90%, or more than 99% of at least one metal (especially at least two metals, and more particularly all of nickel, cobalt, and manganese) in the coprecipitate originates from the feed mixture (which has been leached). In one embodiment, the feed mixture may be a plurality of pre-combined feed mixtures. In one embodiment, each of the plurality of feed mixtures may be derived from a different source.

[0115] The pH of the coprecipitation step is about 6.2 to about 11, or about 6.2 to about 10.5, or about 6.2 to about 10, or about 6.2 to about 9.2, 6.2 to 9, 6.2 to 8, 6.2 to 7, 6.2 to 6.5, 6.5 to 9.2, 7 to 9.2, 8 to 9.2, 9 to 9.2, 6.5 to 9, 6.5 to 8, 7 to 9, or 7 to 8, for example, about 6.2, 6.3, 6.4, 6.5, 7, 7.5, 8, 8.5, 8.6, 8.7, 8.8, 8.9, 9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, or 10. A pH of about 9 to 9.2 may be advantageous if the feed solution from which at least two metals are coprecipitated is relatively pure.

[0116] The inventors have advantageously discovered that, although the choice of pH depends on the type and concentration of impurities present, a pH range between about 7.0 and about 8.6, or between 6.2 and 8.6, can induce less co-precipitation or include fewer undesirable impurities, such as magnesium and / or calcium salts, compared to using a higher pH range. For example, at pH above about 8.5, magnesium will typically begin to precipitate from solution as hydroxides or oxides, while at pH above about 10.0, calcium will typically begin to precipitate from solution as hydroxides or oxides (however, complete precipitation of these impurities will not occur until the higher pH is reached, and partial precipitation of these elements may occur at lower pH, depending on the precipitation method). Therefore, co-precipitation can even occur at pH at which some impurities begin to precipitate. However, the relative amount of impurity precipitation can be controlled so as not to adversely affect the performance of the battery pack materials or to achieve the desired amount of impurities or the desired battery pack material performance in the co-precipitation.

[0117] Any suitable reagent (such as a base) may be used to adjust the pH. Exemplary reagents (or bases) may include alkali metal or alkaline earth metal hydroxides, such as sodium hydroxide. However, bases may be materials containing nickel, cobalt, and / or manganese, such as fresh solids (such as hydroxides, carbonates, or hydroxycarbonates), or nickel, cobalt, and manganese precipitates (such as those produced by step (ii), especially hydroxide precipitates).

[0118] Step (ii) can be performed at any suitable temperature or pressure. It can be performed at the temperature and pressure where the feed solution is in liquid form. In one embodiment, step (ii) is performed at about 15 to about 25°C, for example, at about room temperature. In one embodiment, step (ii) is performed at a temperature below about 100°C or below about 90, 85, 80, 70, 60, or 50°C. In another embodiment, step (ii) is performed at a temperature greater than about 30°C or greater than about 35, 40, 45, 50, 55, 60, 65, 70, 75, or 80°C. In one embodiment, step (ii) is performed at a temperature between about 25°C and about 100°C, or between about 40°C and 95°C, 50°C and 95°C, 60°C and 90°C, or 70°C and 90°C. In one embodiment, step (ii) is performed at a temperature of about 80°C. In another embodiment, step (ii) is performed at atmospheric pressure.

[0119] Step (ii) can be carried out with any suitable base. In one embodiment, the base may be a carbonate, bicarbonate, hydroxide, ammonia, or a mixture thereof. It may be ammonia. Suitable carbonates may include carbonates selected from the group consisting of: ammonium carbonate, sodium carbonate, potassium carbonate, lithium carbonate, or a mixture thereof. Suitable bicarbonates may be selected from the group consisting of: sodium bicarbonate and ammonium bicarbonate, or a mixture thereof. A suitable bicarbonate is ammonium bicarbonate. A suitable hydroxide may be ammonium hydroxide or sodium hydroxide.

[0120] At least two metals may be co-precipitated in any suitable form, such as in the form of oxides, hydroxides, carbonates and / or hydroxycarbonates.

[0121] At least two metals may be entirely nickel, cobalt, and manganese. These metals may be co-precipitated in any suitable molar ratio. Exemplary molar ratios may include 1:1:1 nickel:cobalt:manganese, or 6:2:2 nickel:cobalt:manganese, or 8:1:1 nickel:cobalt:manganese. In some embodiments, molar ratios may include 1:1:1 nickel:cobalt:manganese, 2:1:1 nickel:cobalt:manganese, 3:1:1 nickel:cobalt:manganese, 4:1:1 nickel:cobalt:manganese, 5:1:1 nickel:cobalt:manganese, 6:1:1 nickel:cobalt:manganese, 7:1:1 nickel:cobalt:manganese, 8:1:1 nickel:cobalt:manganese, 9:1:1 nickel:cobalt:manganese, 10:1:1 nickel:cobalt:manganese, or 9:0.5:0.5 nickel:cobalt:manganese.

[0122] Step (ii) may include separating the coprecipitate from the supernatant. Such separation may include one or more of decantation or filtration. Separation may include resuspending the coprecipitate in the decanted or filtered solution. Separation may include washing the decanted or filtered solid with a solution.

[0123] In one embodiment of the method of the first state sample, step (ii) is followed by washing the coprecipitate (especially nickel, cobalt, and manganese). This dissolves and / or removes impurities present in the initially formed coprecipitate. Washing can be performed in at least one washing step (or at least two washing steps), such as at least one resuspension washing step. Impurities in the initially formed coprecipitate may be present by means of association or adsorption and may require washing to remove such impurities, even if they do not substantially precipitate. In one embodiment, washing utilizes an aqueous solution (especially a relatively pure aqueous solution, such as distilled water), or may utilize a solution containing a base, acid, or basic reagent (especially an aqueous solution) (this can achieve the desired removal of impurity elements). The washing steps may include a plurality of washing steps. The plurality of washing steps may utilize different washing solutions. This can help remove different impurities. These washing solutions may remove contaminated solutions containing solids, or may react with solids to remove partially coprecipitated impurities, or both.

[0124] In one embodiment of the method, step (ii) is followed by mixing the co-precipitate (or precipitated nickel, cobalt, and manganese) with lithium. This may then be followed by calcining the lithium and the co-precipitate (or nickel, cobalt, and manganese). This can form a cathode active material (CAM). The co-precipitate can provide NMC material for use as a cathode active material (CAM) in new battery packs.

[0125] In one embodiment, the calcined lithiation coprecipitate can provide battery pack performance greater than 10 mAh / g, or greater than 20, 50, 70, 100, 120, 130, 140, 150, 160, 170, 180, 190, or 200 mAh / g. In this embodiment, electrochemical performance is defined by the first cycle capacity measured in a coin half-cell battery test conducted at a charge / discharge rate of 0.2 C within a voltage range of 3.0–4.4 V.

[0126] In another embodiment of the method of the first state sample, after step (ii), residual nickel and / or cobalt and / or manganese in the supernatant may be removed by precipitation and / or ion exchange.

[0127] Before or after the step of removing one or more impurities, the feed solution may contain one or more impurities. These impurities may be selected from Ca²⁺, Mg²⁺, Li⁺, Na⁺, K⁺, NH₄⁺, S, F⁻, and Cl⁻; particularly from Ca²⁺, Mg²⁺, Li⁺, Na⁺, K⁺, S, F⁻, and Cl⁻. Other impurities, such as iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, zirconium, and titanium, may also be present or alternatively present. The impurities in the feed solution may be present at a level at which, if included in the final coprecipitate, they will adversely affect the performance of the CAM prepared from it.

[0128] In one embodiment, the method described herein involves treating a feed solution containing at least two metals selected from Ni, Co, and Mn, if necessary, to remove some impurities, and, where appropriate, mixing the resulting solution with a sufficient amount of other solutions containing Ni and / or Co and / or Mn to achieve a desired Ni:Mn:Co ratio (or Ni:Co, Ni:Mn, or Co:Mn ratio) in solution. Where appropriate, in the presence of any residual impurities, coprecipitates are selectively precipitated from the solution such that the filtered, washed, and cleaned coprecipitates are appropriately pure and possess suitable properties with respect to impurities, enabling sufficient performance as a battery pack material after further processing.

[0129] In one embodiment, the precipitation of the coprecipitate is carried out in the presence of certain impurities. That is, some impurities present in the feed solution (or the solid material used to generate the feed solution) may not be removed from the solution prior to the precipitation step. The amount of such impurities appearing in the coprecipitate can be controlled by controlling the upstream impurity removal or separation steps and by controlling the precipitation step and subsequent precursor washing and cleaning steps, so that such impurities do not appear in the initially formed coprecipitate, or appear in the initially formed coprecipitate but are subsequently washed out or removed, or appear in the final coprecipitate at a concentration and form sufficient to achieve the performance of a precursor material intended for use as a cathode material in a battery pack. It should be understood that in this context, "initially formed coprecipitate" refers to the material initially precipitated from the aqueous feed solution after pH adjustment, and "final coprecipitate" refers to the solid material produced from the initially formed coprecipitate after any subsequent purification steps (e.g., washing, drying) as described herein. The final coprecipitate can then be used as a precursor material for manufacturing lithium-ion battery packs. In one embodiment, the coprecipitate as described herein is the initially formed coprecipitate.

[0130] A common or standard method for producing precursor materials involves starting with extremely high-purity Ni, Co, or Mn materials, such as sulfates, metals, hydroxides, oxides, and carbonates, and dissolving this material in a sulfate solution. The solutions of the three elements are then mixed together to achieve the desired Ni:Co:Mn ratio. The resulting solution contains no or negligible amounts of any impurity elements. This NiMnCo solution can also be mixed with some ammonia-containing solutions, as ammonia can act as a binding agent that advantageously mediates the precipitation reaction. The precursor is then precipitated using sodium hydroxide or sodium carbonate, or a combination of sodium hydroxide or ammonium hydroxide with carbonates. This causes the precipitation of a mixture containing Ni / Co / Mn oxides or carbonates, or a mixture of oxides and carbonates. The precipitated material is then filtered and washed with water. Sometimes, it is further washed or mixed with an additional sodium carbonate solution, which will extract any residual sulfate ions. In this way, typical precursor materials with suitable battery pack performance are produced from very high-purity feedstocks.

[0131] The main reason for this standard method is that it is believed that the production of battery pack precursor materials requires extremely high purity feedstock in order to avoid any impurity elements contaminating the battery pack materials, which would have an adverse effect on battery pack performance.

[0132] However, the inventors have unexpectedly discovered that some elements can be present during the precursor production process without adversely affecting the battery pack material performance. This means it is possible to use feed and processes that introduce such elements into the solution without contaminating or adversely affecting the precursor product. In some embodiments, at least one impurity can be added to the aqueous feed solution prior to co-precipitation. This can facilitate the co-precipitation step (e.g., when at least one impurity comprises sodium and potassium salts).

[0133] The materials used to prepare the aqueous feed solution in the method of the present invention may include the materials discussed in the co-applications mentioned above. They may also include Ni, Co, or Mn materials that do not contain a large amount of more than one of Ni, Co, or Mn, although they may include one or more impurities. In one embodiment, at least one of the Ni, Co, or Mn materials may include at least one impurity. Therefore, the selective leaching conditions discussed in the co-applications mentioned above also apply here to any of the individual materials used. These impurities only need to be removed from the aqueous feed solution before the step of adjusting the pH to a concentration such that sufficient performance of the battery pack materials is achieved by the final co-precipitate. In some cases, the presence of some of these impurities can actually improve the performance of the battery pack materials.

[0134] Alkali metals such as Li(I), Na(I), and K(I) are generally highly soluble in acidic solutions and do not exhibit stable or oxidative precipitation behavior, and are therefore typically dissolved under leaching conditions used to prepare aqueous feed solutions. Alkali earth metals such as Mg(II) generally exhibit similar behavior. Alkali earth metals such as Ca(II) are also generally soluble, however, their concentration in sulfuric acid is limited to relatively low levels due to the solubility of various sulfate compounds. Therefore, these elements can be present in feed solutions. However, alkali metals such as Li, Na, and K are generally soluble in aqueous solutions with a pH of at most greater than 12, and therefore generally do not precipitate or co-precipitate significantly. Alkali earth metals such as Mg can precipitate as hydroxides or carbonates at about pH 8-9. Alkali earth metals such as Ca can precipitate as carbonates at about pH 8-9 and as hydroxides at about pH 9-10. Therefore, during the coprecipitation step, careful control of pH, and possible variables such as the addition of alkali, the initial and final concentrations of elements in solution (and other variables that can affect this precipitation behavior, such as temperature, reagent addition rate, reagent concentration, and washing conditions), and the choice of precipitating reagent may allow control of the behavior of these elements during the formation of the coprecipitate (or, if multiple precipitation and / or multiple washing steps, the final coprecipitate). Regardless of whether Li, Na, and K are soluble at pH values ​​higher than the pH at which the coprecipitate precipitates, these elements can still substantially contaminate the solid product without selective precipitation and washing, especially if the amount of these elements in the supernatant after coprecipitate precipitation is higher than if only reagents were added for the self-precipitate precipitation.

[0135] This means that any Ni or Co or Mn-containing material that also contains significant Li, Na, K, Mg or Ca impurities can be used as feed for preparing the feed solution, and that these impurities are not removed solely by selective dissolution and impurity removal and / or separation steps. Any adverse effects of these elements on battery pack performance can be avoided by methods as described herein, which may involve controlling precursor precipitation, washing and cleaning processes.

[0136] Step (ii) of the method described herein may be carried out using any one or more of, for example, sodium carbonate, sodium hydroxide, potassium carbonate, potassium hydroxide, lithium carbonate, lithium hydroxide, ammonia, ammonium carbonate and ammonium hydroxide as a precipitating agent (e.g., to adjust the pH of the feed solution).

[0137] Step (ii) of the method described herein can be performed for any suitable time. For example, step (ii) can be performed for at least 1 hour, 2 hours, 4 hours, 8 hours, 16 hours, 24 hours, 36 hours, or 48 hours.

[0138] Precursor materials can be precipitated at a target Ni:Mn:Co ratio using careful control of the concentrations of Ni, Co, and / or Mn in the feed solution, the addition rates of Ni, Co, and Mn solutions, the pH adjustment rate, temperature, reaction time, aging time, and many other factors (such as the presence of fault ions, such as ammonia) to produce an initial coprecipitate, which can then be filtered and washed to obtain a battery pack precursor material with sufficient performance. After the formation of the initial coprecipitate, the environment containing at least two metals can be controlled to minimize or mitigate, or maximize, any oxidation of at least two metals. Such control may include controlling the atmosphere surrounding the at least two metals, the coprecipitate, the initial coprecipitate, or the final coprecipitate. Controlling the atmosphere may include controlling the oxygen concentration in the atmosphere or any gas phase, and the pressure in the atmosphere or any gas phase.

[0139] It is generally accepted that, for suitable coprecipitate cathode active materials (precursor materials) in the form of hydroxides, the amount of nickel, manganese, and / or cobalt in the coprecipitate, on a dry solids basis, should preferably be at least about 60% of the material. The remaining approximately 40% may be oxides, hydroxides, or carbonates. Within this 60% of the material, impurity limits are typically specified as 3000-4000 ppm for anionic species such as SO₄²⁻, F⁻, and Cl⁻ (excluding the aforementioned oxides, hydroxides, or carbonates); 300 ppm for alkali metals and alkaline earth metals (except lithium) (or for alkaline earth metals); and 50 ppm for metals and metalloids. Therefore, anions (especially excluding hydroxides, oxides, and carbonates) can have a molar ratio (or mass ratio) of approximately 200:1 for NMC to impurities. 300 ppm of Ca and Mg (or Ca, Mg, Na and K) provides a solid molar ratio (or mass ratio) of approximately 2000:1 for NMC to impurities, and for example 50 ppm of Fe produces a solid molar ratio (or mass ratio) of approximately 12,000:1 for NMC to impurities.

[0140] The total amount of nickel, manganese and / or cobalt in the aqueous feed solution may be at least 1 g / L, or at least 5 g / L, or at least 8 g / L, or at least 10 g / L, or at least 15 g / L, or at least 20 g / L, or at least 30 g / L, or at least 50 g / L, or at least 70 g / L, or at least 90 g / L, or at least 120 g / L, or at least 150 g / L, or at least 200 g / L.

[0141] In one embodiment, the amount of at least two metals in the coprecipitate is controlled to be less than 100% of the amount of at least two metals in the aqueous feed solution. In another embodiment, the amount of at least two metals in the coprecipitate is controlled to be less than 99%, less than 95%, less than 90%, less than 80%, less than 70%, less than 50%, or less than 20% of the amount of at least two metals in the aqueous feed solution. The amounts of nickel, manganese, and cobalt in the coprecipitate relative to their amounts in the aqueous feed solution may be different percentages or the same percentages.

[0142] In one embodiment, the supernatant in step (ii) contains less than 1 mg / L, or more than 1 mg / L, or more than 5, 10, 100, 200, 500 or 1000 mg / L of Ni, Co or Mn.

[0143] In one embodiment, the concentration of an alkali metal (such as Na, Li, K) (or at least one alkali metal) in the aqueous feed solution is less than or equal to 100,000 ppm, or less than or equal to 80,000 ppm, or less than or equal to 60,000 ppm, or less than or equal to 50,000 ppm, or less than or equal to 40,000 ppm, or less than or equal to 30,000 ppm, or less than or equal to 20,000 ppm, or less than or equal to 15,000 ppm, or less than or equal to 10,000 ppm, or less than or equal to 7,000 ppm, or less than or equal to 5,000 ppm, or less than or equal to 4,000 ppm, or less than or equal to 3,000 ppm, or less than or equal to 2,500 ppm, or less than or equal to 2,000 ppm. In another embodiment, the molar ratio of at least two metals to alkali metal impurities (or at least one alkali metal impurity) in the aqueous feed solution may be greater than about 1:50, or greater than about 1:10, or greater than about 1:5, or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or greater than about 120:1, or greater than about 150:1, or greater than about 180:1 or greater than about 200:1. In another embodiment, the molar ratio of at least two metals to alkali metal impurities (or at least one alkali metal impurity) in the aqueous feed solution may be less than about 1:1, or less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1, or less than about 200:1. In another embodiment, the molar ratio of at least two metals to alkali metal impurities (or at least one alkali metal impurity) in the aqueous feed solution may be from about 1:10 to 23,000:1, or from about 1:10 to 100,000,000:1, or from about 1:10 to 300,000,000:1. In another embodiment, the molar ratio of at least two metals to alkali metal impurities (or at least one alkali metal impurity) in the aqueous feed solution may be from about 1:50 to 23,000:1, or from about 1:50 to 100,000,000:1, or from about 1:50 to 300,000,000:1. In one embodiment, the alkali metal impurities are not derived from the precipitating reagent.

[0144] In one embodiment, the percentage of alkali metals present in the aqueous feed solution that cause co-precipitates is less than 100%, less than 99%, less than 90%, less than 50%, less than 20%, or less than 1%.

[0145] In another embodiment, the coprecipitate contains less than 10 ppm of an alkali metal in dry solid form, or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or less than 5000 ppm, or less than 20000 ppm.

[0146] In one embodiment, the concentration of anionic species impurities (such as F- and Cl-, but especially excluding the aforementioned oxides, hydroxides, sulfates, or carbonates) (or at least one anionic species impurity) in the aqueous feed solution is less than or equal to 100,000 ppm, or less than or equal to 80,000 ppm, or less than or equal to 60,000 ppm, or less than or equal to 50,000 ppm, or less than or equal to 40,000 ppm, or less than or equal to 30,000 ppm, or less than or equal to 20,000 ppm, or less than or equal to 10,000 ppm, or less than or equal to 5,000 ppm, or less than or equal to 4,000 ppm, especially less than or equal to 3,000 ppm, or less than or equal to 2,500 ppm, or less than or equal to 2,000 ppm. In another embodiment, the molar ratio of at least two metals to anionic species impurities (or at least one anionic species impurity) in the aqueous feed solution may be greater than about 1:10, or greater than about 1:5, or greater than about 1:1, or greater than about 5:1, or greater than about 10:1, or greater than about 20:1, or greater than about 50:1, or greater than about 80:1, or greater than about 100:1, or greater than about 120:1, or greater than about 150:1, or greater than about 180:1 or greater than about 200:1. In another embodiment, the molar ratio of at least two metals to anionic species impurities (or at least one anionic species impurity) in the aqueous feed solution may be less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1 or less than about 200:1.

[0147] In one embodiment, the percentage of anionic species present in the aqueous feed solution that cause coprecipitation is less than 100%, or less than 99%, or less than 90%, or less than 50%, or less than 20%, or less than 1%.

[0148] In another embodiment, the coprecipitate contains less than 10 ppm of anions in dry solid form (excluding hydroxide, oxygen, carbonate or bicarbonate anions), or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or less than 5000 ppm, or less than 20000 ppm.

[0149] Not wanting to be bound by theory, the inventors believe that, due to phenomena such as liquid entrainment and atomic substitution, some anions (specifically, F-, PO43-, Cl-, SO42-, and NO3-) can exist in the coprecipitate or supernatant after physical separation. The inventors have advantageously discovered that such anionic impurities can be largely controlled using specified methods. These anions can be removed by washing or re-slurrying the coprecipitate to the desired extent or by reacting with the washing or re-slurrying solution.

[0150] In another embodiment, the concentration of alkaline earth metal impurities (such as CA and Mg) (or at least one alkaline earth metal impurity) in the aqueous feed solution is less than 900,000 ppm, or less than 700,000 ppm, or less than 500,000 ppm, or less than 200,000 ppm, or less than 100,000 ppm, or less than 50,000 ppm, or less than 40,000 ppm, or less than 30,000 ppm, or less than 20,000 ppm, or less than 10,000 ppm, or less than 5,000 ppm, or less than 1,000 ppm, or less than 800 ppm, or less than 600 ppm, or less than 500 ppm, or less than 400 ppm, or less than 300 ppm, or less than 250 ppm, or less than 200 ppm, or less than 150 ppm, or less than 100 ppm, or less than 50 ppm, or less than 200 ppm. ppm, or less than 10 ppm, or less than 5 ppm, or less than 1 ppm, or less than 100 ppb, or less than 10 ppb. In another embodiment, the concentration of alkaline earth metal impurities (such as CA and Mg) (or at least one alkaline earth metal impurity) in the aqueous feed solution is greater than 900,000 ppm, or greater than 700,000 ppm, or greater than 500,000 ppm, or greater than 200,000 ppm, or greater than 100,000 ppm, or greater than 50,000 ppm, or greater than 40,000 ppm, or greater than 30,000 ppm, or greater than 20,000 ppm, or greater than 10,000 ppm, or greater than 5,000 ppm, or greater than 1,000 ppm, or greater than 800 ppm, or greater than 600 ppm, or greater than 500 ppm, or greater than 400 ppm, or greater than 300 ppm, or greater than 250 ppm, or greater than 200 ppm, or greater than 150 ppm, or greater than 100 ppm, or greater than 500 ppm. ppm, or greater than 20 ppm, or greater than 10 ppm, or greater than 5 ppm, or greater than 1 ppm, or greater than 100 ppb, or greater than 10 ppb. In another embodiment, the molar ratio of at least two metals to alkaline earth metal impurities (or at least one alkaline earth metal impurity) in the aqueous feed solution is greater than about 1:50, or greater than about 1:20, or greater than about 1:10, or greater than about 1:1, or greater than about 10:1, or greater than about 50:1, or greater than about 100:1, or greater than about 200:1, or 500:1, or greater than about 1000:1, or greater than about 1500:1, or greater than about 2000:1, or greater than about 5,000:1 or greater than about 10,000:1.In one embodiment, the molar ratio of at least two metals to alkaline earth metal impurities (or at least one alkaline earth metal impurity) in the aqueous feed solution is about 300,000,000:1 to about 1:10; or greater than about 1:10, or greater than about 1:1. In one embodiment, the molar ratio of at least two metals to alkaline earth metal impurities (or at least one alkaline earth metal impurity) in the aqueous feed solution is less than 1:50, or less than 1:20, or less than 1:10, or less than 1:5, or less than 1:1, or less than about 5:1, or less than about 10:1, or less than about 20:1, or less than about 50:1, or less than about 80:1, or less than about 100:1, or less than about 120:1, or less than about 150:1, or less than about 180:1, or less than about 200:1, or less than about 500:1, or less than about 1000:1, or less than about 2000:1, or less than about 5000:1, or less than about 10,000:1. In one embodiment, the ratio (by weight) of at least two metals to alkaline earth metals in the aqueous feed solution is less than 10,000:1. In one embodiment, the ratio of at least two metals in the aqueous feed solution to calcium (by weight) is less than 10,000:1. In another embodiment, the ratio of at least two metals in the aqueous feed solution to magnesium (by weight) is less than 10,000:1. In one embodiment, the ratio of at least two metals in the aqueous feed solution to metals other than nickel, cobalt, manganese, and alkaline earth metals and / or alkali metals (by weight) is less than 6,000:1.

[0151] In one embodiment, the percentage of alkaline earth metal species present in the aqueous feed solution and reportedly in the coprecipitate is less than 100%, or less than 99%, or less than 90%, or less than 70%, or less than 50%, or less than 10%, or less than 1%, or less than 0.5%, or less than 0.1%.

[0152] In another embodiment, the coprecipitate contains less than 10 ppm of alkaline earth metal in dry solid form, or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or less than 5000 ppm, or less than 10000 ppm.

[0153] In another embodiment, the concentration of metal and metalloid impurities (or at least one metal or metalloid impurity) in the aqueous feed solution is less than 250 ppm, particularly less than 50 ppm. In another embodiment, the concentration of metal and metalloid impurities (or at least one metal or metalloid impurity) in the aqueous feed solution is greater than 1 ppb, particularly greater than 100 ppb, or greater than 1 mg / L, or greater than 5 mg / L, or greater than 10 mg / L, or greater than 20 mg / L, or greater than 50 mg / L. Exemplary metal and metalloid impurities may be particularly selected from the group consisting of: iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, zirconium, scandium, and titanium. In one embodiment, the molar ratio of at least two metals to metal and metalloid impurities (or at least one metal or metalloid impurity) is less than 50:1, or less than 100:1, or less than 500:1, or less than 1,000:1, or less than 5,000:1, or less than 10,000:1, or less than 20,000:1, or less than 40,000:1, or less than 60,000:1, or less than 80,000:1, or less than 100,000:1, or less than 500,000:1. In one embodiment, the molar ratio of at least two metals to Fe impurities is from about 300,000,000:1 to about 10,000:1; or greater than about 10,000:1, or greater than 12,000:1. In one embodiment, the molar ratio of at least two metals to the Fe impurity is less than 10,000:1, or less than 20,000:1, or less than 100,000:1, or less than 500,000:1, or less than 1,000,000:1. In one embodiment, the molar ratio of at least two metals to the Al impurity is about 300,000,000:1 to about 10,000:1; or greater than about 10,000:1, or greater than 12,000:1. In one embodiment, the molar ratio of at least two metals to the Al impurity is less than 10,000:1, or less than 20,000:1, or less than 100,000:1.

[0154] In one embodiment, the ratio of at least two metals in the aqueous feed solution to iron (by weight) is less than 16,000:1. In one embodiment, the ratio of at least two metals in the aqueous feed solution to copper (by weight) is less than 6,000:1. In one embodiment, the ratio of at least two metals in the aqueous feed solution to aluminum (by weight) is less than 10,000:1. In one embodiment, the ratio of at least two metals in the aqueous feed solution to niobium (by weight) is less than 500,000:1. In one embodiment, the ratio of at least two metals in the aqueous feed solution to tungsten (by weight) is less than 500,000:1. In one embodiment, the ratio of at least two metals in the aqueous feed solution to zirconium (by weight) is less than 500,000:1.

[0155] In one embodiment, the percentage of metal and metalloid species present in the aqueous feed solution that cause coprecipitation is less than 90%, or less than 10%, or less than 1%.

[0156] In another embodiment, the coprecipitate contains less than 10 ppm of dry solid metal and metalloid species, or less than 250 ppm, or less than 500 ppm, or less than 1000 ppm, or less than 2000 ppm, or less than 5000 ppm, or less than 10,000 ppm.

[0157] However, the inventors have found that the above specifications may be somewhat arbitrary in some cases. For example, at most 500 or 1000 ppm of Ca and Mg in the final coprecipitate does not appear to have a significant impact on the battery pack material performance. Therefore, it is likely that a lower proportion of these elements is acceptable. It is believed that a calcium content of at least two metals:Ca of up to 1000:1 can exist in the coprecipitate without adverse effects.

[0158] As described elsewhere in this document, when using the method of the present invention to produce the final coprecipitate, it is possible to largely avoid the precipitation of many of these elements, while for other elements, a certain degree of coprecipitation is relatively unavoidable. However, in the latter case, the coprecipitation of impurities may have a minimal impact on the performance of the final coprecipitate, or provide acceptable performance when used in battery pack materials.

[0159] Using Mg as an example, it is possible to achieve Mg coprecipitation at 100%, close to 100%, less than 100%, less than 50%, and as low as substantially less than 10%. Assuming 1% Mg precipitation from the solution and precipitation of Ni, Co, and Mn, a feed solution with a ratio of at least two metals to Mg of 10:1 will make it possible to achieve a coprecipitate with a ratio of at least two metals to Mg of 1000:1.

[0160] The inventors have discovered that even with relatively small amounts of Mg coprecipitation, it is possible and has been demonstrated that feed solutions containing a 1:17 ratio of two metals:Mg can be used to produce acceptable coprecipitates. Therefore, feed solutions having a ratio of at least two metals:Mg of up to 1:10 or even 1:50 can provide acceptable coprecipitates at the desired Mg ratio. Feed solutions having a ratio of at least two metals:Mg of up to 1:1 or even 1:10 can also provide acceptable coprecipitates. Similar ratios for Ca are also achievable.

[0161] For other elements such as Fe, coprecipitation can be 100%, close to 100%, or less than 100%. With 100% Fe coprecipitation and 100% precipitation of at least two metals, to achieve a 12,000:1 ratio of at least two metals to Fe in the initial coprecipitate (roughly equivalent to a target concentration of 50 ppm in the final coprecipitate), a 12,000:1 ratio of at least two metals to Fe in the solution will be the upper limit. In this case, the method can still allow the aqueous feed solution to be processed to produce a coprecipitate. However, if less than 100% Fe coprecipitation is performed, the ratio of at least two metals to Fe in the aqueous feed solution can be less than 12,000:1, and less than 50 ppm Fe can be achieved in the coprecipitate. It is also possible to tolerate more than 50 ppm Fe or other elements in the final coprecipitate without significantly affecting the battery pack material performance.

[0162] Conversely, a feed solution free of impurities is practically impossible to readily obtain or use in this invention. The actual minimum value of the individual or combination of impurities present may be about 2 ppb, or about 3, 5, 10, 50, 100, 200 or 500 ppb, or about 1, 2, 5, 10, 50, 100, 200, 500, 1000, 2000, 5000 or 10000 ppm.

[0163] In one embodiment, the amount of at least one impurity in the coprecipitate relative to at least two metals is less than the amount of at least one impurity in the aqueous feed solution relative to at least two metals. In one embodiment, the coprecipitate contains less than 100% of at least one impurity in the aqueous feed solution, particularly less than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% of at least one impurity in the aqueous feed solution. In one embodiment, the coprecipitate contains less than 100% of alkali metals and anions in the aqueous feed solution, particularly less than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% of alkali metals and anions in the aqueous feed solution. In one embodiment, the coprecipitate contains less than 100% of alkaline earth metals in the aqueous feed solution, particularly less than 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, or 10% of alkaline earth metals in the aqueous feed solution. In one embodiment, the coprecipitate contains less than 100% alkali metal and ionic species in the aqueous feed solution; and the supernatant contains at least 0.1% alkaline earth metal, less than 100% alkali metal and ionic species, and less than 100% metals other than alkali metal and alkaline earth metal in the aqueous feed solution.

[0164] In one embodiment, at least 1% and at most 100% of the nickel, cobalt and / or manganese are derived from an impure feed source (wherein the ratio of nickel, cobalt and / or manganese to impurities is less than 0.01:1, less than 0.1:1, less than 1:1, less than 10:1, less than 100:1, less than 500:1, less than 1000:1, less than 5000:1, less than 10,000:1, less than 50,000:1, less than 200,000:1 or less than 500,000:1).

[0165] The inventors have advantageously discovered that the content of beneficial impurities in the final product can be controlled by processing an impure solution. In prior art methods, such beneficial impurities (such as Mg or Al) can be added separately as dopants. The method of the present invention allows this cost to be avoided while still producing acceptable coprecipitates. This allows for a wide variety of feeds to be used in these methods. This is particularly important in cases where certain feeds contain impurities that can also be used as dopants (e.g., aluminum and magnesium); or in cases where recycle battery pack feeds are used as recycle materials that may contain impurities that can also be used as dopants, and the described method allows such impurities present in the feed to be controlled such that they are reported at the desired concentrations in the supernatant and coprecipitate. In all such cases, a substantial portion of the desired dopant element can be derived from a feed containing at least one metal and at least one impurity.

[0166] As previously discussed, a typical prior art process dissolves individual high-purity nickel sulfate, cobalt sulfate, and manganese sulfate feeds in a solution at specific ratios and purities, followed by co-precipitation of the solution. In such processes, these salt feeds may contain, for example, 5 ppm or less of impurities. Examples of two specifications required for preparing NMC materials using nickel sulfate hexahydrate are shown in the table below. Given the extremely low permissible impurity concentrations of these salts used in the production of NMC materials, the solutions used for NMC precipitation have similarly low NMC:impurity ratios, as indicated in the second table. The main advantage of this invention is that it enables the production of NMC materials from materials containing higher levels of impurities without the costly step of removing these impurities from solution prior to NMC production, thus avoiding the cost of purifying the feed to such low impurity concentrations. [A] [B] [nickel,] [quality%] >22.3 >22.2 [Cobalt, ppm] <10 <10 [Manganese, ppm] <2 <10 [iron] [,ppm] <3 <10 [Copper, ppm] <1 <5 [Sodium, ppm] <15 <20 [Calcium, ppm] <4 <5 [Magnesium, ppm] <10 <10 [Zinc, ppm] <3 <5 [Lead, ppm] <5 <5 [chromium] [,ppm] <5 <5 [cadmium] [,ppm] <1 <5 [Aluminum, ppm] <5 <5 [Silicone, ppm] <10 <20 [Potassium, ppm] <10 <20 [Chloride, ppm] <10 <5 [Fluoride, ppm] <1 <1 [arsenic] [,ppm] <1 <5 [mass ratio] [Ni:] [Impurities] [A] [mass ratio] [Ni:] [Impurities] [B] [Mollbi] [Ni:] [Impurities] [A] [Mollbi] [Ni:] [Impurities] [B] [cobalt] <22300 <22300 <22391 <22391 [manganese] <111500 <22300 <104367 <20873 [iron] <74333 <22300 <70726 <21218 [copper] <223000 <44600 <241439 <48288 [sodium] <14867 <11150 <5823 <4367 [calcium] <55750 <44600 <38068 <30455 [magnesium] <22300 <22300 <9235 <9235 [Zinc] <74333 <44600 <82802 <49681 [lead] <44600 <44600 <157448 <157448 [chromium] <44600 <44600 <39511 <39511 [cadmium] <223000 <44600 <427109 <85422 [aluminum] <44600 <44600 <20503 <20503 [Silicone] <22300 <11150 <10671 <5336 Potassium <22300 <11150 <14855 <7428 [chloride] <22300 <44600 <13470 <26940 [Fluorides] <223000 <223000 <72182 <72182 [arsenic] <223000 <44600 <284661 <56932

[0167] In some prior art documents, the feed for preparing the NMC coprecipitation solution is an NMC-type material or a material previously used or potentially used as a cathode in a battery pack, which may contain some impurity elements and at least one of Ni, Co, and Mn. In such cases, the feed may contain very few (if any) impurities, or the concentration of impurities in the feed may be so low that the material is equivalent to a standard highly purified feed. In such cases, coprecipitation can be carried out under non-selective conditions.

[0168] The feed used in these methods (or the feed mixture in step A) may include recycled materials containing impurities, mineral products, intermediate products and / or NMC salts.

[0169] Recyclable materials may include, but are not limited to, spent lithium-ion battery packs (black lumps) and catalysts containing nickel, cobalt, and / or manganese. Recyclable materials may contain at least one of Co, Mn, and Ni, and at least one impurity. Many prior art methods fail to account for the presence of impurities such as the following black lumps: Zn, Cr, W, P, Ti, S, Pb, K, Mo, Nb, Ba, Cd, V, Rb, Y, Zr, Pt, Sb, Sc, Si, and / or Sn. Such impurities can be substantially or completely removed from the coprecipitates formed by the methods of this application. In some cases, some impurity elements are present in some recycled materials through contamination or through changes in the composition of the initial lithium-ion battery pack.

[0170] Minerals and / or mineral intermediates containing one or more of nickel, cobalt, and manganese can be leached to prepare an aqueous feed solution suitable for coprecipitation. Such feeds may inherently contain impurities and may include laterite and sulfides (and their flotation concentrates) as well as further processed feeds such as MHP and MSP. To the inventors' knowledge, the production of coprecipitates from such feeds containing numerous types of impurities at concentrations present in such minerals and mineral intermediates has not been considered in the prior art.

[0171] NMC salts containing impurities can be, for example, combinations of pure Co and Mn salts with Ni salts containing at least one impurity, or other combinations of pure salts and impure salts.

[0172] In one embodiment, step (ii) may include the following steps: coprecipitating at a lower pH, changing the alkali dosing method, changing the type of alkali, adding a precipitant, or adjusting the concentration of at least two metals in the aqueous feed solution. Such steps can help control the selectivity of the coprecipitation. For example, carbonate alkalis (such as sodium carbonate) may be less suitable for aqueous feed solutions containing high concentrations of Ca due to the formation of stable CaCO3. In this case, hydroxide alkalis can improve selectivity. The alkali dosing method may include continuous, semi-continuous, semi-batch, or batch dosing, or a combination thereof. The method of the present invention can also help control the physical properties of the coprecipitate. Such physical properties may include particle size, bulk density, knock-tightness, morphology, shape, and crystallinity.

[0173] In one embodiment, the co-precipitation step (step (ii)) may include adding a precipitant to the feed solution. The precipitant may be an oxidizing agent, a base, or an organic anionic compound. Oxidizing and reducing agents may be as defined elsewhere in this specification. The organic anionic compound may comprise oxalate. The precipitant may be added stoichiometrically to at least two metals (e.g., at least 1 equivalent, 1.5 equivalent, 2 equivalent, 2.5 equivalent, or 3 equivalent of precipitant). The precipitant may be added substoichiometrically to at least two metals (e.g., less than 1, 0.9, 0.8, 0.7, or 0.6 equivalent of precipitant). Using substoichiometric precipitants may result in the recovery of less than 100% of at least two metals from the feed solution.

[0174] Following the co-precipitation step (step (ii)), the method may additionally include mixing with lithium. This may include calcination. These steps can induce the formation of a cathode active material (CAM).

[0175] Oxidation can also be controlled by adding an oxidant to the feed solution (which may include controlling or adding an oxidant in gaseous form) to cause oxidation of one or more of Mn, Co and Ni prior to step (ii) in order to adjust or achieve a certain proportion of these elements in the solid and allow for greater selectivity of these elements than impurity elements during the coprecipitation step.

[0176] Once a coprecipitate has formed, it can be separated by any suitable means. These include sedimentation, centrifugation, filtration, decantation, and any combination thereof. The method may include decantation and / or filtration to separate the coprecipitate. The separated coprecipitate can then be washed. It can be washed with a suitable detergent to remove any unwanted impurities. Suitable detergents are alkaline, water, acid, or ammonia detergents. Alkaline detergents may have a pH greater than about 9 or greater than about 10, 11, or 12.

[0177] The coprecipitate and lithium may be added after washing, if necessary. Therefore, the method may include adding lithium to the coprecipitate. The lithium may be in the form of, for example, lithium hydroxide or lithium carbonate. This may be done by physically mixing the coprecipitate with the lithium. The lithium may be added in a molar ratio greater than approximately 1:1 of the sum of Ni, Co, and Mn.

[0178] The coprecipitate can be dried. It can be dried at any suitable temperature, such as about 80°C and about 150°C, or between about 80°C and 100°C, 100°C and 150°C, 100°C and 130°C, 130°C and 150°C, or 90°C and 120°C, such as about 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C. It can be carried out by passing air or some other gas through the coprecipitate at a specified temperature, or it may include allowing the coprecipitate to stand at that temperature. The drying time is sufficient to obtain a moisture content of less than about 10%, or less than about 5%, 2%, 1%, 0.5%, 0.2%, or 0.1% by weight. It can last for at least about 5 hours, or at least about 6, 7, 8, 9 or 10 hours, or about 5 to about 20 hours, or about 5 to 15, 5 to 10, 10 to 15, 15 to 20 or 7 to 12 hours, for example about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 hours.

[0179] In one embodiment, steps (i) and (ii) of the method of the first state can be repeated. That is, the method may include: [(i)] Provide an aqueous feed solution containing at least one metal (or at least two metals) and at least one impurity; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, in order to provide: (a) a coprecipitate containing at least one metal (or at least two metals); and (b) a supernatant containing at least one impurity; [(iii)] Separate the coprecipitate from the supernatant; [(iv)] Dissolve the coprecipitate in solution to provide a solution in which at least one of the metals (or at least two metals) is at least partially dissolved; and [(v)] Adjust the pH of the solution from step (iv) to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, in order to provide: (a) a coprecipitate containing the at least one metal (or at least two metals) and at least two metals; and (b) a supernatant containing the at least one impurity. In one embodiment, step (iv) may include dissolving the coprecipitate in an acidic solution. Step (v) may be characterized as described above with respect to step (ii). This method advantageously allows for easier separation of impurities. For example, the pH of the solution in step (v) may be higher than the pH of the solution in step (ii).

[0180] In one embodiment, the method further includes the step of producing a lithium-ion battery pack using a co-precipitate.

[0181] According to a second aspect of the present invention, a method for producing a precipitate comprising at least one metal selected from nickel, cobalt, and manganese is provided, the method comprising: [(i)] Provide an aqueous feed solution containing at least one metal; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, so as to precipitate the at least one metal from the feed solution.

[0182] Aqueous feed may contain at least one impurity. Therefore, the step of adjusting the pH of the feed solution can provide a supernatant containing the at least one impurity. Therefore, in one embodiment of the second state sample, a method for generating a precipitate is provided, wherein the precipitate contains at least one metal selected from nickel, cobalt, and manganese, the method comprising: [(i)] Provide an aqueous feed solution containing at least one metal and at least one impurity; and [(ii)] Adjust the pH of the feed solution to between about 6.2 and about 11, or as appropriate, between about 6.2 and about 10 or between about 6.2 and about 9.2, in order to provide: (a) a precipitate containing the at least one metal; and (b) a supernatant containing the at least one impurity.

[0183] The characteristics of the second state sample can be described above for the first state sample. Where the context permits, a reference to "at least two metals" in the first state sample can be a reference to "at least one metal" in the second state sample. Similarly, where the context permits, a reference to "coprecipitate" in the first state sample can be a reference to "precipitate" in the second state sample.

[0184] In the third state sample, a coprecipitate (or precipitate) comprising at least two metals selected from nickel, cobalt and manganese is provided, which is produced by the method of the first or second state sample.

[0185] This invention relates to the formation of coprecipitates containing nickel, manganese, and / or cobalt, applicable to the production of precursor materials for lithium-ion battery packs. A mixture of Ni, Co, and / or Mn-containing materials containing some impurities can be at least partially selectively dissolved, for example, using the process described in this application. If necessary, the resulting solution can be treated to remove some impurities and can be mixed with sufficient amounts of one or more other Ni and / or Co and / or Mn-containing solutions to achieve the desired Ni:Mn:Co ratio. A coprecipitate can then be selectively formed in the solution in the presence of any residual impurities, such that the filtered, washed, and cleaned product is appropriately pure and possesses suitable properties relative to the impurities, enabling sufficient performance as a battery pack material after further processing.

[0186] In one embodiment, the coprecipitate has or contains less than about 1000 ppm iron, or less than 500 ppm iron, or less than 200 ppm iron, or less than 100 ppm iron, or less than 50 ppm iron, or less than about 40 ppm iron, or less than about 20 ppm iron, or less than about 10 ppm iron, or less than about 5 ppm iron, or less than about 2.5 ppm iron, or less than about 1 ppm iron. In another embodiment, the coprecipitate contains less than 50,000 ppm or less than 20,000 ppm, less than 10,000 ppm, less than 5,000 ppm, less than 2,000 ppm, less than 1,000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm magnesium. In another embodiment, the coprecipitate contains less than 50,000 ppm or less than 20,000 ppm, less than 10,000 ppm, less than 5,000 ppm, less than 2,000 ppm, less than 1,000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm of calcium. In another embodiment, the coprecipitate contains less than 50,000 ppm or less than 20,000 ppm, less than 10,000 ppm, less than 5,000 ppm, less than 2,000 ppm, less than 1,000 ppm, less than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm of alkaline earth metals. In another embodiment, the coprecipitate contains less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm of alkali metals. In another embodiment, the coprecipitate contains metals other than alkali metals and alkaline earth metals, in amounts of less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm. In another embodiment, the coprecipitate contains less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm of metalloids.In another embodiment, the coprecipitate comprises anionic species, other than hydroxides or carbonates, at concentrations of less than 10,000 ppm, less than 5,000 ppm, less than 3,000 ppm, less than 2,000 ppm, less than 1,500 ppm, less than 1,000 ppm, less than 500 ppm, less than 200 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, less than 10 ppm, or less than 5 ppm.

[0187] In the fourth state sample, the present invention provides the use of the coprecipitate of the third state sample for the production of lithium-ion battery packs.

[0188] The features of the third and fourth versions of the present invention can be described as described with respect to the first version of the present invention.

[0189] According to a fifth embodiment of the present invention, a method is provided for generating a leachate containing at least two metals selected from nickel, cobalt, and manganese, the method comprising: [A.] A feed mixture comprising at least two of the metals is provided, wherein the feed mixture is one of an oxidizing feed, a reducing feed, or an unoxidized feed, wherein: The oxidizing feed comprises at least two metals having an oxidation state greater than 2 than an oxidation state less than 2; The reduction feed comprises at least two metals having an oxidation state less than 2 and more metals having an oxidation state greater than 2, or comprises at least two metals substantially all having an oxidation state of 2 and at least some of the at least two metals in sulfide form; and The unoxidized feed contains at least two metals that are substantially all in an oxidation state of 2, and substantially none of the at least two metals in their sulfide form; [B.] The feed mixture is treated with an aqueous solution to form a leachate containing at least two of the metals, wherein the pH of the aqueous solution is such that the pH of the leachate is between about -1 and about 7 (or between about -1 and about 6; or between about 1 and about 7; or between about 1 and about 6), and wherein: If the feed mixture is an oxidizing feed, the treatment further includes adding a reagent containing a reducing agent; and If the feed mixture is a reducing feed, the process further includes adding a reagent containing an oxidizing agent; The leachate contains at least two metals with an oxidation state of 2.

[0190] The features of the fifth state of the present invention may be as described with respect to the first or second state of the present invention.

[0191] According to a sixth embodiment of the present invention, a method is provided for producing a leachate containing at least two metals selected from nickel, cobalt, and manganese, the method comprising contacting a mixture containing at least two metals with an aqueous solution at a certain pH such that the pH of the leachate is between about 1 and about 7 (or between about 1 and about 6), thereby providing the leachate containing the at least two metals in solution; wherein at least a portion of the at least two metals in the feed mixture has an oxidation state of 2.

[0192] The method for the sixth state sample may include a step of treating the mixture with a reducing agent. In one embodiment, at least a portion of the nickel, cobalt, and / or manganese may be in an oxidized state, and the treatment may reduce at least a portion of the oxidized nickel, cobalt, and / or manganese. It should be noted that this embodiment is similar to the fifth state sample of the present invention. In one embodiment, the method for the sixth state sample may include a step of removing one or more impurities from the leachate.

[0193] The features of the sixth state of the present invention can be described as described with respect to the fifth state of the present invention.

[0194] In the seventh state sample, the present invention provides a leaching solution containing at least two metals, or in some cases all three metals, wherein the metals are selected from nickel, cobalt and manganese, and the leaching solution is produced by the method of the fifth state sample.

[0195] In the eighth state sample, the present invention provides a leaching solution containing at least two metals, or in some cases all three metals, wherein the metals are selected from nickel, cobalt and manganese, and the leaching solution is produced by the method of the sixth state sample.

[0196] Any of the features described herein may be combined with any or more of the other features described herein that are within the scope of this invention in any combination.

[0197] In one embodiment, the invention relates to the dissolution of a specific metal, specifically, the dissolution of two or three of nickel, cobalt, and manganese. Dissolution can be carried out in at least a partially selective manner. This is done to maintain Ni+Mn, Ni+Co, or Mn+Co, or practically Ni+Mn+Co, with minimal dissolution of impurities and / or minimal loss of Ni, Co, or Mn, by controlling the final pH between about 1 and about 7 or between about 1 and about 6, and by controlling the oxidation and reduction reactions, and to produce a solution having a substantially appropriate proportion for precipitating battery pack precursor materials. This process can subsequently remove and / or separate some impurities from the resulting solution, making the resulting solution usable for producing battery pack precursor materials. Depending on the initial solid material, this may require the use of a reducing agent, an oxidizing agent, or neither. The material need not necessarily include all Ni, Mn, and Co, nor need it include all Ni, Mn, and Co for the final product. This process is intended to produce a solution for producing precursor materials.

[0198] One aspect of this method involves keeping most of the selected metals together through leaching and impurity removal or separation steps, allowing the Ni:Mn:Co ratio in the resulting leachate to be adjusted and used in the precipitation of NMC-type materials.

[0199] In one embodiment, the feed mixture used in the method of the present invention may include residues from the SAL process, products from the process, battery pack materials, other oxide materials (such as nickel oxide ore), intermediate nickel products such as MHP (mixed hydroxide precipitates), mixed carbonate precipitates (MCP) or mixed sulfide precipitates (MSP), other sulfide materials (such as nickel sulfide ore, nickel sulfide concentrate or nickel sulfide matte) or metallic materials, provided that such materials contain at least a significant amount of at least two of Ni, Co and Mn.

[0200] These materials can generally be classified by the oxidation states of Ni, Co, and Mn. Nickel and cobalt typically exist in metallic forms that can be referred to as Ni(0) or Co(0). These can be oxidized to ionic forms Ni(II) or Ni(III) and Co(II) or Co(III). Mn can exist in the forms Mn(0), Mn(II), Mn(III), Mn(IV), and Mn(VII). Other oxidation states of these elements can exist but are less common. In order to dissolve these metals in a relatively selective manner, the inventors have found that it is convenient to change the oxidation state of the elements to the (II) state. Therefore, it is considered to oxidize any material of Ni, Co, and Mn in a state higher than (II) compared to the desired (II) form, and to reduce any material in an oxidation state lower than (II) compared to the desired (II) form. The reason for obtaining these elements in state (II) is that, in this form, all three of these metals are significantly soluble in acidic solutions of sulfuric acid, nitric acid, or hydrochloric acid at pH between approximately 1 and at most approximately 6 or 7. In contrast, in the case of Mn, (III) or (IV) are significantly soluble only in such acidic solutions at pH below approximately 3. Therefore, obtaining elements in state (II) allows them to dissolve under less acidic conditions. This provides selectivity for a variety of impurities.

[0201] The residue from the SAL process contains mostly Ni(II) Ni, mostly Co(III) or a mixed Co(II) / Co(III) solid, and mostly Mn(III) or Mn(IV). This can be classified as an oxidized feed. The cathode material for battery packs contains mostly Ni(III) Ni, mostly Co(III) Co, and mostly Mn(III) and Mn(IV). This can be classified as an oxidized feed. Nickel oxide ore may contain Ni(II) or Ni(III), Co(II) or Co(III), and Mn(II), Mn(III), and Mn(IV). This can be classified as an oxidized feed. MHP and MCP intermediates contain mostly Ni(II) Ni, mostly Co(II) Co, and mostly Mn(II). This feed will be classified as an unoxidized feed.

[0202] Most of the Ni in MSP and other sulfide materials is Ni(II), and the Co is Co(II). A very small amount of Mn is usually present, associated with the sulfides. In these sulfide materials, the Ni and Co are bound to sulfur; therefore, to dissolve them, it is not necessary to oxidize or reduce Ni or Co, but it is necessary to oxidize sulfur to allow Ni and Co to be released from their sulfide forms. Therefore, sulfide sources will be classified as reducing feedstocks.

[0203] The metallic form will have most Ni as Ni(0), most Co as Co(0), and most Mn as Mn(0), but may contain small amounts of these elements in oxide form, which are also in the (II) state, which is also associated with the metal. Therefore, these will be classified as reduction feedstock.

[0204] Generally, oxidized feeds will require reduction with a suitable reducing agent to dissolve them and form a leachate. Unoxidized feeds will not require a significant reducing or oxidizing agent to dissolve Ni, Co, and / or Mn in order to form a leachate. Reduced feeds will require oxidation with a suitable oxidizing agent to allow them to dissolve in order to form a leachate.

[0205] In one embodiment, the method of the present invention is characterized in that, in the oxidizing feed, nickel oxide is typically the first element to be reduced, followed by cobalt oxide, and then manganese oxide. These three elements can be reduced to the desired +2 oxidation state, and thus dissolved in a manner that controls the amount of each element in the leachate. The degree of dissolution of these metals can also be controlled by the selection of the reducing agent or even the subsequent use of an oxidizing agent.

[0206] Furthermore, this behavior allows for the reduction and dissolution of large quantities of Ni / Co / Mn metals before the reducing agent reacts with a large amount of consuming reducing agent and / or other elements dissolved by the reduction reaction. Fe is an example of an element that follows similar properties to Ni and Co. That is, Fe can exist in both Fe(II) and Fe(III) states, with Fe(II) being significantly soluble in acids below about pH 7 and Fe(III) being significantly soluble only below about pH 3. However, reduction can be controlled by carefully managing the rate of reagent addition, the amount added, the choice of reagent, the temperature, and other parameters to stop or minimize the reduction of Fe(III) to Fe(II) until most of Ni, Co, and Mn have reacted to their (II) forms. Alternatively, an oxidant can be added after reduction. This oxidant will react with Fe(II) rather than Ni(II)Co(II) or Mn(II), or react with at least Fe(II) before reacting with Ni(II)Co(II) and / or Mn(II), causing Fe(II) to oxidize back to Fe(III) and return to the solid phase. Thus, selective dissolution of Ni / Co / Mn away from Fe can be achieved in Ni / Co / Mn-containing materials. Following the selective dissolution step can be a solid / liquid separation step, such as decantation, centrifugation, sedimentation, and / or filtration.

[0207] This method of controlling reduction and oxidation can also be applied to reduced raw materials, such as sulfides and metal sources of Ni, Co, and Mn. Sulfide materials can react with an oxidizing agent to partially oxidize the sulfide and dissolve Ni, Co, and Mn. The oxidizing agent and solubility can be controlled so that the Ni, Co, and Mn portions of the material are significantly oxidized and dissolved before other impurities in the material are oxidized and / or dissolved, thereby producing a relatively clean solution containing Ni, Co, and Mn. The material or solution can also be further oxidized to oxidize and precipitate any impurity elements, such as Fe, before the large amounts of Mn, Co, or Ni are oxidized and precipitated.

[0208] Similarly, metals can react with oxidizing agents (such as those described above) to partially oxidize the Ni / Co / Mn content to its (II) state and dissolve it, thereby controlling the degree of oxidation to prevent the dissolution of any other metallic material oxidized after Ni, Co, and / or Mn metals (such as noble metals and platinum group metals) or even more precious metals (including copper, lead, and tin). Other oxidation methods can also be used to oxidize and precipitate impurity metals such as Fe, or even oxidize and precipitate Mn to allow control of the Ni:Co:Mn ratio in solution.

[0209] The main leaching impurities typically associated with these materials are alkali metals (primarily Li, Na, K), alkaline earth metals (primarily Mg, Ca), transition metals (primarily Sc, Ti, V, Cr, Fe, Cu, Zn, Cd), other metals (primarily Al, Sn, Pb), and metalloids (primarily Si, As, Sb).

[0210] Metals such as Li(I), Na(I), and K(I) are highly soluble in acidic solutions and do not exhibit stable or oxidative precipitation behavior, and will therefore typically dissolve under the leaching conditions used in the processes described herein. Mg(II) exhibits similar behavior. Ca(II) is generally also soluble; however, in sulfuric acid, its concentration will be limited to relatively low levels due to the solubility of various calcium sulfate compounds. Generally, these elements are not a primary concern because they are soluble in solutions with a pH of at most above approximately 8 or 9, and therefore will not contaminate battery precursor products, as they will remain in solution during any subsequent precipitation processes used to recover Ni, Co, and / or Mn.

[0211] For other significant impurity elements, Fe dissolution can be controlled by the oxidation-reduction and pH characteristics discussed above. The dissolution of Sc(III), Ti(IV), V(V), Cr(III), Al(III), Sn(IV), As(III), Sb(III), and to a certain extent Cu(II), Zn(II), and Cd(II) can be controlled by leaching pH, as these elements are significantly soluble at lower pH values ​​and not significantly soluble at higher pH values ​​in the range of approximately 1-7 or 1-6. Pb(II) is generally also soluble; however, its solubility in sulfuric acid is limited by the solubility of various lead sulfate compounds. Si is generally not significantly soluble in the pH range of approximately 1-7 or 1-6.

[0212] Cr, Sn, As, and Sb can all be in other oxidation states that affect their solubility. Generally, the higher oxidation states of these elements are more soluble, so their oxidation or reduction can be controlled to achieve the mentioned oxidation states, which in turn will achieve the desired selectivity of Ni / Co / Mn relative to these elements.

[0213] As discussed above, the objective of the method described in one embodiment of this article is to obtain Ni, Co and / or Mn and minimal impurities in the solution by controlling the oxidation and reduction reactions and the solution pH.

[0214] Subsequent impurity removal steps, such as pH adjustment, ion exchange, solvent extraction, precipitation, and / or cementation reactions, can be performed to remove and / or separate other impurities from the solution. For example, Cu, Zn, and Cd can be removed from the solution by various ion exchange or solvent extraction processes. Alternatively or additionally, any two or all of Ni, Co, and Mn can be separated from impurities in the leachate by ion exchange or solvent extraction, thus retaining these impurities along with the leachate.

[0215] The proportions of different materials used in the leaching process can be adjusted to target the desired Ni:Co:Mn ratio in the final leachate.

[0216] Additional Ni, Co, or Mn may be added to the leachate before or after any impurity removal step to adjust the Ni:Co:Mn ratio as needed.

[0217] In one embodiment, the ultimate goal may be a solution with the desired Ni:Co:Mn ratio and sufficient purity, such that the cathode precursor material for the battery pack can be produced from the solution.

[0218] It should be noted that the term NMC refers to any material containing Ni, Co and Mn, which can be used as an active material in battery packs. Simple Explanation of the Diagram

[0219] Preferred features, embodiments, and variations of the present invention can be identified from the following embodiments, which provide sufficient information for those skilled in the art to implement the present invention. These embodiments should not be construed as limiting the scope of the foregoing description of the present invention in any way.

[0220] Regardless of any other form that may fall within the scope of this invention, preferred embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0221] Figure 1 shows a flowchart of a method for producing a coprecipitate of nickel, manganese, and cobalt obtained from a solid residue according to a method including one embodiment of the present invention;

[0222] Figure 2 illustrates a schematic diagram of a second method for producing a coprecipitate comprising nickel, manganese, and cobalt according to a method including a second embodiment of the present invention;

[0223] Figure 3 illustrates the removal of unwanted metals from cobalt concentrate using an acid pre-washing step based on filtrate volume; and

[0224] Figures 4a and 4b show the recovery rates of various metals to the solution as a function of pH during the leaching of pre-washed cobalt concentrate under reducing conditions;

[0225] Figures 5a, 5b, and 5c show the curves illustrating the changes in the solution phase concentrations of various metals during the termination of the reduction reaction;

[0226] Figures 6a-6d show the recovery rates of major elements to solution relative to reaction time and pH. The solids were treated at a reactor temperature of 55°C with 5% initial solids and 100% stoichiometric SO₂ for 2.5 hours. The solids used are: Figure 6a - BMJ-A; Figure 6b - BMJ-B; Figure 6c - BMC; Figure 6d - BMK.

[0227] Figures 7a-7d show the recovery rates of major elements to the solution relative to reaction time and pH. The BMK solid was treated with 5% initial solid and 100% stoichiometric SO2 at a reactor temperature of 55°C, and acid was added under various conditions. The following acid additions were made: Figure 7a - H₂SO₄ was added gradually at the sampling point to lower the pH to 4.5, and SO₂ was added over 2.5 hours (31 mL / min); Figure 7b - H₂SO₄ was added continuously to obtain 100% stoichiometric amount (1 mL / min) over 200 minutes, and SO₂ was added over 2.5 hours (31 mL / min); Figure 7c - H₂SO₄ was added continuously to obtain 100% stoichiometric amount (2.2 mL / min) over 1.5 hours, and SO₂ was added over 1.5 hours (52 mL / min); Figure 7d - 100% stoichiometric amount of H₂SO₄ was delivered at the start of the reaction, and SO₂ was added over 0.5 hours (220 mL / min). Figure 7e shows a comparison of the recovery rates of major elements to the solution relative to reaction time and pH. The BMK solid was treated with 5% initial solids at a reactor temperature of 55°C without SO2, and H2SO4 was continuously added to obtain 100% stoichiometric amount (1 mL / min) within 200 minutes.

[0228] Figure 8 shows the recovery rates of major elements to the solution as a function of reaction time and pH. The BMK solid was treated with 20% of the initial solid at a reactor temperature of 55°C for 1.5 hours with 100% stoichiometric addition of SO₂ (290 mL / min) and continuously supplemented with 50% H₂SO₄ to achieve 100% stoichiometric addition (2.9 mL / min) within 1.5 hours.

[0229] Figures 9a and 9b show the recovery rates of major elements to the solution relative to reaction time and pH. In the figure, BMK solid was treated with 5% initial solid and 100% stoichiometric addition (52 mL / min) of SO₂ over 1.5 hours at the reactor temperature, with continuous addition of H₂SO₄ to achieve 100% stoichiometric addition (2.2 mL / min) within 1.5 hours. Reactor temperatures were: Figure 9a - 75℃; Figure 9b - 35℃.

[0230] Figure 10 shows a flowchart of a method according to an embodiment of the present invention;

[0231] Figure 11 shows a flowchart of a method according to another embodiment of the present invention;

[0232] Figure 12 shows the pH versus target metal precipitation at 75°C, 50 ml / min air, and pH adjusted by automatic titration with 2.5 M NaOH.

[0233] Figure 13 shows the precipitation of impurity elements relative to pH at 75°C, 50 ml / min air, and pH adjusted by automatic titration with 2.5 M NaOH.

[0234] Figure 14 shows the pH versus target metal precipitation at 75°C, 50 ml / min air, and pH adjusted by automatic titration with 200 g / L Na₂CO₃.

[0235] Figure 15 shows the precipitation of impurity elements relative to pH at 75°C, 50 ml / min air, and pH adjusted by automatic titration with 200 g / L Na₂CO₃.

[0236] Figure 16 shows the pH versus target metal precipitation at 75°C, 50 ml / min air, and pH adjusted by adding solid MnCO3 and BNC followed by automatic titration with 200 g / L Na2CO3 for initial pH adjustment;

[0237] Figure 17 shows the pH versus precipitation of impurity elements at 75°C, 50 ml / min air, and pH adjusted by adding solid MnCO3 and BNC followed by automatic titration with 200 g / L Na2CO3.

[0238] Figure 18 shows the pH versus target metal precipitation at 75°C, 50 ml / min air, and pH adjusted by automatic titration with 200 g / L Na₂CO₃. Solid-liquid separation was performed by adding alkali at 150 minutes, continuing until 180 minutes.

[0239] Figure 19 shows the precipitation of impurity elements relative to pH at 75°C, 50 ml / min air, and pH adjusted by automatic titration with 200 g / L Na₂CO₃. Solid-liquid separation was performed by adding alkali at 150 minutes, continuing until 180 minutes.

[0240] Figure 20 shows the effect of the final pH and initial NMC ratio on the final NMC composition;

[0241] Figure 21 shows the precipitation degree of Ca²⁺ and Mg²⁺ at different final precipitation pH values ​​of NMC. The initial solution contained 50 mg / L Ca + 200 mg / L Mg. Initial concentrations of 0.12 mol / L Ni, 0.02 mol / L Co, and x mol / L Mn (x = 0.02, 0.04, and 0.06) varied the NMC ratio from 6:2:2 to 6:3:2 and 6:4:2.

[0242] Figure 22 shows the precipitation percentages of Ni²⁺, Co²⁺, and Mn²⁺ at different final precipitation pH values ​​of NMC. Initially, 0.12 mol / L Ni, 0.02 mol / L Co, and x mol / L Mn (x = 0.02, 0.04, and 0.06) in the solution caused the NMC ratio to change from 6:2:2 (solid red dots) to 6:3:2 (red circles) and 6:4:2 (red rectangles).

[0243] Figure 23 illustrates the leaching and recovery from a laterite sample according to one embodiment of the present invention;

[0244] Figure 24 illustrates the recovery rate of NMC precipitate to solids from a conditioned laterite ore leaching solution according to one embodiment of the present invention;

[0245] Figure 25 illustrates the leaching recovery rate of the solution from the sulfuric acid leaching of MSP according to one embodiment of the present invention;

[0246] Figure 26 illustrates the recovery rate of NMC precipitate to solids from a regulated sulfide concentrate leaching solution according to one embodiment of the present invention; and

[0247] Figure 27 illustrates the leaching recovery rate from sulfuric acid leaching of blended cobalt concentrate / black lumps according to one embodiment of the present invention to the solution. Implementation

[0248] Cross-reference

[0249] This application claims priority to Australian Provisional Patent Application No. 2021900570, filed on 2 March 2021, and Australian Provisional Patent Application No. 2021900571, filed on 2 March 2021; the contents of these applications are incorporated herein by reference in their entirety.

[0250] The exemplary method of the present invention will now be discussed with reference to Figures 1 to 27.

[0251] Figure 1 illustrates a first exemplary method 10 for producing the coprecipitate comprising nickel, manganese, and cobalt of the present invention. The precipitation method mainly relates to the first 25 steps.

[0252] The method includes the step of treating a mixture 15 containing nickel, cobalt, and manganese in an aqueous solution with a reducing agent at a pH of about 1 to 6 (at 20). In the mixture 15, a portion of the nickel, cobalt, and / or manganese is in an oxidized state, and the treatment with the reducing agent reduces at least a portion of the oxidized nickel, cobalt, and / or manganese, thereby providing an aqueous solution containing dissolved nickel, cobalt, and manganese.

[0253] The mixture is particularly a wet filter cake, especially obtained from the selective acid leaching (SAL) process disclosed in PCT / AU2012 / 000058 (but cathode materials including nickel, cobalt, and manganese from lithium-ion battery packs can also be used). Broadly, the wet filter cake is obtained by contacting a mixed hydroxide precipitate containing nickel, cobalt, and manganese with an acidic solution containing an oxidant at a specific pH to stabilize cobalt in the solid phase while dissolving nickel in the acidic solution; and subsequently separating the solid phase from the acidic solution, wherein the solid phase contains at least nickel, cobalt, and manganese. In this exemplary embodiment, the solid phase is a wet filter cake.

[0254] In the treatment steps using leaching and reducing agents, the wet filter cake may include cobalt, nickel, and / or manganese in oxidized forms, namely Co(III), Co(IV), Mn(III), Mn(IV), Mn(VII), Ni(III), or Ni(IV). However, the material may also contain significant amounts of unoxidized or unreduced cobalt, manganese, or nickel, for example, in the form of Co(II), Mn(II), or Ni(II). Reduced cobalt, manganese, and nickel are more soluble in aqueous solutions with a pH of 1 to 6 than their oxidized forms.

[0255] During the treatment steps, the pH may decrease over time. A preferred final pH for the treatment steps is approximately 3-4 (although a final pH of approximately 2-3 may be suitable under more corrosive conditions), and the pH is maintained at this level by adding other leaching agents or alkalis during the treatment steps. Sulfuric acid is preferred as the leaching agent; however, hydrochloric acid, nitric acid, or organic acids may be suitable. Sulfur dioxide gas is preferred as the reducing agent in the treatment steps because it is sufficient to reduce cobalt, manganese, and nickel without introducing any additional impurities into the aqueous solution. The addition of the reducing agent is controlled during the treatment steps to control the reduction of cobalt, nickel, and / or manganese. The treatment steps are carried out in a sealed container to control gas loss. The reducing agent is added in a controlled manner using approximately 1 stoichiometric amount of reducing agent for a combined molar amount of cobalt oxide, manganese oxide, and nickel oxide in the mixture. The treatment steps are carried out with stirring at a temperature of approximately 80°C to approximately 95°C for approximately 2 hours, or with stirring at a temperature of approximately 55°C for approximately 1-5 hours.

[0256] Following step 20, the aqueous feed solution of the present invention comprises dissolved nickel, cobalt, and manganese, as well as impurities such as arsenic, aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, ammonium, sulfites, fluorine, fluorides, chlorides, titanium, zinc, scandium, and zirconium; particularly aluminum, copper, and iron (e.g., if originating from materials derived from black lumps) or zinc, calcium, and magnesium (and iron and aluminum) (e.g., if originating from materials derived from MHP). The aqueous solution also contains entrained solids, which include impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium.

[0257] After processing step 20, one or more impurities are removed from the aqueous solution containing dissolved nickel, cobalt, and manganese. The solids are removed from the liquid by flowing the liquid from processing step 20 with entrained solids to a settling tank for decanting / filtration 25. The solids removed from the settling tank are returned to processing step 20. The liquid removed from the settling tank is further processed at 35 to remove impurities. Exemplary impurities removed from the liquid may include iron, copper, zinc, and aluminum, and this can be achieved using precipitation and / or ion exchange separation techniques. Ion exchange can help remove, for example, at least some zinc.

[0258] After removal and / or separation of impurities, nickel, cobalt, and manganese are co-precipitated from the aqueous solution at 40°C. However, prior to coprecipitation, additional cobalt, nickel, and / or manganese may be added to adjust the nickel, cobalt, and manganese ratio to the desired proportion, or to provide the desired proportion in the coprecipitate. An illustrative ratio is 1:1:1 nickel:cobalt:manganese. The added cobalt, manganese, and nickel may be in the form of CoSO₄, NiSO₄, and / or MnSO₄, or other compounds containing cobalt, manganese, and nickel.

[0259] The coprecipitation step at 40 sites can be performed by adjusting the pH of the solution containing dissolved nickel, cobalt, and manganese, preferably by adjusting the pH of the solution to approximately 7.5 to approximately 8.6. It has been found that this pH range produces less coprecipitate or includes fewer undesirable impurities, such as magnesium and / or calcium salts, compared to using a higher pH range. This step is performed at 80°C and atmospheric pressure. Nickel, cobalt, and manganese coprecipitate as hydroxides. A two-stage resuspension wash can be used, employing a 0.5% NH₃ solution.

[0260] The precipitate is then separated from the liquid, for example, by decantation or filtration at 45°C. Advantageously, other impurities are removed via a co-precipitation step, as some impurities remain in solution, such as sodium, potassium, magnesium, calcium, and sulfates. At 55°C, the liquid is further processed for nickel, manganese, or cobalt recovery (e.g., precipitation or ion exchange), and the solid is washed to remove other impurities, and then mixed with lithium and calcined at 50°C. The calcined product can be used to provide NMC material for use as cathode active material (CAM) in new battery packs.

[0261] A similar method 110 is illustrated in Figure 2. Similar designations refer to similar features. However, the method illustrated in Figure 2 includes, as appropriate, pre-washing. This may be washing with a weakly acidic leaching solution with an initial pH of about 3.5 (the pH will increase as washing progresses), resulting in a solution with about 10% solids. Such pre-washing may be able to remove at least some zinc, magnesium, and calcium.

[0262] Compared to the method illustrated in Figure 1, the method illustrated in Figure 2 also uses a countercurrent setup, as discussed further below. In Figure 2, two mixers 120a and 120b and two settling tanks 125a and 125b are used. As illustrated in Figure 2, a mixture containing nickel, cobalt, and manganese is added to an aqueous solution in the first mixer 120a, and the first mixer is stirred. The solution (including entrained solids) exits the first mixer 120a through the liquid outlet and enters the first settling tank 125a through the liquid inlet. The first settling tank 125a includes at least one upper outlet in the upper part of the container to provide a liquid outlet and a lower outlet in the lower part of the container to provide a settled solids outlet. The liquid exiting the first settling tank through the upper outlet proceeds to the step of separating liquid impurities in the solution at point 135. The liquid / solid mixture exits the first settling tank 125a through the lower outlet and flows into the second mixer 120b through the second mixer inlet. Reducing agent 105 and leaching agent 108 are added to the second mixer 120b, and the second mixer is stirred. The solution (including entrained solids) exits the second mixer 120b through the liquid outlet and enters the second settling tank 125b through the liquid inlet. The second settling tank 125b includes at least one upper outlet in the upper part of the container to provide a liquid outlet and a lower outlet in the lower part of the container to provide a settled solids outlet. The liquid exits the second settling tank through the upper outlet and flows to the inlet of the first mixer 120a. The liquid / solid exiting the second settling tank through the lower outlet is discarded at 130, for example, after passing through a screw press. The advantage of this configuration is that it minimizes the amount of acid and reducing agent remaining in the solution, in which nickel, cobalt, and manganese co-precipitate. Furthermore, it minimizes the iron content in the first mixer by maintaining appropriate conditions.

[0263] As shown in Figure 1, the mixture at 115 is a wet filter cake, particularly obtained from the selective acid leaching (SAL) process disclosed in PCT / AU2012 / 000058 (but cathode materials including nickel, cobalt, and manganese from lithium-ion battery packs can also be used). The SAL process is further discussed above, as well as the oxidation states of cobalt, manganese, and nickel.

[0264] Similarly, the preferred pH for the treatment steps is approximately 3, and the pH is maintained at this pH by adding other leaching agents or alkalis during the treatment steps in mixers 120a and 120b and settling tanks 125a and 125b. Sulfuric acid is preferred as the leaching agent; however, hydrochloric acid or nitric acid may be suitable. Sulfur dioxide gas is preferred as the reducing agent in the treatment steps because it is sufficient to reduce cobalt, manganese, and nickel without introducing any additional impurities into the aqueous solution. The addition of the reducing agent is controlled during the treatment steps to control the reduction of cobalt, nickel, and / or manganese and to optimize the utilization of the reducing agent. The treatment steps are carried out in a sealed container to control gas loss (this gas will require venting and exhaust gas scrubbing). The reducing agent is added in a controlled manner using approximately 1 stoichiometric amount of reducing agent for a combined molar amount of cobalt oxide, manganese oxide, and nickel oxide in the mixture. The treatment steps are carried out with stirring at a temperature of approximately 55°C for approximately 1–5 hours.

[0265] After processing steps 120a and 120b, the aqueous solution contains dissolved nickel, cobalt, and manganese, as well as impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium. The aqueous solution also contains entrained solids, which include impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium.

[0266] The liquid removed from the first settling tank 125a is further processed at 135 to remove impurities. Exemplary impurities removed from the liquid may include iron, copper, zinc and aluminum, and this can be achieved using precipitation and / or ion exchange separation techniques.

[0267] After removal and / or separation of impurities, nickel, cobalt, and manganese are co-precipitated at 140°C from the aqueous solution. However, prior to coprecipitation, additional cobalt, nickel, and / or manganese may be added to adjust the nickel, cobalt, and manganese ratio to the desired proportion, as discussed above with reference to Figure 1. The coprecipitation step at 140°C is as described above with reference to Figure 1.

[0268] The precipitate is then separated from the liquid, for example, by decantation or filtration. At 155°C, the liquid is further processed for nickel, manganese, or cobalt recovery (e.g., precipitation or ion exchange), and the solid is washed to remove other impurities, and then mixed with lithium and calcined at 150°C. The calcined product can be used to provide NMC material for use as cathode active material (CAM) in new battery packs.

[0269] In another embodiment, the method outlined in FIG10 or FIG11 may be used in the method outlined in FIG1 and FIG2 prior to the impurity separation / coprecipitation step. In these methods, nickel oxide, cobalt oxide, manganese oxide material 201 (FIG10) or reduced nickel, reduced cobalt, reduced manganese material 251 (FIG11) is treated with acid 203 / 253 to bring the pH to between about 1 and about 6 or between about 1 and about 7, water 205 / 255 as appropriate, and an oxidizing agent (207) or a reducing agent (257) (depending on the starting material). After leaching the resulting solution in leaching containers 210 / 260, the leachate may be filtered 215 / 265 and impurity solids 218 / 268 are removed. Following this, the leachate is transferred to treatment containers 220 / 270 (note: leachate containers 210 / 260 may be the same as treatment containers 220 / 270), and oxidant 222 (when oxidizing NMC material 201 begins) or reducing agent 272 (when reducing NMC material 251 begins) is added to neutralize any excess reducing agent 207 or oxidant 257 remaining in the leachate. Alkali 224 / 274 may also be added to raise the pH (e.g., the solution in the leachate container may be at a pH of approximately 3, and the solution in the treatment container may be at a pH of approximately 6). Thus, some material may precipitate in treatment containers 220 / 270, which can then be filtered through 230 / 280 to provide impurity solids 232 / 282 and NMC solution 234 / 284.

[0270] Illustrative results of this method are provided below. [, Leaching , ] [, Example , ] [, 1 , ] [, : , ] Derived from the starting materials of MHP Acid prewashing

[0271] In this experiment, cobalt concentrate from the pilot plant (Brisbane Metallurgy Laboratories) was used. Based on total dissolution and solution analysis, the cobalt concentrate had the following elemental composition (%): 61.5 Ni, 18.3 Mn, 15.0 Co, 1.6 Na, 0.9 Zn, 0.9 Mg, 0.7 Fe, 0.4 Cu, 0.4 Al, 0.2 Ca. This cobalt concentrate was prepared using a SAL process, which utilizes a mixed hydroxide precipitate (MHP - a solid mixed nickel-cobalt hydroxide precipitate). The MHP was contacted with an acidic solution containing an oxidant at a specific pH to stabilize cobalt in the solid phase and dissolve nickel in the acidic solution; subsequently, the solid phase, containing nickel, cobalt, and manganese, was separated from the acidic solution.

[0272] The cobalt concentrate is washed with a weak acid to reduce the content of impurities associated with entrained solutions and residual nickel hydroxide. In this example, due to the high solids solution retention during filtration, a combination of reslurry washing and displacement washing using a pressure filter is employed.

[0273] In this method, cobalt concentrate (180 g dry solids) is first mixed with 5 g / L H₂SO₄ at room temperature to produce a slurry with 20% by weight solids. The washed slurry is then placed into a pressure filter; and (i) filtration is stopped after recovering approximately 200 mL of solution; subsequently, (ii) the filter is depressurized and 200 mL of 1 g / L H₂SO₄ is added to the filter, and filtration is resumed. Steps (i) and (ii) are repeated until a total of 1 L of 1 g / L H₂SO₄ has been added to the filter. The remaining solution is filtered out and collected in approximately 200 mL of batch. After recovering the last solution, air is purged onto the filter for 30 minutes.

[0274] As shown in Tables 1 and 2 and Figure 3, this process effectively reduces the Ca (93%) and Mg (93%) content of the solids to be leached, with moderate effectiveness for Ni and Zn (60%). Losses of Co and Mn to the solution are negligible (<10 mg loss per 180 g dry solids feed). No Fe and very little Cu are washed out. The final 500 mL of 1 L acidic wash solution contains very little dissolved metal. [surface] [1] [:] Results of the acid prewashing step - cobalt concentrate starting material and acid prewashed cobalt filter cake [] cobalt concentration Washing filter cake solid% 43% twenty three% Al PPM 1,892 3,134 Ca 697 93 Co 65,426 124,037 Cu 1,777 3,140 Fe 3,060 5,846 Mg 4,071 529 Mn 79,965 150,101 Na 7,124 801 Ni 268,351 233,164 [surface] [2] [:] Percentage of minerals washed out in acid-prewashed cobalt filter cake (relative to minerals in cobalt concentrate) [] Al Ca Co Cu Fe Mg Mn Na Ni Zn Wash out 11% 93% 0% 5% 0% 93% 0% 94% 53% 60% Treatment with reducing agents and acids

[0275] The washed cobalt concentrate was prepared into a 5% wt slurry, heated, and SO2 was bubbled into the reactor to reduce solids at pH 4, which was set as the experimental target. This target was chosen because it showed good recovery in previous tests and had some selectivity for impurity elements. Due to a miscalculation, the initial SO2 flow rate was too low and had to be accelerated to complete the experiment.

[0276] In this process, the washed cobalt concentrate was first slurried in deionized water with 5% solids and heated to 55°C. Then, SO₂ was bubbled into the slurry at a rate of 12 mL / min for 5 hours. The SO₂ flow rate was subsequently increased to 36 mL / min and continued for another 110 minutes until the solution pH reached 4. Finally, the slurry was filtered to recover the solution (filtrate).

[0277] As shown in Table 3 and Figures 4a and 4b, >90% of the target metals (Ni, Mn, and Co) were recovered using reducing agents and acid treatment. Slow addition of SO₂ allowed for the leaching of the target metals, selectively targeting Al, Cu, and Fe until the target values ​​were reached. Ca and Mg leached faster than the target elements; however, due to effective acid washing of the feed solids, the final solution concentration was low (<30 mg / L). [surface] [3] [:] Analysis of treatment with reducing agent under acidic conditions [] Al Ca Co Cu Fe Mg Mn Na Ni S Zn Top Analysis 0.31% 0.01% 12.40% 0.31% 0.58% 0.05% 15.01% 0.08% 23.32% 3.31 % 0.30 % Solution analysis (mg / L) 48 4 5,561 51 65 27 6,958 31 10,254 16,204 137 Recovery rate 31% 83% 92% 33% twenty three% 103% 95% 78% 90% NA 92%

[0278] Without being bound by theory, the inventors believe that the initial acid formation reaction of SO₂ with water is much lower than the reduction reaction of Co³⁺ and Mn⁴⁺ hydroxides, causing the pH to increase. Once most of the reduction is complete, the pH decreases until it is buffered to near pH 5 by the dissolution of divalent hydroxides, and then decreases further as the recovery rate of the solution approaches its maximum. The end of restoration

[0279] The filtrate from the preceding paragraph was contacted with acid-washed cobalt concentrate (as an oxidant) at 80°C to consume any residual SO₂ dissolved in the solution and to precipitate iron. MnCO₃ was added to raise the pH and facilitate the precipitation of impurities, while compensating for the expected Mn loss in ion exchange (IX). However, the pH remained stable (at approximately 4.8) due to the buffering effect attributable to the impurity precipitation reaction.

[0280] In this method, the filtrate is first slurried with 50 g of washed cobalt concentrate (5% solids) and heated to 80°C. After 1 hour, 13.8 g of MnCO3 is added to the slurry, and the slurry is filtered after 8 hours. During this step in the method, the pH is maintained in the range of 5.1–4.6.

[0281] As illustrated in Table 4 and Figures 5a, 5b, and 5c, the addition of MnCO3 at 80°C brought the leaching solution into contact with the unleached solids, resulting in the rapid removal of Al, Cu, and Fe (within minutes of contact with the solids). The concentrations of Ni and Co remained relatively stable, while Mn began to precipitate, subsequently increasing gradually after the addition of MnCO3. [surface] [4] [:] The concentrations of various metals at the beginning and end of the reduction step. Al Ca Co Cu Fe Mg Mn Na Ni Zn Feed (mg / L) 70.5 5.4 5,946 73.3 115 27.7 7,519 32.1 11,010 149.7 Final (mg / L) 4.9 8.3 6,357 1.8 0 54.1 7,992 63.7 9,853 38.9

[0282] In the oxidation tests prior to the addition of MnCO3, the concentrations of Co, Ni, and Zn in the solution all increased, while the final Mn concentration was much lower (similar to the precipitation observed in this experiment where no further dissolution occurred). Despite the addition of MnCO3, the pH remained relatively stable (5.04 immediately after the solid addition, and 4.67–4.87 for the test residue). Ion exchange (IX)

[0283] The filtrate from the preceding paragraph was contacted with Lewatit® VP OC 1026 macroporous ion exchange resin (based on a styrene-divinylbenzene copolymer containing di-2-ethylhexyl phosphate (D2EHPA); the resin is available from Lanxess, Cologne). Contact with the ion exchange resin was carried out in two stages at 40°C. pH control was performed prior to the IX contact using 0.1 MH H₂SO₄ and 1 M NaOH, with a target pH of 3.8–3.9. The resin was washed with 10% H₂SO₄ acid and subsequently adjusted to pH 3.5 before use. Additives listed below are given by resin volume as is, taking into account mass variations during washing. 1. Add 250 mL of filtrate to the bottle and lower the controlled pH to 3.9. 2. Add 120 mL of resin, seal the bottle, and place it in a roller bottle at 40°C for 24 hours. 3. Filter out the resin and add the solution to a clean bottle. 4. Adjust the pH to a maximum of 3.8. 5. Add 120 mL of resin, seal the bottle, and place it in a roller bottle at 40°C for 4 hours. 6. Filter out the resin and recover the solution.

[0284] Based on previous ion exchange (IX) tests, two consecutive contacts were selected at 40°C with minimal pH control to maximize Zn removal and minimize Mn loss. Tables 5 and 6 show the solution analysis results before and after each contact. Dilution correction analysis considers the solution retained in the resin during washing and conditioning. Compared to the previous experiments, both contacts showed excellent Zn removal rates (87% and 91%), while Mn loss was not completely mitigated (15% and 16%). Some Al and Ca were also removed (accumulating 29% and 32%, respectively), with Fe entering IX at <1 mg / L. [surface] [5] [:] Concentration of various metals during ion exchange treatment pH Al Ca Co Cu Mg Mn Na Ni Zn mg / L Before the first IX 3.89 6 11 7,088 2 67 8,937 71 11,450 43 After the first IX (Dilution Correction) 1.67 5 9 7,163 2 68 7,640 72 11,198 6 Before the 2nd IX 3.80 5 8 6,400 2 60 6,803 1,161 9,972 5 After the 2nd IX (Dilution Correction) 1.86 4 7 6,365 2 61 5,712 1,176 9,891 0.4 After the second IX (actual) 1.86 4 6 5,850 2 56 5,250 1,081 9,090 0.4 [surface] [6] [:] Ion exchange results, percentages of various metals on the resin. % on resin Al Ca Co Cu Mg Mn Na Ni S Zn 1st IX 18% 17% 0% 2% 0% 15% 0% 2% 0% 87% 2nd IX 12% 18% 1% 0% 0% 16% 0% 1% 1% 91% build up 29% 32% 1% 0% 0% 28% 0% 3% 1% 99% [, Example , ] [, 2 , ] [, : [,] Derived from starting materials (black lumps) of lithium-ion battery packs Materials and Equipment

[0285] The reagents used in this work were food-grade SO2 and reagent-grade 98% H2SO4. The composition of the black lumpy samples used is provided in Table 7. These samples were obtained from shredded and chemically cleaned lithium-ion battery packs. [, , ] [] [surface] [7] [:] Elemental concentrations of major elements in the black blocky sample [sample] [Moisture] [sample] [source] [Concentration of major elements in wet lumps] [Ni] [Co] [Mn] [Li] [C] [] [weight%] [] [weight%] [BMK () [Dry)] 0 South Korea 35.39% 11.31% 10.68% 6.47% 4.3% [BMJ-A () [Dry)] 0 Japan 34.57% 14.47% 9.72% 6.21% 3% [BMJ-B] 1 Japan 46.95% 9.47% 9.30% 0.00% 0% [BMC] 19 Canada 20.43% 10.65% 2.41% 3.49% 28%

[0286] All reactions were carried out in a 1.1 L glass reactor with baffles. Temperature was maintained by a hot plate with thermocouple feedback control. Agitation was achieved by a top-mounted stirrer set to 800 RPM with a high-shear Teflon impeller. The gas addition rate was controlled by bubbling the gas using a glass bubbler connected to a gas flow meter. Care was taken to ensure the bubbler was submerged at a constant level consistent with the impeller blades to ensure maximum gas dispersion during the reaction. method

[0287] First, weigh the required amount of the black lumps directly into the reactor. Then add the required amount of water and heat the reactor to the reaction temperature. Once at the reaction temperature, obtain the initial sample by pipetting and cool it to room temperature in a sealed syringe. After cooling, filter the sample using a syringe and dilute it in nitric acid, returning any excess sample to the reactor. When appropriate, bubble SO2 and insert a hose from the acid pump into the reactor and start timing. Following the sample method outlined as for the initial sample, obtain samples at predetermined experimental time intervals.

[0288] Once the reaction time has elapsed, the reactor is weighed for mass balance purposes, and the slurry is vacuum filtered. The wet solids are then dried overnight at 105°C, and the solution is stored in glass bottles.

[0289] The addition rates of SO₂ and H₂SO₄ are calculated based on the flow rate required to react all Li, Ni, Mn, and Co to their divalent states within the desired time when 100% stoichiometric dosage is applied. This assumes that all Ni and Co exist in their trivalent state and Mn exists in its tetravalent state. Results - Influence of Sample Type

[0290] Four different black block samples were processed at 55°C using only SO₂ gas as a reducing agent, without the addition of additional acid. This condition was chosen as the initial baseline because it would provide a point of comparison for previously completed reductive leaching tests on cobalt concentrate materials. All tests were performed at a 5% solids concentration. The 5% solids concentration was chosen to conserve sample mass and to achieve a total metal concentration of approximately 0.2 M in the final solution. A 0.2 M metal concentration was chosen as the target for subsequent NMC precipitation operations. Full experimental details of the tests performed are provided in Table 8. [surface] [8] Overview of Experimental Conditions [Sample ID] [SO, 2, ] [Flow rate (ml / min)] BMJ-A 43 BMJ-B 26 BMC 18 BMK 31

[0291] The leaching extent and pH profile over time during the tests, as summarized in Table 7, are presented in Figures 6a-6d. Comparing these results, it is evident that BMJ-B outperforms the other tested samples. BMJ-B is inherently highly amorphous, resulting in significantly higher reactivity compared to more crystalline samples. The inventors believe this is likely due to lithium removal from the sample. This delithiation of the material disrupts the crystal structure, making the sample amorphous. This produces much faster kinetics, achieving a cobalt recovery of over 90% within five hours. The Canadian sample (BMC) contained most impurities and underwent minimal preprocessing of all samples. Similar BMC was performed for cobalt recovery, but only a 75% nickel recovery was achieved. The inventors believe that the improved performance of this sample is expected to be due to the higher concentration of metallic impurities (Al, Cu, and Fe metals), which act as reducing agents, thereby improving the recovery rate. Both BMJ-A and the Korean sample (BMK) were pure and highly crystalline, and both achieved only 50% recovery for Ni, Co, and Mn within 5 hours. Therefore, BMK was chosen as the representative sample for all other tests because it had sufficient sample quality and was of similar leaching difficulty for most samples. The most difficult sample was chosen because if this material could be leached, all the black blocky samples should be leached under similar conditions. Results - Effect of reagent dosage rate

[0292] Five experiments were conducted to investigate the effect of reagent addition rate. All samples were tested using BMK solid at 55°C and a 5% solid concentration. SO₂ and acid (20% H₂SO₄) were then added to the reactor according to Table 9. For continuous acid testing, the acid was added via a peristaltic pump. [surface] [9] Overview of Experimental Conditions [experiment] [SO, 2, ] [Flow rate (ml / min)] [H, 2, SO, 4, ] [Flow rate] Gradually add acid 31 Add to the sample site until pH < 4.5. Slow and continuous 31 1 ml / min (20% acid) Fast continuous 52 2.2 ml / min (20% acid) Add acid immediately 220 100% acid demand at time 0:00 Add only acid 0 1 ml / min (20% acid)

[0293] The solutions recovered from the tests summarized in Table 9 are presented in Figures 7a-7d. Comparing Figures 7a-7d with Figure 6d, the addition of H₂SO₄ at any volume resulted in a significant improvement in recovery and kinetics.

[0294] The gradual addition of acid with 100% stoichiometry of SO₂ over 2.5 hours (Figure 7a) increased the recovery from 50% over five hours to over 80% over five hours. For this experiment, including the sixth hour, a large dose of acid was added to bring the pH below 3. An immediate spike (5%) was observed in the Co and Ni recoveries. In this final hour, the recovery of all target metals increased to a maximum of 90%, indicating that the system was still acid-limited.

[0295] In the slow, continuous acid test (Figure 7b), acid was fed via a peristaltic pump to deliver 100% stoichiometric acid demand over 200 minutes and 100% stoichiometric SO₂ over 2.5 hours. This test resulted in over 90% recovery of the target metal within 180 minutes. The recovery rate did not change significantly thereafter, indicating the reaction was complete. It should be noted that this recovery rate is based on solution assays, and analysis of the solids indicates that the actual recovery rate of this test is higher than 98%. Therefore, the leaching extent shown in the graph is underestimated, as the head calculations from the final solution and final solids analyses should be more accurate.

[0296] In the rapid continuous test (Fig. 7c), the acid flow rate and SO₂ addition were increased to supply 100% of the stoichiometric requirements within 90 minutes. It was found that approximately 100% of all target metals were extracted within 90 minutes under these conditions. Although there was minimal change in target metal recovery after this point, impurity elements continued to be recovered. At 90 minutes, 40% aluminum and 10% iron were recovered to the solution, increasing to 60% and 15% respectively after 2.5 hours. This demonstrates that there is no benefit in further increasing the reaction time beyond the time required to produce 100% of the reagent. Comparing the impurity recovery in this test (Fig. 7c) with the slow acid test (Fig. 7b) reveals some increase in selectivity at the slower addition rate. Maximum recovery was achieved at a slow rate within 150 minutes. At this point, only 10% Al and 2% Fe were recovered. Comparing this with the rapid addition at 90 minutes shows an approximately 6-fold increase in impurity recovery.

[0297] Figure 7d shows the results of the immediate acid test. In this experiment, 100% of the stoichiometric acid requirement was added at the start of the experiment, with the stoichiometric addition of SO₂ achieved within 30 minutes. It was found that adding all the acid was sufficient to recover 35-40% of Ni, Mn, and Co, and 90% of Li. For all metals, these recoveries increased to above 90% within 30 minutes. After 30 minutes, over a 2.5-hour reaction time, all target metals slowly decreased to 85-90% recovery. At 60 minutes, nickel experienced a sharp decline. This is believed to be an outlier due to dilution error. Aluminum was rapidly recovered to 60% after acid addition, and this value gradually increased over time to a maximum of 78%. Iron recovery remained constant at 10-11% after acid recovery. This demonstrates selectivity roughly equivalent to that of a rapid continuous acid test, but with significantly increasing kinetics.

[0298] The final test (reference example) was performed using only acid and without SO2 (Figure 7e). It was found that after five hours, only 30-40% of Ni, Mn, and Co were recovered, and 80% of Li was recovered. These results correspond to the recoveries achieved in the acid test immediately before the addition of SO2. This demonstrates that, for the BMK sample, approximately 40% of Ni, Mn, and Co are soluble in the absence of a reducing agent. Results - Effect of solid concentration

[0299] An experiment was conducted to investigate the effect of higher solids concentration on the extent and kinetics of the reaction. A higher solids concentration was chosen because it would produce a more concentrated leaching solution. Given a set of yields, this would increase the efficiency of downstream impurity separation and reduce the required reactor volume. In this test, BMK solids were reacted at 55°C with a 20% solids concentration. Acid was added continuously under conditions similar to those in the rapid continuous acid test (2.9 ml / min 50% H₂SO₄, 290 ml / min SO₂). 50% H₂SO₄ was used in this experiment to prevent overflow from the reactor. This higher acid strength caused overheating of the solution, with the temperature rising to approximately 75°C in the first half hour. After this, the reactor was repositioned to a cooling water bath, and the temperature was kept constant at approximately 45°C. As a result, the effects of solids concentration and temperature cannot be completely deconvoluted and must be taken into account when interpreting the results.

[0300] Figure 8 shows the results of the experiment conducted under rapid, continuous reagent conditions with 20% solids. It was found that the overall recovery and reaction kinetics were lower compared to the equivalent test with 5% solids, reaching only 80% recovery after two hours. However, the recovery tended to increase when the experiment had to be terminated, and therefore complete dissolution with 20% solids was expected to be possible. Results - Effect of reaction temperature

[0301] Two experiments were conducted to investigate the effect of temperature on the extent and kinetics of the reaction. Higher temperatures were investigated in an attempt to further improve the reaction kinetics by increasing the dissolution rate. BMK solid was reacted at 75°C with a 5% solid concentration. Acid was added continuously under conditions similar to the rapid continuous acid test (2.2 ml / min 20% H₂SO₄, 52 ml / min SO₂). Note that values ​​exceeding 100% are shown in Figure 9a but are most likely attributable to evaporation. Due to errors in recording mass experimentally, it is impossible to estimate the mass loss attributable to evaporation.

[0302] The study investigated low temperatures in an attempt to further refine the reaction kinetics by increasing the solubility of SO₂ gas in solution. BMK solid reacted at room temperature with a 5% solid concentration. During the experiment, the temperature naturally increased to between 30°C and 35°C. Acid was added continuously under conditions similar to those used in rapid continuous acid testing (2.2 ml / min 20% H₂SO₄, 52 ml / min SO₂). Note that values ​​exceeding 100% are shown in Figure 9b but are most likely attributable to evaporation. Due to errors in recording mass experimentally, it is impossible to estimate the mass loss attributable to evaporation.

[0303] As shown in Figure 9a, increasing the reaction temperature leads to a decrease in efficiency compared to the equivalent test at 55°C. At 75°C, recovery, selectivity, and kinetics are all adversely affected by the increase in reaction temperature. The inventors believe this is likely due to the reduced solubility of SO₂, resulting in slower metal reduction. Similarly, decreasing the reaction temperature also has an adverse effect on recovery and kinetics. At 35°C, a reaction time of 120-150 minutes is required to achieve a recovery rate of over 90% for all target metals. [, precipitation , ] [, , ] Removal of impurities by ion exchange (IX)

[0304] The feed solution having the composition described below is contacted with Lewatit® VP OC 1026 macroporous ion exchange resin (based on a styrene-divinylbenzene copolymer containing di-2-ethylhexyl phosphate (D2EHPA); the resin is available from Lanxess, Cologne). Al Ca Co Cu Fe Mg Mn Na Ni Zn Concentration (mg / L) 4.9 8.3 6,357 1.8 0 54.1 7,992 63.7 9,853 38.9

[0305] Contact with the ion exchange resin was carried out in two stages at 40°C. pH control was performed prior to the IX contact using 0.1 MH H₂SO₄ and 1 M NaOH, with a target pH of 3.8–3.9. The resin was washed with 10% H₂SO₄ acid and subsequently adjusted to pH 3.5 before use. Additives listed below are given on a per-resin-volume basis, taking into account mass variations during washing. 1. Add 250 mL of filtrate to the bottle and lower the controlled pH to 3.9. 2. Add 120 mL of resin, seal the bottle, and place it in a roller bottle at 40°C for 24 hours. 3. Filter out the resin and add the solution to a clean bottle. 4. Adjust the pH to a maximum of 3.8. 5. Add 120 mL of resin, seal the bottle, and place it in a roller bottle at 40°C for 4 hours. 6. Filter out the resin and recover the solution.

[0306] Based on previous ion exchange (IX) tests, two consecutive contacts were selected at 40°C with minimal pH control to maximize Zn removal and minimize Mn loss. Tables 10 and 11 show the solution analysis results before and after each contact. Dilution correction analysis considers the solution retained in the resin during washing and conditioning. Compared to the previous experiments, both contacts showed excellent Zn removal rates (87% and 91%), while Mn loss was not completely mitigated (15% and 16%). Some Al and Ca were also removed (accumulating 29% and 32%, respectively), with Fe entering IX at <1 mg / L. [surface]

[10] [:] Concentration of various metals during ion exchange treatment pH Al Ca Co Cu Mg Mn Na Ni Zn mg / L Before the first IX 3.89 6 11 7,088 2 67 8,937 71 11,450 43 After the first IX (Dilution Correction) 1.67 5 9 7,163 2 68 7,640 72 11,198 6 Before the 2nd IX 3.80 5 8 6,400 2 60 6,803 1,161 9,972 5 After the 2nd IX (Dilution Correction) 1.86 4 7 6,365 2 61 5,712 1,176 9,891 0.4 After the second IX (actual) 1.86 4 6 5,850 2 56 5,250 1,081 9,090 0.4 [surface]

[11] [:] Ion exchange results, percentages of various metals on the resin. % on resin Al Ca Co Cu Mg Mn Na Ni S Zn 1st IX 18% 17% 0% 2% 0% 15% 0% 2% 0% 87% 2nd IX 12% 18% 1% 0% 0% 16% 0% 1% 1% 91% build up 29% 32% 1% 0% 0% 28% 0% 3% 1% 99%

[0307] Removes impurities from feed solution

[0308] This study outlines the removal of impurities from a synthetic solution. A synthetic solution was used to ensure reproducibility and sufficient sample volume. This solution was generated to simulate the solution concentration and pH of solutions produced during leaching. The primary parameters investigated in this report are pH and alkali type.

[0309] This indicates that by increasing the pH to 6.2, 100% of aluminum, copper, chromium, iron, and zinc impurities can be removed from the solution. It has been found that at pH 5–5.5, all aluminum, chromium, and iron, as well as most copper, are removed. Zinc does not precipitate significantly up to pH 6, at which pH 95% of zinc and all remaining copper are lost. Increasing the pH to 6.2 removes the remaining zinc, thus producing a solution free of impurities (except Ca and Mg). A pH of 6.2 is required to achieve the calculated solution specifications. Increasing the pH to 6.2 results in the loss of approximately 25% Ni, 15% Co, and 10% Mn.

[0310] Three different alkalis were tested. Sodium hydroxide and sodium carbonate produced almost identical results. All impurities precipitated at the same pH, and the loss of the target metal was consistent for both alkalis. However, sodium carbonate provided significantly better filtration characteristics for the resulting solids. A combination of manganese carbonate and basic nickel carbonate produced similar results to sodium carbonate. However, it was found that the manganese carbonate did not dissolve completely, resulting in manganese waste. For this reason, sodium carbonate is recommended as the alkali for removing impurities.

[0311] There are significant opportunities for impurity removal in two stages. First, at pH 5.5, most solution impurities can be removed. This solid material can then be separated from the solution and disposed of as waste. The excellent filtration properties of carbonate solids make rapid and easy separation of the solid feasible. After this stage, the purified solution should contain only trace amounts of copper and zinc as impurities. Raising the pH above 6 (ideally to 6.2) will allow the remaining copper and zinc to be discharged from the solution. This will also result in the loss of nickel, cobalt, and manganese, thus depriving this solid of high value. This material can be collected and returned to SAL leaching to recover copper and remove zinc impurities from the system. This concept was demonstrated on a laboratory scale by including solid / liquid separation between the two desired pH levels (5.5 and 6.2). It has been found that by including solid-liquid separation, the loss rates of cobalt, nickel, and manganese can be limited to 5%, 10%, and 0%, respectively.

[0312] The results presented in this paper highlight the potential for eliminating the need for ion exchange in this process. The results of this experiment demonstrate that high-purity solutions can be produced solely through precipitation, thus eliminating the need for expensive ion exchange processes. [introduce]

[0313] Based on the known pH dependence of the solubility of metal hydroxides, it is considered possible to selectively remove hydroxides from solution. The impurities considered are iron, aluminum, copper, and calcium. However, analysis of black, lumpy samples has shown that they may include magnesium and zinc. The testing parameters used in this work are pH and type of alkali. [Materials and Methods] [Material]

[0314] The reagents used in this work are all reagent-grade except for food-grade SO2. The chemicals used in the stock solutions and their target concentrations are shown in Table 12. [surface]

[12] [:Stock solution concentration] [] [Chemical substances used] [Target metal concentration] [(g / l)] NiSO₄·6H₂O 15 CoSO4·7H2O 5 MnSO4·H2O 5 Li₂SO₄ 3 Al₂(SO₄)₃·16H₂O 0.5 FeSO4·7H2O 0.5 CuSO4·5H2O 0.5 CaSO4 0.2 ZnSO4·7H2O 0.2 MgSO4·7H2O 0.2 CrCl 3.6H 2O 0.05 SO 2 saturation H₂SO₄ Adjust pH NaOH Adjust pH

[0315] The solution concentration was selected to represent the solution produced by leaching the black lumps. Impurity elements were added to simulate higher-than-expected impurity concentrations. The pH was initially lowered to the target value of 1. This was exceeded to approximately pH 0.5. However, this initial pH was too low and caused volume problems during precipitation tests. To address this, NaOH was used to raise the pH to 2.6. SO₂ was then bubbled into the reactor until the solution was saturated to better simulate the solution produced during leaching. After this, the pH was again raised to 2.6. [equipment]

[0316] All reactions were carried out in a 1.1 L glass reactor with baffles. Temperature was maintained by a hot plate with thermocouple feedback control. Agitation was achieved using a top-mounted stirrer set to 800 RPM with a high-shear Teflon impeller. The gas addition rate was controlled by bubbling the gas using a glass bubbler connected to a gas flow meter. Care was taken to ensure the bubbler was submerged at a constant level consistent with the impeller blades to ensure maximum gas dispersion during the reaction. pH was controlled using a Methrohm automatic titrator connected to a high-temperature pH probe, and the PID program was run via a connected laptop computer. [method]

[0317] First, the required amount of the stock synthesis solution is weighed directly into the reactor, and the reactor is heated to the reaction temperature. Once at the reaction temperature, the initial sample is obtained and cooled to room temperature in a sealed syringe. After cooling, the sample is filtered through the syringe and diluted in nitric acid, allowing excess sample to return to the reactor. Air bubbling is then performed, and the titrator tubing is inserted into the reactor to begin reagent dosing and timing. Samples are obtained at predetermined experimental time intervals following the same sample handling method.

[0318] After the experiment, the reactor was weighed and the slurry was centrifuged for hydroxide samples or vacuum filtered for carbonate samples. The wet solids were then dried overnight at 105°C and the solution was stored in glass vials. Density readings were obtained before and after the reaction.

[0319] To determine whether the experiment successfully achieved the desired solution purity, a set of target solution concentrations were calculated. These targets are presented in Table 13 and were calculated under the assumption of 100% transfer to the final precipitated NMC product. [surface]

[13] [:] [Target solution concentration] [. *] [Based on assumptions] [] Al * Cr* Cu Fe Zn* NMC Specification 50 10 50 50 50 Target solution with 5% solids in leaching 3.2 0.6 3.2 3.2 3.2 Target solution with 10% solids in leaching 6.7 1.3 6.7 6.7 6.7 Target solution with 25% solids in leaching 20.1 4.0 20.1 20.1 20.1 [result] [] [pH] [Influence] [Testing conditions and reasons]

[0320] pH is a key parameter for determining the separation efficiency of impurity elements from target metals. To investigate the effect of pH, an automatic titrator was used to add alkali (2.5 M NaOH) to a stock solution to maintain the solution at the target pH. Once the target pH was reached and maintained at this pH for 1 hour, a sample was obtained. After a second sample, the pH controller was adjusted to the next level, and the process was repeated. The temperature was maintained at a constant 75°C throughout all experiments. Three experiments were conducted in this manner, and the results of the most conclusive tests are reported here, while other results are referenced for specific points. [Results and Discussion]

[0321] Based on visual observation and the trends of alkali dosage and pH, the first precipitation begins to appear at pH 3.6-4. After maintaining the solution at pH 4 for one hour, more than 90% of Fe and almost all of Al and Cr are removed from the solution. Further increasing the pH to 5 completely removes Fe, Al, and Cr, and removes 65% of Cu impurities. To completely remove Cu, the solution must be increased to pH 6, at which point 94% of Zn is also removed. To meet the zinc solution specifications outlined in Table 11, the pH must be increased to 6.2. However, at pH 6.2, there is a associated loss of 11% cobalt, 21% nickel, and 7% manganese. Increasing the pH above this point results in a loss of more than 90% of nickel, 80% of cobalt, and 40% of manganese. It is evident that the main pH buffer occurs at approximately pH 6.4. Therefore, this represents the upper limit that should never be exceeded to minimize the loss of the target metal.

[0322] Furthermore, it was revealed that rapid alkali addition up to pH 5 caused increased nickel loss at lower pH levels. With rapid alkali addition, 15% of nickel co-precipitated with impurity elements. Therefore, it is recommended to slowly increase the pH over a period of 2 hours to pH 5.5. This should be maintained for 1 hour to maximize copper precipitation. The solution should then be raised to pH 6.2 and immediately separated from the solution. This is based on the observation that at this point, zinc and copper specifications are met, and further maintaining pH 6.2 only increases the loss of nickel, cobalt, and manganese. [The Influence of Base Type] [Testing conditions and reasons]

[0323] Using a method similar to that described in the previous sections, two additional tests were conducted to investigate alternative bases. Sodium carbonate is an ideal candidate to replace NaOH as the base used for impurity removal because it is equally available but generally cheaper to obtain. Furthermore, compared to hydroxides, carbonate anions offer the advantage of allowing for the removal of additional impurities.

[0324] The second alternative base studied was a combination of sodium carbonate with solid manganese carbonate and basic nickel carbonate (BNC). These chemicals are cheaper and may be available on-site, representing an opportunity to reduce reagent costs. For this test, a certain amount of manganese carbonate and BNC were added as solids so that the final solution after impurity removal would have a 6:4:2 Ni:Mn:Co ratio to reflect the continued development in the NMC precipitation unit. This represents the theoretical maximum amount of these compounds that should be added, as there is no need to prepare expensive cobalt salts. The metal salts were added at time 0 and a 1-hour reaction was allowed. After this time, sodium carbonate was added to further adjust the pH according to other experiments. [Results and Discussion]

[0325] A comparison of the results shown in Figures 14 and 15 with those of NaOH reveals no significant differences between the two bases. Table 14 presents a comparison of the key considerations between the two bases. This demonstrates that when using Na₂CO₃, compared to NaOH, impurity elements are removed at the same stage. Even the amount of target metal loss after precipitation is consistent. Therefore, it can be inferred that precipitation occurs due to increased pH and that carbonate anions do not improve precipitation. However, it is noteworthy that Na₂CO₃ exhibits a significant advantage in material processing. The settling and filtration of solids formed during carbonate precipitation are significantly easier than those produced by hydroxide precipitation. [surface]

[14] [:] [NaOH] [and] [Na, 2, CO, 3, ] [Comparison of bases] [.] [List the satisfied tables]

[11] [For all specifications of time points] [pH] [value] NaOH Na₂CO₃ Al pH 5-5.5 5-5.5 Cr pH 5 5 Cu pH 6 6 Fe pH 5 5 Zn pH 6.2 6.2 Co loss 11-17% 12-19% Ni loss 21-31% 20-28% Mn loss 7-11% 6-12%

[0326] Compared to Na₂CO₃ alone, the addition of MnCO₃ and BNC yielded no benefit (see Figures 16 and 17). Impurity removal was achieved at the same pH and level. However, it should be noted that MnCO₃ was not completely dissolved, indicating that its ability to act as a base under these conditions is limited. The dissolution of BNC resulted in a nickel recovery rate greater than 100%, indicating that the assumption that BNC exists in tetrahydrate form is incorrect. It can be assumed that all BNC is dissolved and that theoretically, such molar ratios allow for the addition of additional nickel to the system prior to NMC precipitation; in this case, BNC can be used as a base. [The Impact of Two-Stage Settlement]

[0327] Based on the results of Na₂CO₃ and NaOH precipitation experiments, it appears possible to split this unit into two operations at two different pH levels. By first precipitating at pH 5.5, all Al, Cr, and Fe, as well as approximately 90% and 10% of Cu and Zn, respectively, can be removed. This can be achieved with minimal loss of the target metals. Afterward, solid-liquid separation can be used to remove unwanted low-value waste. The solution can then be raised to pH 6.2, where residual Cu and Zn can be removed. This is accompanied by a loss of approximately 30% of Ni, 20% of Co, and 10% of Mn. This material is of high value and can be collected and recycled to earlier stages of the process.

[0328] To test this concept, an experiment was conducted in which the pH was slowly raised to 5.5 using a 200 g / L Na₂CO₃ solution over a period of approximately 1.5 hours. This pH was then maintained for 1 hour, followed by vacuum filtration. The solution was then heated to clean it and the alkali addition was resumed to achieve a pH of 6.2. This was maintained for 1 hour, followed by final solid / liquid separation. [Results and Discussion]

[0329] Compared to the expected results, significantly less material was observed to precipitate at pH 6.2 when solid / liquid separation was completed between the two stages. The results presented in Figures 18 and 19 support this observation. These results clearly demonstrate that solid / liquid separation significantly improves the retention of Ni, Co, and Mn without compromising impurity removal. The results of this test relative to the single-stage Na₂CO₃ test are shown in Table 15. [surface]

[15] [:] [NaOH] [and] [Na, 2, CO, 3, ] [Comparison of bases] [.] [List the satisfied tables]

[11] [For all specifications of time points] [pH] [value] Na₂CO₃ Na₂CO₃, stage 32 Al pH 5-5.5 5.5 Cr pH 5 5.5 Cu pH 6 6.2 Fe pH 5 5.5 Zn pH 6.2 6.2 Co loss 12-19% 5% Ni loss 20-28% 9% Mn loss 6-12% 0% Formation of coprecipitates

[0330] The purpose of this experiment was to investigate the precipitation of NMC precursors and impurities as pH varied. The goal was to identify suitable pH ranges and solution conditions in which the NMC precursor could precipitate to obtain suitable major chemical elements (Ni / Co / Mn) while exhibiting selectivity for impurities Ca and Mg. It was found that in a weakly alkaline pH range (pH 7.6-8.0), most impurity ions (Ca²⁺ and Mg²⁺) would not co-precipitate with the NMC precursor. These results indicate that this method is feasible for generating NMC precursors by adjusting the initial NMC composition, base type, and amount in the solution. [experiment]

[0331] 500 mL of initial NMC solution (0.2–0.24 M total NMC, see Figure 20 for specific samples) was fed into a 1 L reactor containing 200 mL of ammonium solution (0.1 M) at a rate of 8 mL / min. After 3 minutes, 480 mL of alkali solution (0.20–0.24 M) was pumped into the same reactor at the same flow rate. At the end of 60 minutes, all residual liquid was aspirated into the reactor. A heating plate was used to heat the reactor to 80°C in an inert gas (N₂) atmosphere. During the pumping of transition metals and alkali solution (1 hour), vigorous mixing was performed in the 1 L reactor using a top-mounted mechanical stirrer at 800 rpm. Subsequently, the stirring rate was maintained at 800 rpm for the next 4 hours until 5:00 pm. For safety reasons, the stirring rate was set at 600 rpm for 15–16 hours after several hours. The total settling time was in the range of 20–21 hours. The reactor was then cooled from 80°C to room temperature. The final slurry was filtered by vacuum filtration to obtain the precipitate. The final solution pH of different samples is shown in Figure 20. The obtained precipitate was washed in two stages. The first wash involved re-slurrying the precipitate into a 0.1 M NaOH solution (approximately 5% solids content) using magnetic stirring at 80°C for 60 minutes, followed by solid / liquid separation using a vacuum filter. The second wash involved re-slurrying the precipitate from the first wash into a 2% NH3H2O ​​solution (approximately 5% solids content) using magnetic stirring at 80°C for 60 minutes, followed by solid / liquid separation using a vacuum filter to obtain the final NMC precursor solids. Subsequently, the NMC precursor was dried in an oven at 105°C for 8–10 hours to remove free water. After drying, the precipitate was conveyed for the preparation of coin-type battery packs after lithiation. The final NMC proportion in the precursor is shown in Figure 20.

[0332] Except for Sample 8, which was prepared using a true leaching solution, all NMC 44-52 samples were prepared using initial synthetic NMC solutions, in which analytical grade nickel, cobalt, and manganese sulfates were dissolved in DI water. Some of these initial synthetic NMC solutions contained 20 mg / L Ca and 200 mg / L Mg.

[0333] The initial NMC solution contains 0.2–0.24 M total Ni + Co + Mn (NMC). The molar NMC ratio of the initial NMC solution is specified in the Y-axis labels of Figure 20. For example, "NMC 44 (Initial 6.1:1.8:2.1) pH 9.20" in Figure 20 indicates that the initial NMC ratio in this initial NMC solution (NMC 44 sample) is 6.1:1.8:2.1. Furthermore, when precipitation is complete, for "NMC 44 (Initial 6.1:1.8:2.1) pH 9.20" in Figure 20, the final solution pH is 9.20. [Results and Discussion]

[0334] Figure 21 shows that the precipitation of Ca²⁺ and Mg²⁺ (from initial feed solution concentrations of 50 and 200 mg / L, respectively) rapidly increases in the alkaline pH range (8.1–9.3) to a maximum of 88.6% Ca and 71.4% Mg at pH 9.3, while the precipitation percentages of Ca²⁺ (5–18%) and Mg²⁺ (1–3%) remain low at pH < 8.

[0335] Figure 22 shows that when the final pH > 8.6, the precipitation percentages of Ni²⁺, Co²⁺, and Mn²⁺ are very high (98-100%). In the weakly alkaline pH range (8-8.2), the precipitation percentages of Ni²⁺ and Co²⁺ remain very similar in the 90-100% range, while the precipitation percentage of Mn²⁺ is relatively lower than that of Ni²⁺ and Co²⁺, which complicates the precipitation of NMC622 with the appropriate chemical composition. Specifically, when the initial Mn²⁺ concentration increases from CMn = 0.02M (initial 6:2:2) to CMn = 0.04M (initial 6:3:2) and 0.06M (initial 6:4:2), the precipitation percentage of Mn²⁺ decreases from approximately 80% to approximately 70%. In the weakly alkaline pH range (7.6-8.0), the precipitation percentages of Ni²⁺ and Co²⁺ remained similar in the 80-90% range, while the precipitation percentage of Mn²⁺ was approximately 70% at an initial CMn = 0.06M (initial 6:4:2). It should be noted that the initial Mn concentration was varied throughout the test to attempt and achieve the appropriate final Mn concentration in the precipitate.

[0336] There are some outlier data points in the Mn precipitation percentage shown in Figure 22. For example, at pH=7.9 (NMC 52 sample), the Mn²⁺ precipitation percentage reaches 94%, similar to that of Ni²⁺ and Co²⁺. This outlier is attributed to the oxidation of Mn from +2 to +4 by air during the NMC precipitation process without N₂ gas protection (N₂ cylinder depletion). Another repeat test using N₂ gas protection during NMC precipitation (NMC 52-R sample, see Table 10) resulted in approximately 70% Mn²⁺ precipitation at pH=7.87. The results confirm this hypothesis. Further battery pack performance tests for NMC 52 and NMC 52-R reveal that N₂ protection during NMC precipitation is necessary for battery pack performance, as literature indicates that N₂ protection is necessary during NMC precipitation. Other outlier data at pH=7.7 is attributed to leakage in the precipitation reactor.

[0337] The results in Figures 21 and 22 provide guidance on how to prepare initial NMC solutions with high Mn²⁺ concentrations in a weakly alkaline pH range (7.6–8.0) to ultimately obtain coprecipitated NMC precursors with the appropriate composition of commercial products, where the percentages of Ca²⁺ and Mg²⁺ precipitation remain low.

[0338] Figure 20 reveals the relationship between the NMC ratio in the initial solution and the NMC ratio in the final solid at different precipitation pH values. The NMC ratio in the initial solution varies between 6:2:2, 6:3:2, and 6:4:2 because the precipitation percentage of Mn²⁺ is lower than that of Ni²⁺ and Co²⁺ in the slightly alkaline pH range (pH 7.6–8.0), as discussed in Figure 22. For experimental procedures, it is difficult to maintain an accurate NMC ratio initially by using analytical metal sulfates with different hydration numbers. Therefore, the Y-axis in Figure 20 shows the exact initial NMC ratio corresponding to NMC ratios of 6:2:2, 6:3:2, and 6:4:2, sample name, and corresponding final precipitation pH, while the X-axis in Figure 20 shows the final NMC ratio in the solid NMC precursor. The results showed that several NMC precursors were generated, matching the composition of commercial NMC 622, including Sample 8 (pH 9.32), NMC 44 (pH 9.2), NMC 47 (pH 8.63), NMC 37-4 (pH 8.08), and NMC 49 (pH 7.7). Many other NMC precursors were also present, with final NMC ratios matching commercial NMC 532, including NMC 37-2 (pH 8.06), NMC 52 (pH 7.9), and NMC 50 (pH 7.77). Preparation of battery pack materials

[0339] The purified solution from the leaching process was used to precipitate the NMC 622 precursor. Specific NMC co-precipitation conditions are provided in the experimental sections below. Subsequently, the obtained precursor was lithiated and calcined to produce the NMC 622 cathode material. The battery pack performance of this NMC 622 cathode material is comparable to that of commercial NMC 622 cathode materials. [experiment] [-] [NMC] [Precipitation Process]

[0340] Specifically, the leaching solution (Sample 8 - Leaching), the purified solution (Sample 8 - Purified), and the final solution (Sample 8 - Final) from the leaching process are listed in Table 16. To conform to the chemical composition of the NMC 622 precursor, additional Ni and Mn sulfates were added to the purified solution (Sample 8 - Purified) to produce Sample 8 - Final Solution, which is directly used for NMC precipitation. [surface]

[16] [Solution analysis for solutions] [(] [Leaching, purification, and final solution] [)] [] [] [mg / L] [Al] [Ca] [Co] [Cu] [Fe] [K] [Mg] [Mn] [Na] [Ni] [S] [Zn] [sample] [8-] [Leaching] 47.5 3.8 5561 51.2 65.4 8.6 26.7 6958 30.8 10254 16204 137.1 [sample] [8-] [purification] 3.7 6.1 5850 1.9 0 7.5 55.8 5250 1081.1 9090 15123 0.4 [sample] [8-] [final] 3.7 6.1 5850 1.9 0 7.5 55.8 5250 1081.1 9090 15123 0.4

[0341] 500 mL of initial NMC solution (0.2 M total NMC) was fed into a 1 L reactor containing 200 mL of ammonium solution (0.1 M) at a rate of 8 mL / min using a peristaltic pump. At the end of 3 minutes, 480 mL of alkali solution (0.208 M) was aspirated into the same reactor at the same flow rate. At the end of 60 minutes, all liquid was aspirated into the reactor. Mixing was performed in the 1 L reactor using a top-mounted mechanical stirrer at 800 rpm. The reactor was heated to 80 °C under an inert N2 atmosphere using a heating plate. The precipitation residence time was in the range of 8–10 hours.

[0342] The reactor was then cooled from 80°C to room temperature. The final slurry was filtered by vacuum filtration to obtain the precipitate. The final solution pH (or terminal pH) was 9.32. The obtained precipitate underwent a two-stage washing process. The first wash involved re-slurrying the precipitate into a 0.1 M NaOH solution (approximately 5% solids content) using magnetic stirring at 80°C for 60 minutes, followed by solid / liquid separation using a vacuum filter. The second wash involved re-slurrying the precipitate from the first wash into a 2% NH3H2O ​​solution (approximately 5% solids content) using magnetic stirring at 80°C for 60 minutes, followed by solid / liquid separation using a vacuum filter to obtain the final NMC precursor solid. Subsequently, the NMC precursor was dried in an oven at 105°C for 8–10 hours, and it was ready for use in battery pack fabrication. The final NMC ratio in the precursor was 5.8:2.2:2.1, falling within the range of 6:2:2. Analyses are provided in Table 17. [surface]

[17] [:] [Before and after washing] [NMC] [Precursor] [NMC] [Precipitation degree and solids analysis] [(] [Impurity content in parts per million] [(] [ppm] [)] [Measured in units] [;] [Ni] [、] [Co] [、] [Mn] [Content expressed as a percentage by weight] [,] [weight] [%] [Measured in units] [)] [] [Precipitation Concentration] [Al] [Ca] [Co] [Cu] [Fe] [K] [Mg] [Mn] [Na] [Ni] [S] [Zn] [Solution analysis] NMC precipitation level, % n / a 88.64% 100.0% n / a n / a n / a 71.40% 99.93% n / a 99.98% 4.72% n / a [Solid Analysis] Unwashed (Sample 8 - Final) n / a 298.2 10.7% 0 0 0 934.3 12.% 1172.9 31.5% 10735.5 0 First wash (Sample 8 - Final) n / a 337.3 12.5% 0 0 0 1071.4 14.0% 416.6 36.5% 2182.5 0 Second wash (Sample 8 - Final, Final Product) n / a 317.4 12.4% 0 0 0 1051.5 13.8% 357.1 35.9% 1984.1 0 [Finally in solids] [NMC] [Proportion] [5.8:2.2:] [2.1] [] [] [] [] [] [] [] [] [] [result] [-] [Battery Pack Performance]

[0343] The NMC precursor obtained by the aforementioned method was then lithiated to prepare active NMC. The precursor was first mixed with 5% excess stoichiometric amount of Li₂CO₃ as the lithium source. Regarding the calcination process, the mixture was first calcined at a low temperature of 400-500°C for 1 hour, then ground again, and subsequently calcined at a high temperature of 850-900°C for 10 hours in air. The cathode was prepared by dispersing active NMC (80% by weight), carbon black (10% by weight), and polyvinylidene fluoride (10% by weight) in N-methyl-2-pyrrolidone. The slurry was then treated on aluminum foil and subsequently dried at 100°C for 24 hours. The electrolyte used was EC / DMC containing LiPF₆ (1 M) (mass ratio 1:1). The batteries were then encapsulated in an argon-filled glove box using lithium metal anodes, and the electrochemical performance of these batteries was tested within a voltage range of 3.0-4.4 V.

[0344] The battery pack performance of the cathode of Sample 8 at 0.2 C showed an initial specific capacity of approximately 163 mAh / g (baseline: 170 mAh / g), and the capacity remained greater than 163 after 6 cycles, as shown in Table 18. The battery pack performance is comparable to commercial NMC 622 battery packs, which have capacities in the range of 165-170 mAh / g at the same charge / discharge rates. The cathode of the sample also exhibited a well-defined crystalline structure with hexagonal arrangement and low Ni-Li mixing. [surface]

[18] [:] [exist] [0] [.] [2] [] [C] [Sample used below] [8] [Battery pack performance of the three individual battery packs at the cathode] [] [sample] [\] [cycle] [1] [2] [3] [4] [5] [6] [8-] [Battery Pack] [1] 161.8 163.5 161.1 163.2 162.3 162.1 [8-] [Battery Pack] [2] 162.7 163.8 163.6 163.7 164.7 164.2 [8-] [Battery Pack] [3] 164.8 166.1 163.6 164.4 163.2 162.6 [average] 163.1 164.5 162.8 163.8 163.4 163.0 [, Example , ] [, 3 , ] [, : Precipitation in the presence of impurities

[0345] In the presence of a wide range of impurities, mixed precipitates containing nickel, manganese, and cobalt (NMC) are generated from various solutions. The method employed avoids the precipitation of some or all of the impurities of this invention, and produces coprecipitates with electrochemical properties despite the presence of these impurities in the initial solution.

[0346] Table 19-32 presents the co-precipitation ratios of aqueous feed solutions and supernatants following a series of NMC precipitation tests. In interpreting these values, it should be noted that they are NMC:impurities ratios, and therefore, the smaller the value, the higher the impurity content relative to NMC. Thus, a decrease in the ratio after precipitation demonstrates selectivity. The results shown in the table therefore demonstrate selectivity for individual elements. [, , ] [surface]

[19] Al Test ID initial ratio Final ratio Test 3 13521 1861 Test 4 12134 122 Test 5 5190 60 Test 6 354598 11630 Test 7 51189 16121 Test 9 218.775 182 [surface]

[20] Ca Test ID initial ratio Final ratio Test 2 192 94 Test 3 260 85 Test 4 258 10 Test 5 1269 9 Test 6 87 4 Test 7 138 59 Test 8 292 111 Test 9 141 9 Test 10 132 5 [surface] [twenty one] B Test ID initial ratio Final ratio Test 6 39400 1454 Test 8 2651 955 Test 9 3282 130 [surface] [twenty two] Cr Test ID initial ratio Final ratio Test 6 39400 11630 Test 7 25595 16121 [surface] [twenty three] Cu Test ID initial ratio Final ratio Test 1 15412.4286 14572 Test 2 898.6875 8396 Test 3 1502.33333 232.625 Test 4 6067 122 [surface] [twenty four] Fe Test ID initial ratio Final ratio Test 3 6760.5 930.5 Test 4 12134 122 Test 7 51189 16121 [surface]

[25] K Test ID initial ratio Final ratio Test 1 35962.3 1821.5 Test 2 845.8 839.6 Test 5 1427.1 5.8 Test 8 171.4 61.9 Test 9 3.3 0.1 Test 10 1712.7 6.6 [surface]

[26] Li Test ID initial ratio Final ratio Test 8 8615 3341 Test 10 7.96 0.30 [surface]

[27] Mg Test ID initial ratio Final ratio Test 1 53944 14572 Test 2 65 19 Test 3 60 19 Test 4 56 1 Test 5 601 9 Test 6 35 1 Test 7 51 20 Test 8 0.2 0.1 Test 9 53 2 Test 10 133 5 [surface]

[28] Na Test ID initial ratio Final ratio Test 2 138.3 2.1 Test 3 139.4 0.8 Test 4 181.1 0.0 Test 5 2.9 0.0 Test 6 555.8 0.1 Test 7 1137.5 0.9 Test 9 354.8 0.1 Test 10 5.3 0.0 [surface]

[29] P Test ID initial ratio Final ratio Test 7 12797.3 2303.0 Test 9 1381.7 20.6 [surface]

[30] Pb Test ID initial ratio Final ratio Test 2 14379 8396 Test 10 2570 90 [] [surface]

[31] Si Test ID initial ratio Final ratio Test 6 4488.6 505.7 Test 7 2132.9 1074.7 Test 9 1640.8 56.8 [surface]

[32] S Test ID initial ratio Final ratio Test 1 1.69 0.52 Test 2 1.71 0.51 Test 3 1.76 0.58 Test 4 1.70 0.04 Test 5 1.19 0.00 Test 9 1.45 0.06 Test 10 0.76 0.03

[0347] Table 33 shows the concentrations (in NMC:element ratio) of aqueous feed solutions (i.e., prior to coprecipitation) with a wide range of elements. This table also includes battery pack tests demonstrating that these solutions can produce acceptable coprecipitates through electrochemical performance. [surface]

[33] sample name test 1 2 3 4 5 6 7 8 9 10 Ag 74035 13127 Al 8299 7190 13521 12134 2854 444210 51189 219 As 148070 3282 Ba B 49357 3413 2651 3282 Bi 222105 51189 Ca 192 260 258 1269 108 138 292 141 132 Cd 74 Cr 12134 16310 49357 25595 215 Cu 15412 899 1502 6067 114170 31 Feb 1598 6761 12134 51189 34460 60 K 35962 846 15023 1427 171 3 1712 Li 14379 135210 8615 8 Mg 53944 65 60 56 601 43 51 0 53 133 Mo 444210 So 138 139 181 3 696 1138 355 5 P 107887 13521 11417 12797 11487 1382 2570 Pb 107887 14379 12134 12692 10238 17230 2387 Sb 148070 26253 See 11105 10238 34460 6563 Si 5623 2133 204 1641 Sn 14807 10238 34460 13127 S 2 2 2 2 1 2 2 0.1 1 1 Ti 14379 V 444210 205 W 444210 Zn 7190 11417 111053 3829 2569 Zr 142 Initial battery pack capacity (mAh / g) 177 164 131 138 161 163 141 75 95 128 [, Example , ] [, 4 , ] [, : Business scale

[0348] The coprecipitation process is demonstrated on a commercial scale. Table 34 details the initial solution concentration (aqueous feed solution concentration) and the relevant ratios for nickel and each of the elements. [surface]

[34] Concentration (mg / l) Ni: element Al 0.4 16522.7 Ca 50.7 133.7 Cd 0.1 112905.0 Co 2006.1 3.4 Cr 0.9 7527.0 Cu 2.1 3256.9 Feb 1.0 6983.8 K 16.9 401.3 Li 52.2 129.7 Mg 348.0 19.5 Mr 5813.7 1.2 So 16742.6 0.4 Ni 6774.3 1.0 Q 10.5 646.4 Pb 4.3 1575.4 S 21155.8 0.3 Zn 12.9 527.2

[0349] This solution uses a substoichiometric volume of sodium carbonate as a precipitant for co-precipitation. A substoichiometric amount of alkali is used to prevent most of the Ca and Mg from precipitating during this process. This method results in Ni, Mn, and Co precipitation of 95%, 80%, and 95%, respectively. Therefore, an additional amount of Mn must be included in the starting solution to produce materials that meet specifications.

[0350] The coprecipitate from this process is subjected to a series of water and alkali washing steps to remove Na and S. The final mother liquor and the analysis of the washed solids are shown in Table 35. [surface]

[35] Final solution (mother liquor) concentration (mg / L) Final solids concentration (ppm) Moisture% 64.9 Al 0.4 0.9 As Ca 20.1 65.8 Cd 0.1 1.7 Co 197.4 34747.8 Cr 0.5 1.8 Cu 1.1 13.1 Fe 1.3 9.4 K 129.9 0.0 Li 6.5 0.0 Mg 123.9 131.6 Mn 638.8 36097.2 Na 13606.5 86.7 Ni 453.3 112718.0 P 13.1 13.7 Pb 2.6 1.8 S 11698.2 307.9 Sc Zn 3.9

[0351] Based on these final solution and solid compositions, a clear separation can be observed between NMC and impurity elements (such as Ca, Mg, Al, Cu, Cr, Fe, K, Na, P, and S). This result, demonstrated on an industrial scale, highlights a method detailed in the patent for precipitating NMC in the presence of impurities, the precipitation being selective for NMC relative to some or all of the impurity elements. This material is then lithium-ionized, calcined, and used to form a battery pack. This battery pack exhibits electrochemical performance and achieves an initial capacity of 163 mAh / g. [, Example , ] [, 5 , ] [, : Business scale

[0352] During NMC precipitation, the process described in Example 4 is repeated, including the aging process. Table 36 details the initial concentration and related ratios for nickel. [surface]

[36] Concentration (mg / l) Ni: element Al 0.3 95851.5 As 0.7 44550.7 Ca 498.1 63.5 Cd 0.2 131795.8 Co 10065.6 3.1 Cr 0.5 67300.0 Cu 2.8 11378.1 Feb 0.1 316310.0 K 4.5 7029.1 Li 0.1 316310.0 Mg 1305.8 24.2 Mr 10930.1 2.9 So 20541.9 1.5 Ni 31631.0 1.0 Q 2.4 13403.0 Pb 0.1 316310.0 S Sc 0.1 316310.0 Zn 0.5 67300.0

[0353] This solution was co-precipitated with a stoichiometric amount of alkali and an excess of Mn. At the end of the coprecipitation, the solution was aged in a tank for 48 hours. This has the benefit of redissolving some of the precipitated Mg, thereby increasing the separation efficiency of Mg and Ni. Furthermore, this method also allows for greater control over the degree of precipitation of Mg, which is typically added to NMC products as a dopant to improve cycle stability. The composition of the product produced by this method is shown in Table 37. This material was then lithium-ionized, calcined, and used to form a battery pack for electrochemical testing. The battery pack test yielded an initial capacity of 170 mAh / g. [surface]

[37] Final solids concentration (ppm) [Al] 0 [Ca] 794 [Co] 121825 [Mg] 496 [Mn] 111508 [Na] 60 [Ni] 349603 [S] 1587 [Zn] 198 [, Example , ] [, 6 , ] [, : Processing laterite Ni ore to directly produce NMC Leaching:

[0354] Lateritic nickel ore samples were leached with sulfuric acid to produce solutions suitable for the direct production of NMC precursor materials. Analysis of the materials used is shown in Table 38. The leaching conditions used were 1:1 Mg:H₂SO₄ (in moles), 10% dry solids loading, at 80°C for 6 hours. After leaching, 90% of nickel, 80% of magnesium, and variable impurity elements were recovered into the solution. The recoveries of all major elements are shown in Figure 23, and the composition of the leaching solution is shown in Table 39. [surface] [38 -] [Elemental Composition of Nickel Laterite] [] Element (weight %) Al Ca Co Cr Cu Fe average 0.320 0.083 0.04 0.810 0.004 6.910 Element (weight %%) Mg Mn Ni Si Zn average 19.200 0.108 1.278 19.651 0.011 [surface]

[39] [-] [] [Composition of Laterite Leaching Solution] [] Element (Mg / L) Al Ca Co Cr Cu Fe Mg Mn Ni Si Zn Leaching solution 101 12 40 46 4 4120 16910 95 1272 293 8 Impurity removal:

[0355] Impurities were then removed using the pH of the solution until the level required for selective coprecipitation was reached. This was achieved by heating the filtrate from the previous leaching step and raising the pH using a sodium carbonate solution. Air was bubbled into the reactor to oxidize the iron, causing it to precipitate as ferric iron. For this case, a single-state solution was insufficient, so 30% H₂O₂ was used as the oxidant in the second step. After this, the solid was separated from the purified solution. The experimental conditions used were: 75°C, pH 5.5, held for 1 hour, 200 g / L Na₂CO₃ as the base, and the addition of air and 30% H₂O₂ as the oxidant in stage 2. The composition of the final purified solution is shown in Table 40. [surface]

[40] [-] [Composition of the purified solution] [] Element (Mg / L) Al Ca Co Cr Cu Fe Mg Mn Ni Zn Purified solution 0.3 12.4 28.5 0 0.1 2.4 15380 75.5 677.9 1.7 NMC coprecipitation:

[0356] Prior to NMC precipitation, the Ni concentration was increased to 2 g / L and the cobalt and manganese concentrations were adjusted to achieve a Ni:Mn:Co molar ratio of 6:4:2. This ratio was adjusted using sulfate. NMC precipitation was completed according to the following procedure: 15% Na₂CO₃ was added for 36 hours, followed by overnight incubation. This was repeated a second time; 75°C; final pH 7.39. The solution concentrations of the major elements before and after this method are shown in Table 41. [surface]

[41] [] [-] [NMC] [Solution concentration before and after precipitation] [] Element (Mg / L) Ca Co Mg Mn Ni The adjusted solution before precipitation 11.8 542 15150 744 2160 The final solution after coprecipitation 12 357 16710 59.2 920

[0357] The coprecipitate was washed using a three-step washing method, including water washing, water reslurry washing, sodium hydroxide reslurry washing, and weak ammonia washing. The overall recovery rates of each major element after the process are shown in Figure 24. The composition of the final solids produced is shown in Table 42. These results clearly demonstrate a high selectivity for Ca / Mg NMC, even when the Mg concentration is significantly higher than that of the NMC metal. This allows low-grade sources of NMC metal (such as laterite) to be used directly in the production of NMC. [surface]

[42] [-] [NMC] [Solution concentration before and after coprecipitation] [] Element (weight %) Ca Co Mg Mn Ni Final washed solids 0.03% 11.90% 0.05% 11.85% 42.81% Battery pack test results:

[0358] Three cathodes were prepared from the NMC coprecipitate sample. The initial capacity was 75 mAh / g, which was maintained at 84% after 20 cycles. [, Example , ] [, 7 , ] [, : Processing mixed sulfide minerals to directly produce NMC Leaching:

[0359] Sulfide concentrate samples were leached with sulfuric acid and air to produce solutions suitable for the direct production of NMC precursor materials. The analysis of the materials used is shown in Table 43. The experimental conditions used were: 80°C, 4 days, 10% dry solids loading, H₂SO₄ added to maintain pH 2, and an air flow rate of 0.5 L / min. Following leaching, 30% nickel and variable impurity elements were recovered. The recoveries of all major elements are shown in Figure 25, and the composition of the leaching solution is shown in Table 44. [surface]

[43] [-] [Elemental composition of sulfide concentrate sample] [] Element (weight %) Al Ca Co Cr Cu Fe Sulfide concentrate 0.14% 0.18% 0.39% 0.01% 0.46% 39.90% Element (weight %) Mg Mn Ni Si S Sulfide concentrate 0.22% 0.06% 12.42% 0.18% 20.09% [surface]

[44] [-] [Composition of the leaching solution after sulfuric acid leaching of sulfide concentrate] Element (mg / L) Al Ca Co Cr Cu Fe Leaching solution 72.6 158.9 131.8 0.9 299 6020 Element (mg / L) Mg Mn Ni Si S Leaching solution 205.2 5.1 4656 154.1 7730 Impurity removal:

[0360] Impurities were then removed using the pH of the solution until the required level for selective coprecipitation was achieved. This was accomplished by heating the filtrate from the previous leaching step and raising the pH using a sodium carbonate solution. Air was bubbled into the reactor to oxidize the iron, causing it to precipitate as ferric iron. The experimental conditions used were: 75°C, pH increasing sequentially from 3 to 4 to 5.3 to 6, 200 g / L Na₂CO₃ as the base, and air bubbling as the oxidant. NMC precipitation:

[0361] Prior to NMC precipitation, the Ni concentration was increased and the cobalt and manganese concentrations were adjusted to achieve a Ni:Mn:Co molar ratio of 6:3:2. This ratio was adjusted using high-purity sulfate. NMC precipitation was completed according to the following procedure: 5% Na₂CO₃ was added for 36 hours, followed by overnight incubation at 75°C, with a final pH of 7.85. The solution concentrations before and after this process are shown in Table 45. [, , ] [] [surface]

[45] [-] [NMC] [Solution concentration before and after precipitation] [] Element (Mg / L) Ca Co Mg Mn Ni S The adjusted solution before coprecipitation 104 852 116 1213 2799 44490 The final solution after coprecipitation 99 130 114 795 497.4 44050

[0362] Subsequently, the coprecipitate was washed using a three-step washing method, including water washing, water reslurry washing, sodium hydroxide reslurry washing, and weak ammonia washing. The overall recovery rates of each major element after the process are shown in Figure 26. The composition of the final solids produced is shown in Table 46. [surface]

[46] [-] [Finally washed] [NMC] [Solid Composition of Solids] [] Element (weight %) Ca Co Mg Mn Ni Final washed solids 0.04% 13.45% 0.0% 13.04% 39.9% [, Example , ] [, 8 , ] [, : Examples of leaching of a mixture of cobalt concentrate and black lumps.

[0363] A solution suitable for the direct production of NMC was prepared by leaching a 50% blend of cobalt concentrate and black lumps with SO2. The analysis of the materials used is shown in Table 47. The experimental conditions used were: 55°C, 2 hours 40 minutes, 5% dry solids loading, SO2 bubbling, achieving 200% stoichiometry within 2 hours. After leaching, 30% nickel and variable impurity elements were recovered. The recoveries of all major elements are shown in Figure 27, and the composition of the leaching solution is shown in Table 48. [surface]

[47] [-]

[50] [%] [Cobalt concentrate]

[50] [%] [Elemental composition of the sample containing black lumps] [] Element (weight %) Al Ca Co Cr Cu Mixing 0.2% 0.0% 11.6% 0.0% 0.2% Element (weight %) Fe Mg Mn Ni Zn Mixing 0.3% 0.0% 12.8% 28.2% 0.2% [surface]

[48] [-] [In cobalt concentrate] [ / ] [Composition of the leachate solution after sulfuric acid leaching of the black lumps] [] Element (mg / L) Al Ca Co Cr Cu Leaching solution 27.7 7.1 4104 0 30.9 Element (mg / L) Fe Mg Mn Ni Zn Leaching solution 48.2 4.8 4611 10923 43.5

[0364] Following this, the pH of the solution will be increased to 5.5 by bubbling air. This condition should be maintained for at least one hour to allow sufficient time for Fe to precipitate. This process is intended to remove sufficient amounts of impurities, such as Al, Fe, Cu, Cr, and Zn, to enable selective precipitation. The solution should then be adjusted to a molar ratio of Ni, Mn, and Co of 6:2:2, at which point it will be suitable for the production of NMC. [, Example , ] [, 9 , ] [, : Washing after co-precipitation

[0365] Following coprecipitation, the resulting solids undergo a series of washing processes, which may include water, alkali (carbonate, hydroxide, or ammonia) or acid washing. The specific washing regimen chosen depends on the impurities present. In this example, approximately 1 metric tonne of wet NMC is produced on a commercial scale. This is followed by water washing at a water:dry solids ratio of 60:1 by weight, then caustic soda resizing with 10% sodium hydroxide solution at 7% solids, and finally a final water wash at a water:dry solids ratio of 40:1 by weight. The analysis of this sequential process is shown in Table 49. The washing steps successfully removed some impurity elements and improved the NMC:impurity ratio of impurity elements (such as Ca, Cu, K, Mg, Na, S, and Zn). [surface]

[49] [Moisture] [(%) [Ca] [Co] [Cu] [K] [Li] Unwashed 71.7 122 11170 5 36 1 Water washing 76.4 13 10723 4 0 1 caustic alkali washing 79.6 43 11653 4 10 8 Water washing 77.7 55 11391 5 0 2 [Mg] [Mn] [Na] [Ni] [S] [Zn] Unwashed 508 12206 15027 101992 22919 6 Water washing 45 12400 90 98753 9574 5 caustic alkali washing 60 13426 999 104828 406 4 Water washing 64 13279 105 103858 258 4

[0366] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0367] In this specification and the claims (if any), the word "comprising" and its derivatives, including "containing" and "including", include each of the wholes, but do not exclude the inclusion of one or more other wholes.

[0368] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "in an embodiment" or "in an embodiment" appearing throughout this specification does not necessarily refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in one or more combinations in any suitable manner.

[0369] In accordance with regulations, the invention has been described using language more or less specific to structural or methodological features. It should be understood that the invention is not limited to the specific features shown or described, as the manner described herein includes preferred forms for carrying out the invention. Therefore, the invention is claimed within any of its forms or variations within the appropriate scope of the appended claims (if any) as appropriately interpreted by one of ordinary skill in the art.

[0370] 10: Method 15: Steps 20: Steps 25: Steps 35: Steps 40: Steps 45: Steps 50: Steps 55: Steps 105: Reducing agent 108: Leaching agent 110: Method 115: Steps 120a: Steps 120b: Steps 125a: Steps 125b: Steps 130: Steps 135: Steps 140: Steps 150: Steps 155: Steps 201: Ni / Co / Mn oxide materials 203:Acid 205: Water 207: Oxidizing agent / Reducing agent 210: Leaching container 215: Filter 218: Impurity solids 220: Handling Containers 222: Oxidizing agent 224: Alkali 230: Filter 232: Impurity solids 234: Ni / Co / Mn solution 251: Reduced Ni / Co / Mn materials 253:Acid 255: Water 257: Oxidizing agent / Oxidizing agent 260: Leaching container 265: Filter 268: Impurity solids 270: Handling Containers 272: Reducing agent 274: Alkali 280: Filter 282: Impurity solids 284: Ni / Co / Mn solution

Claims

1. A method for producing a coprecipitate, the method comprising: adjusting the pH of an aqueous feed solution containing at least two metals and an impurity to between about 6.2 and about 11 to provide a coprecipitate and a supernatant; separating the coprecipitate from the supernatant; and washing the coprecipitate with an alkaline detergent, wherein: - the at least two metals are selected from nickel, cobalt, and manganese; - the impurity is selected from at least one of the group consisting of: arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, vanadium, lanthanum, lanthanides, actinium, actinides, titanium, fluorine, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, niobium, and combinations thereof; - in the aqueous feed solution, the mass ratio of the at least two metals to the impurity is less than 50,000:1; - the coprecipitate comprises: o nickel, when present in the aqueous feed solution; o Cobalt, when present in the aqueous feed solution; and manganese, when present in the aqueous feed solution; and the supernatant contains at least one of the impurities, wherein the supernatant contains more than 10 mg / L of nickel, cobalt or manganese.

2. The method of claim 1, wherein the pH of the aqueous feed solution is adjusted to between approximately 6.2 and less than 10.

3. The method of claim 1 or 2, wherein the impurity is selected from at least one of the following groups: arsenic, aluminum, barium, cadmium, carbon, calcium, magnesium, chromium, copper, lead, silicon, vanadium, lanthanum, lanthanides, actinium, actinides, titanium, scandium, iron, zinc, zirconium, silver, tungsten, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, niobium, and combinations thereof.

4. The method of claim 1 or 2, wherein in the aqueous feed solution, the mass ratio of the at least two metals to the impurity is less than 5,000:

1.

5. As in request item 1 or 2, wherein: (i) The molar ratio of the at least two metals to alkaline earth metal impurities in the aqueous feed solution is less than 200:1; or (ii) The molar ratio of the at least two metals to metal and metalloid impurities is less than 500,000:

1.

6. The method of claim 1 or 2, wherein the pH of the aqueous feed solution is adjusted to between approximately 6.2 and 9.

2.

7. The method of claim 1 or 2, wherein the aqueous feed solution comprises cobalt, manganese and nickel.

8. The method of claim 1 or 2, wherein prior to the step of adjusting the pH of the aqueous feed solution, the method comprises: providing a feed mixture comprising at least one metal selected from nickel, cobalt, and manganese, the feed mixture being one of an oxidizing feed, a reducing feed, or an unoxidized feed, wherein: The oxidizing feed has at least one metal with an oxidation state greater than 2 more than an oxidation state less than 2; the reducing feed has at least one metal with an oxidation state less than 2 more than an oxidation state greater than 2, or has at least one metal substantially entirely in an oxidation state of 2 and at least some of the at least one metal in sulfide form; and the unoxidizing feed has at least one metal substantially entirely in an oxidation state of 2 and substantially no at least one metal in its sulfide form; the feed mixture is treated with an aqueous solution to form a leachate containing the at least one metal, wherein the pH of the aqueous solution is such that the pH of the leachate is between about 1 and about 6, and wherein: if the feed mixture is an oxidizing feed, the treatment further includes adding a reagent containing a reducing agent; and if the feed mixture is a reducing feed, the treatment further includes adding a reagent containing an oxidizing agent; wherein the leachate contains at least one of nickel, cobalt, and manganese in an oxidation state of 2, and wherein the leachate is used to provide the aqueous feed solution.

9. The method of claim 1 or 2, wherein the supernatant contains more than 1000 mg / L of nickel, cobalt or manganese.

10. The method of claim 1 or 2, wherein prior to the step of adjusting the pH of the aqueous feed solution, the method comprises separating solid impurities from the aqueous feed solution using at least one separation technique selected from the group consisting of: decantation, centrifugation, filtration, agglomeration and sedimentation, or combinations thereof.

11. The method of claim 1 or 2, wherein prior to the step of adjusting the pH of the aqueous feed solution, the method comprises removing dissolved impurities from the aqueous feed solution using at least one separation technique selected from the group consisting of ion exchange, precipitation, adsorption and absorption, or a combination thereof.

12. The method of claim 1 or 2, wherein prior to the step of adjusting the pH of the aqueous feed solution, the method further comprises adding one or more of cobalt, manganese and nickel to the aqueous feed solution to adjust the ratio of nickel, cobalt and manganese to provide the desired molar ratio in the coprecipitate.

13. The method of claim 12, wherein the required molar ratio is 1:1:1 nickel:cobalt:manganese, 1:1:1 nickel:cobalt:manganese, 6:2:2 nickel:cobalt:manganese, 2:1:1 nickel:cobalt:manganese, 3:1:1 nickel:cobalt:manganese, 4:1:1 nickel:cobalt:manganese, 5:1:1 nickel:cobalt:manganese, 6:1:1 nickel:cobalt:manganese, 7:1:1 nickel:cobalt:manganese, 8:1:1 nickel:cobalt:manganese, 9:1:1 nickel:cobalt:manganese, 10:1:1 nickel:cobalt:manganese, 5:3:2 nickel:cobalt:manganese, 9:0.5:0.5 nickel:cobalt:manganese, or 83:5:12 nickel:cobalt:manganese.

14. The method of claim 1 or 2, wherein the step of separating the coprecipitate from the supernatant comprises decantation and / or filtration to separate the coprecipitate.

15. The method of claim 1 or 2, further comprising mixing the coprecipitate with lithium to provide a mixture.

16. The method of claim 15, further comprising the step of calcining the mixture.

17. The method of claim 16, wherein the mixture provides a battery pack performance of greater than 10 mAh / g after calcination.

18. The method of claim 1 or 2, wherein the coprecipitate comprises: (a) less than 10,000 ppm of alkaline earth metals on a dry solids basis; or (b) less than 10,000 ppm of metals and metalloid impurities on a dry solids basis.

19. The method of claim 1 or 2, wherein the method further comprises removing residual nickel and / or cobalt and / or manganese in the supernatant by precipitation and / or ion exchange.

20. A coprecipitate comprising at least two metals selected from nickel, cobalt and manganese, produced by any one of claims 1 to 19.

21. Use of the coprecipitate as claimed in claim 20 for the production of lithium-ion battery packs.

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