Metal Precipitation

Abstract

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

Description

[Technical field]

[0001] In one embodiment, the present invention relates to a method for producing a coprecipitate containing nickel, manganese and / or cobalt, and the coprecipitate produced thereby. In another embodiment, the present invention relates to a method for dissolving metals from a mixture for subsequent use in producing a coprecipitate.

[0002] (cross reference) This application claims priority to Australian Provisional Patent Application No. 2021900570, filed March 2, 2021, and Australian Provisional Patent Application No. 2021900571, filed March 2, 2021, the contents of which are incorporated herein by reference in their entireties. [Background technology]

[0003] Where a prior art document is referenced in this specification, it will be clearly understood that this reference is not an admission that the document forms part of the general knowledge in the art in Australia or any other country.

[0004] Lithium-ion cells (or batteries) make up a significant percentage of all portable batteries, and more generally, batteries, in the world. Their high energy density, long life, and light weight make them popular in a variety of applications, including electric vehicles, electric bicycles and other electric powertrains, and power tools. Among the most common active material combinations in such batteries are: D Kuckel- Ma Ngan- KoThe most important element in lithium-ion batteries is nickel, also known as NMC (or NCM) material. Different ratios of nickel, manganese and cobalt are used in the various types of lithium-ion batteries. The batteries can also use only one of these elements, or a combination of any two of these three elements, or one, two or three of these elements with one or more additional elements such as aluminum and magnesium. Different ratios of all these elements are used in the various types of lithium-ion batteries.

[0005] NMC materials for batteries are typically made by taking high purity individual salts of nickel, cobalt and manganese separately and dissolving them all in a solution in a specific ratio and purity. The solution is then subjected to a precipitation process to co-precipitate the three metals as hydroxides, carbonates or hydroxycarbonates. This is widely considered to be the only way to achieve the high purity precursor product composition required for acceptable electrochemical performance. However, a disadvantage of this method is that impurity elements must be removed from the nickel, cobalt and manganese feedstock in order for them to be used in the manufacture of battery materials. For example, NMC materials may require purities on the order of 150,000 moles of NMC for every mole of impurity element. An exemplary nickel sulfate used in batteries has 5 ppm or less of impurities such as copper, iron, cadmium, zinc and lead. Thus, multiple separation and purification steps are required to produce pure salts of nickel, cobalt and manganese, making them time and material (and therefore cost) intensive.

[0006] Nickel deposits typically have natural nickel:cobalt ratios in the range of 10:1 to 100:1, and therefore the relative ratios of nickel, cobalt and manganese in such deposits generally require modification prior to producing NMC materials. Nickel deposits also typically contain a variety of other minerals, including, for example, iron, magnesium and silicate minerals, and therefore will require significant processing before they can be used to produce NMC materials.

[0007] Another potential source of nickel, cobalt and manganese is from used lithium-ion batteries. As the market for lithium-ion batteries expands, the disposal of lithium-ion batteries is becoming an increasing concern from an economic and environmental standpoint. Environmentally, used batteries contain high concentrations of metals such as nickel, cobalt and manganese, as well as volatile fluorine-containing electrolytes. With the increasing demand for lithium-ion batteries and the drive to promote material recycling, there is an ever-increasing need to find better ways to recover NMC materials from the cathode active material (CAM or black mass) of used lithium-ion batteries in sufficient purity to allow them to be recycled into new lithium-ion batteries.

[0008] Lithium-ion batteries typically have five main components: the casing, electrolyte, separator, anode, and cathode. The casing is typically a steel shell that contains all other components and has little economic value. The electrolyte is used to carry charge through the battery and is made of a lithium-containing salt (typically lithium hexafluorophosphate or lithium tetrafluoroborate) dissolved in an aprotic organic solvent. The separator is typically a polymer membrane that separates the anode and cathode half-cells of the battery. Lithium-ion batteries typically have an anode made of graphite, which is connected to a copper current collector. Most of the battery's value comes from the cathode. Modern lithium-ion batteries have a cathode coated with an electrochemically active lithium compound containing cobalt oxide or a mixture of nickel, cobalt, and manganese (NMC). This cathode material is typically mixed with graphite and adhered to an aluminum current collector with a binder.

[0009] Various conditions have been attempted to recover NMC materials from the cathode active material, but it is difficult to recover nickel, cobalt and manganese without recovering significant amounts of undesirable impurities. Most attempts to recycle NMC materials to date have had the goal of producing individual salts of nickel, cobalt and manganese for further use, or producing highly purified solutions for further use.

[0010] Also, some battery applications may require the use of materials that contain only two of, for example, nickel, cobalt, and manganese, and the above considerations would also apply to such materials. Summary of the Invention [Means for solving the problem]

[0011] (Summary of the invention) In one embodiment, the present invention seeks to provide a method for producing a co-precipitate comprising at least two of nickel, manganese and cobalt, which may at least partially overcome or substantially ameliorate at least one of the above disadvantages or provide a useful or commercial option to consumers. The co-precipitate may be suitable for the preparation of a lithium-ion battery. In another embodiment, the present invention seeks to provide a precursor for use in the preparation of a lithium-ion battery, such as a precipitate of one or two or all three of nickel, manganese and cobalt, which may be suitable for subsequent use in the preparation of an NMC material, particularly a cathode active NMC material, or a material comprising at least two of nickel, manganese and cobalt, particularly a cathode active material. In another embodiment, the present invention seeks to provide a method for producing a solution which may be suitable (potentially after further processing) for use in producing a coprecipitate comprising nickel, manganese and cobalt, or which may at least partially overcome or substantially ameliorate at least one of the above disadvantages, or which may provide a useful or commercial option for consumers.

[0012] According to a first aspect of the present invention, there is provided a method for producing a coprecipitate comprising at least two metals selected from nickel, cobalt and manganese, said method comprising: (i) providing an aqueous feed solution containing said at least two metals; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, to co-precipitate said at least two metals from the feed solution.

[0013] The following options and embodiments may be used individually or in any suitable combination in conjunction with the first aspect.

[0014] The aqueous feed may comprise at least one impurity. Thus, adjusting the pH of the feed solution may provide a supernatant comprising said at least one impurity. Thus, in one embodiment of the first aspect, there is provided a method of producing a co-precipitate, wherein the co-precipitate comprises at least two metals selected from nickel, cobalt and manganese, the method comprising: (i) providing an aqueous feed solution containing said at least two metals and at least one impurity; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, to provide (a) a coprecipitate comprising said at least two metals; and (b) a supernatant comprising said at least one impurity.

[0015] In one embodiment, the method is a method for producing a coprecipitate, the coprecipitate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising: (i) providing an aqueous feed solution comprising the at least two metals and at least one impurity, the at least one impurity being 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) adjusting the pH of the aqueous feed solution to about 6.2 or greater but less than 10; (a) providing a coprecipitate comprising said at least two metals; and (b) providing a supernatant comprising said at least one impurity.

[0016] In one embodiment, the pH of the feed solution is adjusted to about 6.2-11, or about 6.2-less than 11, or about 6.2-10, or about 6.2-less than 10, or about 6.2-9.2, or about 6.2-8.5, or about 6.2-7.5.

[0017] In one embodiment, the total amount of the at least two metals (or the total amount of nickel, cobalt and manganese) in the aqueous solution is less than 95%, in particular 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% of the total weight of the aqueous solution (in particular the dry solids in the aqueous solution). In one embodiment, the total amount of metal complexes comprising at least two metals (or the total amount of metal complexes comprising nickel, cobalt and manganese) in the aqueous solution is less than 95%, in particular 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% of the total weight of the dry solids in the aqueous solution. The term "metal complex" as used herein includes, for example, sulfates of nickel, cobalt and 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 is 1 ppb or more of the aqueous solution, in particular 1 ppm or more, or 10 ppm or more, or 100 ppm or more, or 1,000 ppm or more, or 2,000 ppm or more, or 5,000 ppm or more, or 10,000 ppm or more, or 20,000 ppm or more, or 50,000 ppm or more.

[0018] As used herein, reference to "metal" or to a particular metal (e.g., nickel, cobalt, or manganese) does not necessarily mean that they are in metallic (i.e., oxidation state 0) form. Such references include the metal in all possible oxidation states, including salts of the metal, unless the context indicates otherwise.

[0019] As used herein, "at least one impurity" (which may be "at least one precipitated impurity") includes nickel, cobalt, manganese, water, OH, and the like. - , H + , H3O +, sulfate or carbonate. However, in one embodiment, the at least one impurity is not a nickel, cobalt or manganese complex with an anion (such as sulfate, carbonate, 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, 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, and zirconium, silver, tungsten, vanadium, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, lead, niobium, or combinations thereof; in particular, 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, or combinations thereof.In one embodiment, the at least one impurity includes or is: (i) calcium and / or magnesium; (ii) an alkaline earth metal; (iii) a metal or metalloid species (not including alkali metals); (iv) a metal or metalloid species not including alkali metals or anionic species (such as sulfate, sulfite, chloride, fluoride, nitrate, phosphate); or (v) a metal or metalloid species not including anionic species (such as sulfate, sulfite, chloride, fluoride, nitrate, phosphate).

[0020] In one embodiment, the at least one impurity is at least two impurities, or at least three impurities, or at least four impurities, or at least five impurities, or at least six impurities. Such impurities may be referred to herein.

[0021] In one embodiment, at least 1% of the at least one impurity in the aqueous feed solution of step (i) or step (ii), or at least 5% of the at least one impurity, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, in particular 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 present in the supernatant after co-precipitation, or in the washing solution after washing the coprecipitate, or in a combination of both the supernatant and the washing solution. The at least one impurity may be a combination of impurities. The amount of each impurity in the aqueous feed solution that may pass to the supernatant may be different for each impurity.

[0022] In one embodiment, the molar ratio (or mass ratio) of the at least two metals to the at least one impurity in the aqueous feed solution (or the molar ratio (or mass ratio) of the at least two metals to the 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 10,000,000:1, or less than 1,000,000:1, or less than 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 molar ratio (or mass ratio) of the at least two metals to the at least one impurity in the aqueous feed solution (or the molar ratio (or mass ratio) of the at least two metals to the total impurities in the aqueous feed solution) can be at least about 2,000,000:1, or at least about 1,000,000:at least about 100,000:1, 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. It refers to the sum of the molar (or mass) amounts of at least two metals, but can also refer to any one of at least one impurity, and may refer to the sum of the molar (or mass) amounts of all such impurities. At least one, optionally more than one, and in some cases all of the 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.

[0023] It should be understood that a reference to a metal herein does not imply that the metal is in the 0 oxidation state unless the context so indicates. For example, a reference to nickel may refer to any or all of Ni(0), Ni(II) and Ni(III), depending on the context. In one embodiment, the at least two metals selected from nickel, cobalt and manganese are all of nickel, cobalt and manganese. The nickel, cobalt and manganese may be in the appropriate oxidation state. In one embodiment, the at least two metals are selected from Ni(II), Co(II) and Mn(II).

[0024] In some embodiments, the feed solution in step (i) can have a pH of 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 feed solution in step (i) can have a pH of 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 certain embodiments, the feed solution of step (i) may have a pH of 1.0-4.0, 2.0-4.0, 4.0-6.0, 2.0-3.0, 3.0-4.0, 4.0-5.0, or 5.0-6.0, or 6.0-7.0. In some embodiments, the feed solution of step (i) may have a pH of 1.0-1.5, 1.5-2.0, 2.0-2.5, 2.5-3.0, 3.0-3.5, 3.5-4.0, 4.0-4.5, 4.5-5.0, 5.0-5.5, or 5.5-6.0, or 6.0-6.5, or 6.5-7.0. The pH of the feed solution of step (i) may be about 2.5-3.5. It may be about 3.0.

[0025] The aqueous feed solution may be a leachate comprising at least two metals selected from nickel, cobalt and manganese. Step (i) comprises producing a feed solution, which comprises producing a leachate by the methods herein. In an embodiment, the feed solution may be a leachate or the leachate may be used to provide the aqueous feed solution. In this embodiment, the term "using to provide an aqueous feed solution" may mean that the leachate is used directly as the aqueous feed solution or that the leachate is further processed or treated, and then the processed or treated solution is the aqueous feed solution of step (i).

[0026] Thus, in one embodiment of the present invention, prior to step (i), the method comprises the steps of: A. providing a feed mixture comprising at least one metal selected from nickel, cobalt and manganese, said feed mixture being one of an oxidized feed, a reduced feed or an unoxidized feed; the oxidation feed has more of the at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2; the reduced feed has more of the at least one metal in an oxidation state less than 2 than in an oxidation state greater than 2, or has substantially all of the at least one metal in an oxidation state of 2 and at least a portion (or at least some) of the at least one metal in sulfide form; and The unoxidized feed has substantially all of at least one metal in oxidation state 2 and substantially none of at least one metal in sulfide form; B. treating the feed mixture with an aqueous solution to form a leachate comprising the at least one metal, the aqueous solution having a pH such that the leachate has a pH of about -1 to about 7 (or about -1 to about 6, or about 1 to about 7, or about 1 to about 6); If the feed mixture is an oxidation feed, the treatment additionally includes the addition of a reagent comprising a reducing agent; and If the feed mixture is a reduced feed, the treatment additionally includes the addition of a reagent comprising an oxidizing agent; This results in a leachate containing at least one metal in oxidation state 2, (or step (i) may comprise the steps described above).

[0027] In this embodiment, the phrase "having more" (e.g., the phrase "the oxidation feed has more of at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2") should be interpreted as "having a greater molar concentration." The term "substantially all of" can refer to at least 90%, or at least 95%, or at least 99%, or at least 99.5%, or at least 99%, each on a molar basis. The various options and embodiments described below may be used individually or in any suitable combination.

[0028] In one embodiment, the at least one metal can be at least two metals.

[0029] In one embodiment, step (i) comprises: providing a feed mixture comprising at least two metals, said feed mixture being one of an oxidized feed, a reduced feed or an unoxidized feed; the oxidation feed has more of the at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2; the reduced feed has more of the at least two metals in an oxidation state less than 2 than in an oxidation state greater than 2, or has substantially all of the at least two metals in an oxidation state of 2 and at least a portion of the at least two metals in sulfide form; and the unoxidized feed has substantially all of the at least two metals in oxidation state 2 and substantially none of the at least two metals in sulfide form; treating the feed mixture with an aqueous solution to form a leachate comprising the at least two metals, the aqueous solution having a pH such that the leachate has a pH of about -1 to about 6 (or about 1 to about 6); If the feed mixture is an oxidation feed, the treatment additionally includes the addition of a reagent comprising a reducing agent; and If the feed mixture is a reduced feed, the treatment additionally includes the addition of a reagent comprising an oxidizing agent; This results in a leachate containing at least one metal in oxidation state 2, providing the aqueous feed solution, the aqueous feed solution being a leachate; Includes.

[0030] Examples of oxidizing feeds as defined above may include a mixture of Ni(II), Co(III) and Mn(0) 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 Ni(II) and Mn(III) without Co. Examples of reducing feeds as defined above may include a mixture of Ni(II), Co(II) and Mn(II)S in any ratio, or a mixture of Ni(0), 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 also refer to oxidation state of 2 or +2, which are used interchangeably. In one embodiment, the leachate includes Co(II), Mn(II) and Ni(II).

[0031] In one embodiment, nickel, cobalt and / or manganese laterite ores are typically considered to be oxidized feeds. In another embodiment, mixed hydroxide precipitates, mixed carbonate precipitates, or oxides or carbonates of nickel, cobalt and / or manganese are typically considered to be oxidized or unoxidized feeds. In one embodiment, nickel and / or cobalt sulfide ores or concentrates are typically considered to be reduced feeds. In another embodiment, mixed sulfide precipitates are typically considered to be reduced feeds. In another embodiment, ferronickel, nickel pig iron, nickel, cobalt and / or manganese metal alloys are typically considered to be reduced feeds. In a further embodiment, recycled materials from lithium ion batteries are typically considered to be oxidized feeds.

[0032] In one embodiment, the mixture includes nickel, cobalt and manganese, whereby the aqueous solution includes nickel, cobalt and manganese, in another embodiment, one of these metals is absent from the mixture, whereby the aqueous solution includes two of nickel, cobalt and manganese but none of the others.

[0033] In one embodiment, the feed mixture is an oxidized feed and the reagent comprises a reducing agent. In another embodiment, the feed mixture is a reduced feed and the reagent comprises an oxidizing agent. In a further embodiment, the feed mixture is an unoxidized feed and neither a reducing agent nor an oxidizing agent is used.

[0034] Previously published processes have used a 4M sulfuric acid solution in the leaching step, which is a very strong acid with a pH below 0. This is a very corrosive acid and will lead to significant dissolution of impurity elements, including iron, aluminum, and copper. If elements such as iron and aluminum are dissolved, this will consume more acid in the leaching step, and their separation and / or removal in the precipitation or other impurity separation and / or removal steps will consume more base or other reagents.

[0035] In contrast, the leaching step described above involves treating the mixture in an aqueous solution having a pH of about 1 to about 7 or about 1 to about 6 (a pH 1 solution of sulfuric acid corresponds to about 0.05M sulfuric acid). This small acidic pH dissolution of iron, aluminum, and to a lesser extent copper is less favorable. Conversely, nickel, cobalt, and manganese all dissolve at a pH below about 6 when in an oxidation state of +2. The use of this step provides a surprisingly effective and cost effective method for preparing a solution suitable for co-precipitating at least two of Ni, Mn, and Co with improved purity when compared to prior art approaches utilizing more acidic conditions. It should be noted that one skilled in the art can readily determine by routine experimentation and / or theory the amount and concentration of a particular acid required to achieve a target pH.

[0036] The mixture may be a solid mixture. It may be a mixture in which at least a portion of the nickel, manganese, and cobalt are in solid form (e.g., in a slurry). In one embodiment, the mixture is a mixed hydroxide precipitate (or "MHP"). MHPs are solid nickel-cobalt mixed hydroxide precipitates that are known intermediate products in the commercial processing of nickel-containing ores. MHPs may be derived from nickel sulfide ore or lateritic nickel ore. Such MHPs may provide an oxidation feed, since at least a portion of the manganese and cobalt contained in the MHP may be in an oxidized form. MHPs may be derived from a crude recycling process or from any nickel- and cobalt-containing aqueous solution.

[0037] In one embodiment, the mixture is a product (typically a solid residue) obtained from a selective acid leaching (SAL) process as disclosed in PCT / AU2012 / 000058, in which the pH and amount of oxidizing agent are controlled to selectively dissolve at least a portion of the nickel in solution. In this process, the amount of oxidizing agent is typically to oxidize at least a portion of the cobalt and / or manganese to Co(III). Thus, use of this process would typically provide an oxidized raw material (or feed). In the SAL process, MHP is used as described above.

[0038] Thus, in one embodiment, prior to treatment, the method comprises the steps of: (a) contacting an MHP containing at least two metals with an acidic solution (which may contain an oxidizing agent) at a pH that stabilizes one of the metals (particularly cobalt) in the solid phase and dissolves another of the metals in the acidic solution; and (b) separating a solid phase from the acidic solution, the solid phase comprising said at least two metals, the solid phase forming at least a portion of the feed mixture.

[0039] In a specific 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 pH that stabilizes the cobalt in the solid phase and dissolves the nickel in the acidic solution; and (b) separating a solid phase from the acidic solution, the solid phase comprising at least two metals, one of which is cobalt, and the solid phase forming at least a portion of the feed mixture. In this embodiment, the solid phase comprising the at least two metals may be a feed mixture.

[0040] In one embodiment, prior to step (a), the MHP is washed. The MHP may be treated with an oxidizing agent in the washing step.

[0041] In one embodiment, the feed mixture comprises cobalt and nickel, and step A comprises: (a) contacting a mixed hydroxide precipitate and / or a mixed carbonate precipitate comprising at least cobalt and nickel with an acidic solution containing an oxidizing agent at a pH that stabilizes the cobalt in the solid phase and dissolves the nickel in the acidic solution; and (b) separating a solid phase from the acidic solution, the solid phase comprising at least two metals, one of which is cobalt, and the solid phase forming at least a portion of the feed mixture.

[0042] In one embodiment, cobalt is stabilized in the solid phase in the form of Co(III). In one embodiment, manganese is stabilized in the solid phase in step (a) in the form of Mn(III).

[0043] The pH of the acidic solution, or aqueous solution, or leachate in step (a) can be about 1 to about 6, or 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 in step (a) can be the end point (or final) pH at the end of step (a). The pH in step (a) can be the pH throughout step (a).

[0044] The oxidizing agent 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 or potassium persulfate, sodium or potassium permanganate, ozone, magnesium or hydrogen peroxide, chlorine gas or sodium or potassium perchlorate. It may be a persulfate or a permanganate. It may be sodium or potassium persulfate, sodium or potassium peroxyhydrogen disulfate, sodium or potassium permanganate.

[0045] In one embodiment of step (a), an oxidizing agent is added in a stoichiometric equivalent amount of about 70% to about 500% relative to the total moles of metals to be stabilized in the solid phase, e.g., cobalt and manganese; e.g., about 80% to about 400%; about 80% to about 200%, or 100% to about 150%, e.g., the stoichiometric equivalent amount is about 70, 80, 90, 100, 110, 120, 125, 130, 140, 150, 200, 250, 300, 350, 400, 450, or 500%.

[0046] The temperature in step (a) can be greater than about 20° C. and less than about 120° C., or greater than about 50° C. and less than about 100° C., or from about 60° C. to about 90° C. The temperature can be about 25° C., 30° C., 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 95° C., 100° C., 105° C., 110° C., or 115° C.

[0047] In step (b), the separation step can be a filtration step.

[0048] In one embodiment, the method may include removing impurities from a feed mixture comprising at least two metals selected from nickel, cobalt and manganese prior to said treating. The method may include contacting the mixture (or precursor) comprising said at least one metal (or at least two metals) with a weak acid leach solution (which may be for providing at least a portion of the mixed feed). The weak acid leach solution may have a concentration of about 0.005M to about 0.5M acid, or about 0.01M to 0.3M, about 0.01M to 0.1M, about 0.02M to 0.08M, about 0.03M to 0.07M, about 0.04M to 0.06M, or about 0.05M to 0.1M acid, e.g., about 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4 or 0.5M acid. The acid in the weak acid leach solution may be an inorganic acid or an organic acid. The inorganic acid may be selected from the group consisting of sulfuric acid, hydrochloric acid and nitric acid. The organic acid may be selected from acetic acid or formic acid. Other acids are also suitable. The acid in the weak acid leach may be sulfuric acid.

[0049] Step (a) may be carried out at any suitable pressure, typically atmospheric pressure. Step (a) may provide a slurry. The slurry may have about 1% solids to about 40% solids by weight, or about 5% solids to about 40% solids by weight, or about 10% solids to about 30% solids by weight, e.g., about 1, 5, 10, 15, 20, 25, 30, 35, or 40% solids by weight.

[0050] After step (a), the solids may be separated from the liquid, for example, by filtration. The solids may be used as a feed mixture for step (b). Step (a) is useful for removing and / or separating impurities selected from the group consisting of one or more of calcium, magnesium and zinc. Additionally or alternatively, other impurities may be removed and / or separated.

[0051] In another embodiment, the feed mixture is a product derived from or obtained from a lithium ion battery, particularly a cathode material of a lithium ion battery. It can be from recycled NMC materials. The product can have a total amount of nickel, cobalt and manganese greater than about 1% by weight, or greater than about 2, 3, 4, 5, 10, 20, 30, 40, 50, 60% by weight on a dry basis. The product can include greater than about 0.1% by weight, or greater than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 10, 20, 30 or 35% by weight of nickel on a dry basis. It can include greater than about 0.1% by weight, or greater than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5 or 10% by weight of cobalt on a dry basis. The product may contain greater than about 0.1%, or greater than about 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 10 or 15% manganese by weight on a dry basis.

[0052] Thus, in another embodiment, prior to said processing, the method may include the step of separating the cathode material from a discharged lithium ion battery. The separating step may include shredding or crushing the battery. The separating step may include removing the casing of the lithium ion battery. The separating step may include separating the casing, electrolyte, anode and cathode. The separated cathode material may form the mixture to be processed, and the mixture to be processed may originate from the cathode material separated in the method of the first aspect.

[0053] When the cathode material is made, it is calcined and the nickel, cobalt and manganese are oxidized. Thus, once the cathode is used and recycled, the spent cathode material has a very similar chemical state to the SAL process residue. Thus, the spent cathode material may be used in the method of the first aspect of the present invention.

[0054] In one embodiment, the mixture being treated can be a product (particularly a solid residue) obtained from the selective acid leaching (SAL) process disclosed in PCT / AU2012 / 000058 (supra); a product from recycled lithium ion batteries; a product from recycled NMC materials; or a combination thereof.

[0055] In one embodiment, the feed is a mixture. In another embodiment, the feed is a filter cake, e.g., a wet filter cake. In another embodiment, the feed is a slurry. The slurry can have about 1% to about 40% by weight solids, or about 5% to about 40% by weight solids, or about 10% to about 30% by weight solids, e.g., about 5, 10, 15, 20, 25, 30, 35, or 40% by weight solids.

[0056] In the above embodiment of the method 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 oxidation state, i.e., an oxidation state greater than 2. As mentioned above, the majority of nickel, manganese and cobalt contained in the solid residue obtained from the SAL process may be in an oxidation state. Due to the poor solubility associated with these oxidized metal components, the solubility of these metals in an aqueous solution having a pH of about 1 to about 6 can be significantly improved through treatment with a reducing agent. Thereby, the cobalt, manganese and nickel reduced to oxidation state 2 can be selectively dissolved in the aqueous solution with respect to one or more impurities (or leaching impurities) in the aqueous solution.

[0057] In one embodiment, at least about 5%, 10%, 20%, 30%, 40%, 50% or 60% of the at least one metal (or at least two metals) selected from cobalt, manganese and nickel in the feed mixture being treated is in an oxidized state.

[0058] The oxidized forms of cobalt may include Co(III) and / or Co(IV); in particular Co(III). The oxidized forms of manganese may include one or more of Mn(III), Mn(IV), Mn(V); typically Mn(III). The oxidized forms of nickel may include Ni(III) and / or Ni(IV), typically Ni(III). The mixture may also include substantial amounts of cobalt, manganese and / or nickel in the desired (II) state.

[0059] However, the solubility (or dissolution) profiles of some of the major leaching impurities in the solid residue, particularly iron (Fe), aluminum (Al), and to a lesser extent copper (Cu), overlap to some extent with the solubility profiles of the desired nickel, manganese, and cobalt components. For example, the desired +2 oxidation state forms of nickel, manganese, cobalt, and iron (Fe(II)) are all relatively soluble at a pH of about 3 to about 7, but the oxidized forms of these metals only become significantly soluble in aqueous solutions below about pH 3. In the case of aluminum and copper, although none of these leaching impurities exhibit the same oxidation / reduction behavior as nickel, manganese, and cobalt, they are quite soluble in aqueous solutions below about pH 3 and about 4, respectively.

[0060] In one embodiment, the feed mixture may include one or more leaching impurities 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.

[0061] It will be appreciated that in most cases the type and amount of these leached impurities will depend greatly on the extent of processing the solid residue was subjected to prior to carrying out the method and what materials were used as starting materials. For example, if the solid residue was obtained directly from a SAL process, it is likely to contain significantly more iron (Fe) and aluminum (Al) than if it was obtained directly from the cathode active material (CAM) itself, especially if the CAM was first partially processed via a recycling process.

[0062] In one embodiment, the aqueous solution used in the treatment includes a leaching agent. The leaching agent can be an acid. The acid can be used to provide a pH of about 1 to about 7, or about 1 to about 6. The leaching agent can be an inorganic acid or an organic acid. The inorganic acid can be selected from the group consisting of sulfuric acid, hydrochloric acid, and nitric acid. The organic acid can be selected from acetic acid or formic acid. Other acids are also suitable. The leaching agent can be sulfuric acid.

[0063] The pH of the aqueous solution may 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 aqueous solution may be (or such that the leachate has) a pH 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 certain embodiments, the aqueous solution may have (or the infusion solution may have) a pH of 1.0-4.0, 2.0-4.0, 4.0-6.0, 2.0-3.0, 3.0-4.0, 4.0-5.0, or 5.0-6.0, or 6.0-7.0. In some embodiments, the aqueous solution may have a pH of 1.0-1.5, 1.5-2.0, 2.0-2.5, 2.5-3.0, 3.0-3.5, 3.5-4.0, 4.0-4.5, 4.5-5.0, 5.0-5.5, or 5.5-6.0, or 6.0-6.5, or 6.5-7.0. The pH of the aqueous solution may be about 2.5-3.5. It may be about 3.0. The inventors have found that more leach impurities dissolve in the aqueous solution if the pH is below 1. However, the ability of the aqueous solution to dissolve the desired +2 oxidation state forms of nickel, cobalt and manganese is reduced if the pH is above 6 or 7. The pH of step B may be the end pH of the solution at the end of that step, i.e., the pH of the leachate at the end of step B.

[0064] In one embodiment, the method may include the step of adding a leaching agent to the aqueous solution. In another embodiment, the method may include the step of controlling the pH of the aqueous solution. In one embodiment, the pH of the aqueous solution may be controlled through the addition of an acidic leaching agent, as defined above. In another embodiment, the pH of the aqueous solution may be controlled through the addition of a base. Examples of bases may include alkali or alkaline earth hydroxides, such as sodium hydroxide. However, the base may be a nickel, cobalt or manganese containing material, such as a fresh solid (from the mixture to be treated, or from a precipitate of nickel, cobalt and manganese, such as a hydroxide precipitate), or a hydroxide compound, or a carbonate compound, or a hydroxyl carbonate compound. The advantage of using a nickel, cobalt or manganese containing material, particularly a nickel, cobalt or manganese containing material that contains at least an oxidized portion, is that the addition of this material also consumes the reducing agent remaining in the solution, and the Fe 2+ Fe 3+ Change the conditions to oxidize to Fe 3+ is more favorably precipitated than Ni or Co.

[0065] In one embodiment, the leaching agent is added to the aqueous solution (or "leach solution") at a controlled rate. In one embodiment, the leaching agent can be added in stages until the solution reaches the desired end pH (the desired end pH can be as described for the pH of the aqueous solution above). In another embodiment, all of the leaching agent can be added to the aqueous solution in one step. In another embodiment, the leaching agent can be added gradually over the course of the process (i.e., over a period of time as 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 is combined with the feed mixture.

[0066] The lixiviant may be added to the aqueous solution at a rate of about 10,000 to about 20,000 moles of lixiviant per ton of nickel, cobalt and manganese mixture; for example, about 12,000 to about 17,000 moles of lixiviant per ton of nickel, cobalt and manganese mixture; or 14,000 to 14,500 moles of lixiviant per ton of nickel, cobalt and manganese mixture. The sulfuric acid may be added to the aqueous solution at a rate of about 1.0 to about 2.0 tons of H2SO4 or at a rate of about 1.2 to about 1.7 tons of H2SO4 per ton of nickel, cobalt and manganese mixture; or at a rate of about 1.4 tons of H2SO4 per ton of nickel, cobalt and manganese mixture.

[0067] The reducing agent may be selected from the group consisting of hydrogen gas, SO2 gas, sulfites (such as sodium metabisulfite), organic acids, sulfides (such as nickel, sodium, potassium, cobalt, or manganese sulfides, or sodium, potassium, cobalt, or manganese hydrosulfides), and hydrogen peroxide, or combinations thereof. The reducing agent may be SO2 gas, sodium metabisulfite, or combinations thereof. The reducing agent may be SO2 gas. A combination of reducing agents may be used. In one embodiment, the reducing agent may be selected from the group consisting of hydrogen gas and SO2 gas. Advantageously, hydrogen gas and SO2 gas are both strong enough to reduce cobalt, manganese, and nickel, and do not introduce impurities into the leach solution. When selecting a suitable reducing agent, it is preferable to select an agent 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. Also, SO2 gas present in solution may generate acid in situ (e.g., via reaction with the solution or an oxidizing agent). In one embodiment, the reducing agent is a gas at atmospheric pressure and temperature. In another embodiment, the reducing agent is a liquid at atmospheric pressure and temperature. In a further embodiment, the reducing agent is a solid at atmospheric pressure and temperature.

[0068] The aqueous solution and, if used, the reagents can be added independently over a period of about 0.25 to about 5 hours, or about 0.25 to 1, 0.25 to 0.5, 0.5 to 1, 0.5 to 2 hours, 1 to 4 hours, 1 to 3 hours, 1 to 2 hours, 2 to 5 hours, 3 to 5 hours, or 3 to 4 hours, e.g., about 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5 3, 3.5, 4, 4.5, or 5 hours, and in some circumstances one or both of these can be added over a period of more than 5 hours. They can be added independently or together. They can be added simultaneously, sequentially, or alternately (if added batchwise or semi-continuously). Each can be added independently batchwise or continuously, and can be added semi-continuously (i.e., continuously but with periods of no addition). The reagents may be added in a stoichiometric ratio of about 70 to about 500%, or about 100 to 500%, 200 to 500%, 300 to 500%, 100 to 300%, 70 to 200%, 70 to 100% or 70 to 150%, for example, about 70, 80, 90, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450 or 500%, relative to the two or more metals to be oxidized or reduced, although ratios outside these ranges may be suitable in certain cases.

[0069] In one embodiment, the reducing agent is not hydrogen peroxide. Previously described processes using hydrogen peroxide can oxidize the iron present and reduce the nickel, cobalt and manganese in the recycled cathode material. In these processes, because bulk amounts of hydrogen peroxide are used (hydrogen peroxide is a relatively weak reducing agent for nickel, cobalt and manganese), there is little control over the reduction reaction. Furthermore, hydrogen peroxide is a relatively expensive reagent, requires the addition of additional acid, and hydrogen peroxide causes significant dilution with associated water.

[0070] The inventors have advantageously found that in order to selectively dissolve the oxidized forms of nickel, manganese and cobalt relative to the various leach impurities in the mixture, it is necessary to convert these oxidized forms of nickel, manganese and cobalt in the mixture to the desired +2 oxidation state forms which are then solubilized at a pH of from about 1 to about 6.

[0071] In one embodiment, the method may include the step of adding a reducing agent to the aqueous solution. In another embodiment, the method may include the step of controlling the addition of the reducing agent to the aqueous solution. The addition of the reducing agent to the aqueous solution may be controlled to substantially reduce the oxidized cobalt, manganese and / or nickel components to the desired +2 oxidation state while minimizing the reduction of a major leach impurity such as iron (Fe), which has a wider pH range of solubility in the reduced Fe(II) form. In one embodiment, the method of the first aspect may be carried out under conditions that preferentially reduce the cobalt, manganese and / or nickel oxides relative to the leach impurities in the mixture. Such leaching impurities may be at least one selected from 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; in particular, at least one selected from the group consisting of aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium (in particular, all of the group consisting of them).

[0072] The inventors have advantageously discovered that, in terms of the reduction reaction, the oxidized nickel should be reduced first, followed by the cobalt, manganese, and iron in that order. Thus, in one embodiment, the amount of reducing agent added to the mixture is selected to reduce the oxidized nickel, cobalt, and manganese, but not substantially oxidize the iron.

[0073] In one embodiment, about 0.5 to about 2 stoichiometric equivalents of reducing agent are added to the aqueous solution relative to the total moles of cobalt oxide, manganese oxide, and nickel oxide (some of these metal oxides may be absent); or about 0.7 to 1.5, 0.8 to 1.2, or 0.9 to 1.1 stoichiometric equivalents of reducing agent are added. About 1 stoichiometric equivalent may be added, 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 equivalent of reducing agent is typically sufficient to reduce one equivalent of nickel, manganese, or cobalt oxide. The reducing agent may be added to the aqueous solution at a rate of about 3,000 to about 10,000 moles of reducing agent per ton of feed mixture; or about 5,000 to 8,000 moles or about 6,000 to 6,500 moles of reducing agent per ton of feed mixture. SO2 may be added to the aqueous solution at a rate of about 0.2 to about 0.6 tons of SO2 per ton of feed mixture; or at a rate of 0.3 to 0.5 tons of SO2 per ton of feed mixture; for example, about 0.3, 0.4, or 0.5 tons of SO2 per ton of feed mixture.

[0074] In one embodiment, about 0.5 to about 5 stoichiometric equivalents of oxidizing agent are added to the aqueous solution relative to the total moles of reduced cobalt, reduced manganese, and reduced nickel (some of these reduced metals may be absent); or about 0.5 to 2, 0.7 to 1.5, 0.8 to 1.2, or 0.9 to 1.1 stoichiometric equivalents of oxidizing agent are added. About 1 stoichiometric equivalent may be added, and 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. In one embodiment of step B, about 70% to about 500% stoichiometric equivalent of oxidizing agent is added relative to the total moles of reduced cobalt, reduced manganese, and reduced nickel (some of these reduced metals may be absent); for example, about 80% to about 400%; 80% to 200%, or 100% to 150%, for example, about 70, 80, 90, 100, 110, 120, 125, 130, 140, 150, 200, 250, 300, 350, 400, 450, or 500% stoichiometric equivalent of oxidizing agent is added.

[0075] In one embodiment, the reagents (particularly the reducing agent) are added to the aqueous solution (or "leachate") at a controlled rate. The reagents (particularly the reducing agent) may be added continuously over a specific period of time. A suitable period of time may be from about 15 minutes to about 3 hours; or from about 30 minutes to about 2 hours; or from about 30 minutes to about 1 hour; or from about 1 hour to about 3 hours; or from about 1 hour to about 2 hours. The inventors have found that a slower rate of addition provides greater selectivity for leach impurities, but a faster rate of addition improves throughput.

[0076] In one embodiment, the treatment is carried out in a sealed vessel. Advantageously, the use of a sealed vessel reduces gas loss, allows greater control of the reduction or oxidation reaction (as appropriate), and allows for more gradual addition of the reducing or oxidizing agent (particularly 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. Carrying out the treatment at a slight overpressure is useful to suppress excess gas.

[0077] The inventors have found that for at least some reagents (such as some reducing agents), the addition of the reagent can affect the pH of the aqueous solution, and therefore, in some embodiments, it may be necessary to control the pH of the solution, for example, through the addition of acid or base.

[0078] In some embodiments when a reducing agent is used, control of the pH and reduction reaction allows for selective dissolution of nickel, cobalt and manganese while limiting the leaching of iron, aluminum and copper to about 40% by weight, or to about 30%, 20%, 15%, 12% by weight, respectively. Advantageously, with this process a significant portion of some of the leached impurities can remain in the solid phase.

[0079] In another embodiment, the process provides a leachate comprising dissolved nickel, cobalt, and manganese, and iron, aluminum, copper, barium, cadmium, calcium, carbon, chromium, lead, lithium, magnesium, potassium, phosphorus, sodium, silicon, fluorine, sulfur, titanium, zinc, and zirconium; or a solid comprising at least one of the group consisting of aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium (or all of the group consisting of them).

[0080] In one embodiment, step B is carried out at a temperature at which the aqueous solution maintains a liquid state. In one embodiment, step B is carried out at a temperature of about 0°C to 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 specifically, about 50°C to about 100°C; or about 60°C to about 100°C. In another embodiment, step B is carried out at a temperature of about 60°C to 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, the reaction is carried out at a temperature of about 0° C. to 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 may be carried out at about 0° C., 10° C., 20° C., 30° C., 40° C., 50° C., 60° C., 70° C., 80° C., 90° C. or 100° C., or about 55° C. The temperature of the aqueous solution may increase over time as the reaction / process is typically exothermic.

[0081] In one embodiment, step B may be carried out 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.

[0082] In one embodiment, step B may be carried out for a period of time. As outlined above, the time required for the treatment of the first aspect may be affected by factors such as the temperature at which the reaction is carried out, the pH of the solution, and the reagents. However, in one embodiment, the treatment may be carried out 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, the treatment may be carried out 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.

[0083] In one embodiment, the treatment is carried out with mixing or stirring, e.g., with stirring.

[0084] In one embodiment, the process may be performed using at least one vessel. The at least one vessel may be one vessel or may be two vessels. The vessel may be a mixing vessel and may be configured to mix liquids (or may contain entrained solids) therein. The vessel may be agitated. The vessel may include an agitator (or stir bar or stirrer).

[0085] The treatment may be carried out at any suitable ratio of liquid to solid. In one embodiment, the solid-liquid mixture may contain at least about 1% solids by weight (or 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 4-20%, 1-10%, 3-7% or 4-6% solids by weight. In one embodiment, the feed mixture and the aqueous solution together form a slurry.

[0086] 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 being treated). Also, a manganese salt, carbonate, or hydroxide salt (typically a carbonate or hydroxide salt) may be added at this step. A suitable manganese salt may be MnCO3. Suitable carbonates include MnCO3, Ni(OH)(CO3). 0.5 , NiCO3, CoCO3, Co(OH)2, Na2CO3 and CaCO3. Suitable hydroxide salts include Ni(OH)2, Ni(OH)(CO3) 0.5 , NaOH, and Ca(OH)2. This step may be carried out at any suitable temperature and is generally similar to that previously described for the treatment. This step may be carried out for any time period, such as, for example, from about 30 minutes to about 10 hours, or from about 3 hours to about 10 hours, or from about 4 hours to about 8 hours. This step may avoid the need to remove or separate impurities such as magnesium, sodium, calcium, zinc. This step may consume any reducing agent remaining in the solution.

[0087] In one embodiment, the method may include adding an oxidizing agent and / or reducing agent to neutralize 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, for example, to a pH above step B but below pH 7 (e.g., pH 6). The method may include filtering the solution before neutralizing the excess reducing agent and / or oxidizing agent, or increasing the pH.

[0088] After treatment, impurities (or "leach impurities") may be removed and / or separated from the leachate in any suitable manner. In this context, the term "impurities" or "leach impurities" or "leach impurities") refers to nickel, cobalt, manganese, water, OH, - , H + , H3O +The term "solid leaching impurities" refers to metals, complexes, compounds or elements that are not salts, sulfates or carbonates. A suitable technique for removing impurities may be selected by one skilled in the art based on the nature of the impurities. For example, at least a portion of the leaching impurities may be in solid form. In one embodiment, the solid leaching impurities may be removed and / or separated from the aqueous solution using at least one separation technique selected from the group consisting of decantation, filtration, cementation, centrifugation and sedimentation, or a combination of any two or more thereof. Exemplary solid leaching 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.

[0089] The leachate may include at least one liquid leach impurity. Exemplary liquid leach impurities in the leachate 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, scandium, iron, zinc and zirconium, silver, tungsten, vanadium, molybdenum, platinum, rubidium, tin, antimony, selenium, bismuth, boron, yttrium, lead, niobium, or combinations thereof; in particular, at least one leaching impurity selected from the group consisting of 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, niobium, or combinations thereof.

[0090] 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 metals or three metals):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 by weight.

[0091] In another example, at least a portion of the leaching impurities may be in liquid (or dissolved) form. In one embodiment, the liquid (or dissolved) leaching impurities may be removed and / or separated from the aqueous solution using at least one separation technique selected from the group consisting of ion exchange, precipitation, absorption / adsorption, electrochemical reduction and distillation, or a combination of any two or more thereof, typically ion exchange, precipitation and adsorption, or a combination thereof. In this context, the term "impurities" or "leaching impurities" refers to metals that are not cobalt, nickel, or manganese, but may include unwanted non-metals or metalloids. Exemplary liquid leaching impurities 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 a combination thereof.

[0092] In one embodiment, the concentration of alkali metal (such as Na, Li, K) (or at least one alkali metal) liquid leach impurity in the leachate is 100,000 ppm or less, or 80,000 ppm or less, or 60,000 ppm or less, or 50,000 ppm or less, or 40,000 ppm or less, or 30,000 ppm or less, or 20,000 ppm or less, or 15,000 ppm or less, or 10,000 ppm or less, or 7,000 ppm or less, or 5,000 ppm or less, or 4,000 ppm or less, or 3,000 ppm or less, or 2,500 ppm or less, or 2,000 ppm or less. In another embodiment, the molar ratio of the at least one metal (or at least two metals) in the leachate to the alkali metal liquid leach 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 the at least one metal (or at least two metals) to the alkali metal liquid leach impurity (or at least one alkali metal impurity) in the leachate can 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 the at least one metal (or at least two metals) to the alkali metal liquid leach impurity (or at least one alkali metal impurity) in the leachate can be from about 1:10 to 23,000:1, or from about 1:10 to 100,000:1, or from about 1:10 to 300,000:1.

[0093] In one embodiment, the anionic liquid leaching impurities (F -and Cl - and the like (but excluding oxides, hydroxides, sulfates, carbonates) (or at least one anionic liquid impurity) is not more than 100,000 ppm, or not more than 80,000 ppm, or not more than 60,000 ppm, or not more than 50,000 ppm, or not more than 40,000 ppm, or not more than 30,000 ppm, or not more than 20,000 ppm, or not more than 10,000 ppm, or not more than 5,000 ppm, or not more than 4,000 ppm, in particular not more than 3,000 ppm, or not more than 2,500 ppm, or not more than 2,000 ppm. In another embodiment, the molar ratio of the at least one metal (or at least two metals) to the anionic liquid leach impurity (or at least one anionic liquid impurity) in the leachate 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 the at least one metal (or at least two metals) to the anionic liquid leach impurity (or at least one anionic impurity) in the leachate can 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.

[0094] In another embodiment, the concentration of alkaline earth metal liquid leach 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 further embodiments, the molar ratio of the at least one metal (or at least two metals) in the leachate to the alkaline earth metal liquid leaching impurity (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 the at least one metal (or at least two metals) in the leachate to the alkaline earth metal liquid leaching impurity (or at least one alkaline earth metal liquid impurity) is from about 300,000,000: 1 to about 1:10; or greater than about 1:10, or greater than 1:1. In one embodiment, the molar ratio of the at least one metal (or at least two metals) in the leachate to the alkaline earth metal liquid leach 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.

[0095] In further embodiments, the concentration of metal and metalloid liquid leaching impurities (or at least one metal or metalloid impurity) in the leachate is less than 250 ppm, in particular less than 50 ppm. Exemplary metal 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) to metal and metalloid liquid leaching impurities (or at least one metal or metalloid liquid impurity) in the leachate 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 the at least one metal (or at least two metals) to Fe impurities in the leachate 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 the at least one metal (or at least two metals) to Fe impurities in the leachate 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 the at least one metal (or at least two metals) to Al impurities in the leachate 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 the at least one metal (or at least two metals) to Al impurity in the leachate is less than 10,000:1, or less than 20,000:1, or less than 100,000:1.

[0096] In one embodiment of the present invention, a method for producing a coprecipitate is provided, the coprecipitate comprising at least one metal selected from nickel, cobalt and manganese, the method comprising: (i) providing a feed mixture comprising at least one metal and at least one impurity, said feed mixture being one of an oxidized feed, a reduced feed or an unoxidized feed; the oxidation feed has more of at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2; the reduced feed has more of the at least one metal in an oxidation state less than 2 than in an oxidation state greater than 2, or has substantially all of the at least one metal in an oxidation state of 2 and at least a portion of the at least one metal in sulfide form; and The unoxidized feed has substantially all of at least one metal in oxidation state 2 and is substantially free of at least one metal in sulfide form; treating the feed mixture with an aqueous solution to form a leachate containing the at least one metal, the aqueous solution having a pH of about 1 to about 7; If the feed mixture is an oxidation feed, the treatment additionally includes the addition of a reagent comprising a reducing agent; and If the feed mixture is a reduced feed, the treatment additionally includes the addition of a reagent comprising an oxidizing agent; This results in a leachate containing at least one metal in oxidation state 2, providing an aqueous feed solution comprising the at least one metal, the aqueous feed solution being a leachate; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2 to provide (a) a precipitate comprising said at least one metal; and (b) a supernatant comprising said at least one impurity. Includes. In this embodiment, the method may further comprise the step of mixing at least one metal with the aqueous feed solution such that step (ii) provides a co-precipitate comprising at least two metals selected from nickel, cobalt and manganese (or comprising three metals).

[0097] In one embodiment, at least 1% of the at least one impurity in the feed solution of step (ii), or at least 5% of the at least one impurity, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, in particular 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 present in the supernatant after co-precipitation, or in the wash solution after washing the coprecipitate, or in a combination of both the supernatant and the wash solution. Also, the at least one impurity may be a plurality of impurities. The amount of each impurity in the aqueous feed solution that may be contained in the supernatant, the wash solution, or both may be different for each impurity.

[0098] 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 the steps of: (i) providing a feed mixture comprising at least two metals, said feed mixture being one of an oxidized feed, a reduced feed or an unoxidized feed; the oxidation feed has more of the at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2; the reduced feed has more of the at least two metals in an oxidation state less than 2 than in an oxidation state greater than 2, or has substantially all of the at least two metals in an oxidation state of 2 and at least a portion of the at least two metals in sulfide form; and the unoxidized feed has substantially all of the at least two metals in oxidation state 2 and substantially none of the at least two metals in sulfide form; treating the feed mixture with an aqueous solution to form a leachate containing the at least two metals, the aqueous solution having a pH of about 1 to about 7; If the feed mixture is an oxidation feed, the treatment additionally includes the addition of a reagent comprising a reducing agent; and If the feed mixture is a reduced feed, the treatment additionally includes the addition of a reagent comprising an oxidizing agent; This results in a leachate containing at least two metals in oxidation state 2. providing an aqueous feed solution containing the at least two metals, the aqueous feed solution being a leachate; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, so as to co-precipitate the at least two metals from the feed solution; Includes.

[0099] In one embodiment, the at least one impurity in the coprecipitate may be controlled through selective precipitation. 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% of the initial amount of the at least one impurity may be present in the aqueous feed solution that precipitates into the coprecipitate. This may be particularly the case for alkaline earth metals such as Ca and Mg.

[0100] In one embodiment, at least one impurity may precipitate by a phenomenon such as adsorption, absorption, substitution, atomic replacement, phase formation, secondary phase formation, mixed phase formation, co-precipitation, or liquid entrainment. Alkali metals (such as Li, Na, K), ammonia / ammonium, sulfur (in the form of sulfates or sulfites), and to a lesser extent alkaline earth metals, Zn, Cu, may be removed using high purity water washes, acid washes, caustic washes, sodium carbonate washes, ammonia washes, 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%, less than 1% of these species may be present in the final coprecipitate relative to the amount in the aqueous feed solution.

[0101] In step (i), one or more impurities may be at least partially (in particular partially) separated and / or removed from the aqueous solution comprising at least two metals (in particular nickel, cobalt and manganese) in any suitable manner, for example as described elsewhere in this application.

[0102] Thus, in a further embodiment, there is provided a method for producing a coprecipitate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising: (i) providing an aqueous feed solution containing said at least two metals and at least one impurity, and optionally removing and / or separating one or more impurities from said aqueous feed solution; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally from about 6.2 to about 10, or from about 6.2 to about 9.2, so as to co-precipitate said at least two metals from the feed solution.

[0103] In yet another embodiment, a method is provided for producing a co-precipitate comprising at least two metals selected from nickel, cobalt and manganese, the method comprising: (i) providing a feed mixture comprising at least two metals, said feed mixture being one of an oxidized feed, a reduced feed or an unoxidized feed; the oxidation feed has more of the at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2; the reduced feed has more of the at least two metals in an oxidation state less than 2 than in an oxidation state greater than 2, or has substantially all of the at least two metals in an oxidation state of 2 and at least a portion of the at least two metals in sulfide form; and the unoxidized feed has substantially all of the at least two metals in oxidation state 2 and substantially none of the at least two metals in sulfide form; treating the feed mixture with an aqueous solution to form a leachate comprising the at least two metals, the pH of the aqueous solution being such that the leachate has a pH of about 1 to about 7; If the feed mixture is an oxidation feed, the treatment additionally includes the addition of a reagent comprising a reducing agent; and If the feed mixture is a reduced feed, the treatment additionally includes the addition of a reagent comprising an oxidizing agent; This results in a leachate containing at least one metal in oxidation state 2. said aqueous feed solution being a leachate, and optionally removing and / or separating one or more impurities (or at least a portion of said at least one impurity) from the feed solution to provide an aqueous feed solution containing said at least two metals and at least one impurity; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, to co-precipitate said at least two metals from the feed solution (or to provide (a) a co-precipitate comprising said at least two metals; and (b) a supernatant comprising at least a portion of said at least one impurity).

[0104] The step of removing and / or separating one or more impurities may comprise removing and / or separating one or more impurities from the leachate.

[0105] A suitable technique for separating and / or removing impurities to a desired extent (or range) may be selected by one 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 an embodiment, at least one technique selected from the group consisting of decantation, filtration, centrifugation, cementation and sedimentation, or a combination thereof may 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.

[0106] In another example, at least a portion of the impurities may be in liquid (or dissolved) form. In one embodiment, the 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 a combination thereof; in particular, ion exchange, precipitation and adsorption, or a combination thereof; or solvent extraction, ion exchange, precipitation, adsorption and absorption, or a combination thereof. Exemplary liquid impurities include iron, copper, zinc, calcium, magnesium, chromium, fluorine, lead, cadmium, silicon, and aluminum; in particular, iron, copper, zinc, calcium, magnesium, silicon, and aluminum.

[0107] Ion exchange may be used to remove at least one impurity, particularly at least one metalloid or metal (liquid) impurity, or alkaline earth metal (liquid) impurity. Exemplary impurities that may be removed using ion exchange may include at least one selected from the group consisting of magnesium, calcium, aluminum, iron, zinc, copper, chromium, cadmium, and scandium, particularly at least one selected from the group consisting of aluminum, iron, zinc, copper, chromium, cadmium, and scandium. Ion exchange may be used to remove at least some of the zinc. Ion exchange may be performed in at least two washing steps, particularly two washing steps. Ion exchange may be performed at a temperature of 20°C to 60°C, or about 30°C to 50°C, or 20°C to 40°C, or 40°C to 60°C; for example, 20, 30, 40, 50, 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.

[0108] The removal and / or separation of impurities may be performed using a combination of techniques to remove solid and / or liquid and / or gaseous impurities. Thus, the removal and / or separation of impurities may include a solid impurity removal and / or separation step and a liquid impurity removal and / or separation step. The removal and / or separation of impurities may include a gaseous impurity removal and / or separation step.

[0109] In one embodiment, the removal and / or separation of impurities may be performed using at least one vessel. The at least one vessel may be one or two vessels. The vessel may be a settling vessel and may be configured to settle liquid (which may include entrained solids) therein. The vessel may include at least two outlets. The vessel may include an upper outlet at an upper portion of the vessel to provide an outlet for liquid and a lower outlet at a lower portion of the vessel to provide an outlet for settled solids.

[0110] In one embodiment, step (i) may be carried out using multiple vessels. In one embodiment, step (i) is carried out using at least two vessels (or mixing vessels); in particular, two vessels (or mixing vessels). In one embodiment, the removal and / or separation of impurities is carried out using at least two vessels (or settling vessels), in particular, two vessels (or settling vessels).

[0111] In one embodiment, a mixture (or said feed mixture) comprising at least one or two of nickel, cobalt and manganese is added to the aqueous solution in the first mixing vessel, which is specifically stirred. The solution (including entrained solids) leaves the first mixing vessel via the first settling vessel liquid outlet and enters the first settling vessel via the first settling vessel liquid inlet. The first settling vessel includes at least an upper outlet at the top of the vessel to provide an outlet for the liquid and a lower outlet at the bottom of the vessel to provide an outlet for the settled solids. The liquid leaving the first settling vessel via the upper outlet may proceed to step (ii) of the method of the first aspect or to remove liquid impurities in the solution (as a further part of step (i) of the method of the first aspect). The liquid / solids leaving the first settling vessel via the lower outlet may flow to the second mixing vessel via the second mixing vessel inlet. A reducing or oxidizing agent and a leaching agent may be added to the second mixing vessel. In some instances, there is no settling vessel and the solution may be directly filtered. The second mixing vessel may be agitated. The solution (including entrained solids) leaves the second mixing vessel via the second mixing vessel liquid outlet and enters the second settling vessel via the second settling vessel liquid inlet. The second settling vessel includes at least an upper outlet at the top of the vessel to provide an outlet for the liquid and a lower outlet at the bottom of the vessel to provide an outlet for the settled solids. The liquid leaving the second settling vessel via the upper outlet may flow to the inlet of the first mixing vessel. The liquid / solids leaving the second settling vessel via the lower outlet may be disposed of, for example after passing through a screw press. The advantage of this arrangement is that it minimizes the amount of acid and reducing or oxidizing agents remaining in the solution where the nickel, cobalt and manganese have co-precipitated. Furthermore, by maintaining the proper conditions, the amount of iron (and other impurities such as copper and aluminum) in the first mixing vessel may be minimized. In some embodiments, the method may include the use of more than two mixing vessels (or reactors). The method may include controlling the amount of reagent added to any of the mixing vessels.

[0112] The method may include adding one or more of cobalt, manganese, nickel to the feed solution or leach 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 desired 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 desired molar ratio of nickel:manganese may include 1:1 nickel:manganese, 6:2 nickel:manganese, or 8:1 nickel:manganese. In some embodiments, the desired 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 desired 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 desired 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 desired 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 desired 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 molar ratio may be the nickel:cobalt:manganese ratio or nickel:cobalt ratio or nickel:manganese ratio or cobalt:manganese ratio in the coprecipitate. Not all of the nickel, cobalt, or manganese in the feed solution will precipitate. Those skilled in the art will be able to select the appropriate ratio based on the desired application and the desired ratio of nickel:cobalt:manganese in the final material (e.g., cathode material).

[0113] The one or more of cobalt, manganese, nickel added to the solution may be in any suitable form. One or more cobalt-, manganese-, or nickel-containing compounds may be added. For example, the cobalt, manganese, and nickel added may be in the form of one or more sulfates, hydroxides, or carbonates, or mixtures thereof, in particular CoSO4, NiSO4, and / or MnSO4. In some embodiments, the feed mixture may be produced by combining separate feed mixtures, each independently an oxidized feed, a reduced feed, or an unoxidized feed, thereby producing a composite feed for use in the presently described method. In other embodiments, more than one feed mixture, each independently an oxidized feed, a reduced feed, or an unoxidized feed, may be used to produce more than one leachate by the methods described herein, and the more than one leachate may then be combined in any suitable ratio to provide a composite leachate. In one embodiment, metals other than Ni, Co and Mn (in any suitable form) may be added to the leachate or aqueous feed solution. This assists in the formation of co-precipitates with other metals present.

[0114] Step (ii) of the method produces a coprecipitate 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 of nickel, cobalt and manganese.

[0115] In one embodiment, at least one metal (particularly at least two metals, more particularly all of nickel, cobalt and manganese) in the coprecipitate is derived from the (leached) feed mixture. In one embodiment, the feed mixture may be a combined multiple feed mixture. In one embodiment, each of the multiple feed mixtures may be derived from a different source.

[0116] The pH of the coprecipitation step is from about 6.2 to about 11, or from about 6.2 to about 10.5, or from 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, a pH of 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. If the feed solution in which at least two metals are co-precipitated is relatively pure, a pH of about 9 to 9.2 may be advantageous.

[0117] The inventors have advantageously found that a pH range of about 7.0 to about 8.6, or 6.2 and 8.6, may result in less co-precipitation or inclusion of unwanted impurities, such as, for example, magnesium and / or calcium salts, than would be the case if a higher pH range were used, although the choice of pH may depend on what impurities are present and their concentrations. For example, magnesium generally begins to precipitate from solution as a hydroxide or oxide above a pH of about 8.5, and calcium generally begins to precipitate from solution as a hydroxide or oxide above a pH of about 10.0 (however, complete precipitation of these impurities is not achieved until a higher pH is achieved, and partial precipitation of these elements may be achieved at lower pH depending on the method of precipitation). Thus, co-precipitation may be performed even at a pH where some impurities begin to precipitate (or deposit). However, the relative amounts of precipitation of impurities may be controlled so as not to adversely affect the performance of the battery material, or to achieve a desired amount of co-precipitated impurities, or to achieve a desired battery material performance.

[0118] A suitable reagent (such as a base) may be used to adjust the pH. Examples of reagents (or bases) may include alkali or alkaline earth hydroxides, such as sodium hydroxide. However, the base may also be nickel, cobalt and / or manganese-containing materials such as fresh solids (e.g. hydroxides, carbonates, hydroxyl carbonates), or nickel, cobalt and manganese precipitates (particularly hydroxide precipitates, such as those produced by step (ii)).

[0119] Step (ii) may be carried out at any suitable temperature or pressure. Step (ii) may be carried out at a temperature and pressure at which the feed solution is in liquid form. In one embodiment, step (ii) is carried out at a temperature of about 15°C to about 25°C, for example at about room temperature. In one embodiment, step (ii) is carried out at a temperature less than about 100°C, or less than about 90, 85, 80, 70, 60 or 50°C. In another embodiment, step (ii) is carried out at a temperature greater than about 30°C, or greater than about 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C. In one embodiment, step (ii) is carried out at a temperature of about 25°C to about 100°C, or about 40°C to 95°C, 50°C to 95°C, 60°C to 90°C, or 70°C to 90°C. In one embodiment, step (ii) is carried out at a temperature of about 80°C. In another embodiment, step (ii) is carried out at atmospheric pressure.

[0120] Step (ii) may be carried out using any suitable base. In an embodiment, the base may be a carbonate, bicarbonate, hydroxide, ammonia, or a mixture thereof. It may be ammonia. A suitable carbonate may include a carbonate selected from the group consisting of ammonium carbonate, sodium carbonate, potassium carbonate, lithium carbonate, or a mixture thereof. A suitable bicarbonate may be selected from the group consisting of sodium bicarbonate, ammonium bicarbonate, or a mixture thereof. A suitable bicarbonate is ammonium bicarbonate. A suitable hydroxide is ammonium hydroxide or sodium hydroxide.

[0121] The at least two metals may be co-precipitated in any suitable form, such as in the form of oxides, hydroxides, carbonates and / or hydroxyl carbonates.

[0122] The at least two metals can be all three of nickel, cobalt, and manganese. They can be co-precipitated in any suitable molar ratio. Exemplary molar ratios can 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 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.

[0123] Step (ii) may include separating the coprecipitate from the supernatant. Such separation may include one or more of decanting or filtration. Separation may include resuspending the decanted or filtered coprecipitate in a solution. Separation may include washing the decanted or filtered solids with a solution.

[0124] In one embodiment of the method of the first aspect, following step (ii), the coprecipitate (particularly nickel, cobalt and manganese) may be washed. This may dissolve and / or remove impurities present in the initially (or initially) formed coprecipitate. The washing may be carried out in at least one washing step (or at least two washing steps), for example at least one resuspension washing step. Impurities in the initially formed coprecipitate may be present by association or adsorption, and washing may be required to remove such impurities even if they have not substantially precipitated. In one embodiment, the washing may be an aqueous solution (particularly an aqueous solution of relatively high purity such as distilled water), or a solution (particularly an aqueous solution) containing a base, acid or alkaline reagent (which may achieve the desired removal of the impurity elements). The washing step may include multiple washing steps. The multiple washing steps may utilize different washing solutions. This may aid in the removal of various impurities. These washing solutions may remove contaminated solutions with solids, may react with solids to remove impurities that have partially coprecipitated, or may be both.

[0125] In one embodiment of the method, following step (ii), the coprecipitate (or precipitated nickel, cobalt and manganese) may be mixed with lithium. The lithium and coprecipitate (or nickel, cobalt and manganese) may then be calcined. This may form a cathode active material (CAM). The coprecipitate may be for providing an NMC material for use as a cathode active material (CAM) in a new battery.

[0126] In one embodiment, the calcined lithiated coprecipitate may provide a battery performance of greater than 10 mAh / g, or greater than 20, 50, 70, 100, 120, 130, 140, 150, 160, 170, 180, 190, 200 mAh / g. In this embodiment, the electrochemical performance is defined by the first cycle capacity as measured in a coin cell half-cell battery test conducted at a voltage range of 3.0 to 4.4 V and a charge / discharge rate of 0.2 C.

[0127] In another embodiment of the process of the first aspect, step (ii) may be followed by scavenging (or removing or scavenging) any nickel and / or cobalt and / or manganese remaining in the supernatant by precipitation and / or ion exchange.

[0128] The feed solution may contain one or more impurities either before or after the step of removing the one or more impurities. These impurities include Ca 2+ , Mg 2+ , Li + , Na + , K + , NH4 + ,SCIENCE FICTION - and Cl - In particular, Ca 2+ , Mg 2+ , Li + , Na + , K + ,SCIENCE FICTION - and Cl - Other impurities such as iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, zirconium, titanium may additionally or alternatively be present. Impurities may be present in the feed solution at levels that, if included in the final coprecipitate, would adversely affect the performance of the CAM produced therefrom.

[0129] In one embodiment, the method described herein may include optionally treating a feed solution containing at least two metals selected from Ni, Co and Mn to remove some impurities, and optionally mixing the resulting solution with a sufficient amount of other Ni- and / or Co- and / or Mn-containing solutions to achieve the required Ni:Mn:Co ratio (or Ni:Co, Ni:Mn, or Co:Mn ratio) in the solution. The coprecipitate may be filtered, washed, and optionally selectively precipitated from the solution in the presence of any remaining impurities such that the cleaned coprecipitate may be suitably pure with respect to impurities and, after further processing, have suitable properties such that sufficient performance as a battery material may be achieved.

[0130] In one embodiment, the precipitation of the coprecipitate is carried out in the presence of some 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 these impurities appearing in the coprecipitate may be controlled through control of the upstream impurity removal or separation steps, and control of the precipitation step and subsequent precursor washing and cleaning steps, such that these impurities do not appear in the initially formed coprecipitate, or appear in the initially formed coprecipitate but are subsequently washed or removed, or they appear in the final coprecipitate in a concentration and form that achieves sufficient performance of the precursor material in its intended use as a battery cathode material. In this context, the "initial formed coprecipitate" is understood herein to refer to the material initially precipitated from the aqueous feed solution after pH adjustment, and the "final coprecipitate" to refer to the solid material generated from the initially formed coprecipitate after any subsequent purification steps (e.g., washing, drying) as described herein. The final coprecipitate may then be used as a precursor material for lithium ion battery production. In one embodiment, the coprecipitate described herein is the initially formed coprecipitate.

[0131] The conventional or standard approach to producing precursor materials (or substances) is to start with very high purity Ni or Co or Mn material such as sulfate, metal salt, hydroxide, oxide, carbonate, and dissolve this material in a sulfate solution. The three element solutions are then mixed together to achieve the required ratio of Ni:Co:Mn. The resulting solution contains no or only small amounts of impurity elements. This NiMnCo solution can be mixed with an ammonia-containing solution, as ammonia can act as a complexing agent to favorably mediate the precipitation reaction. The precursor is then precipitated using sodium hydroxide or sodium carbonate, or a combination of said sodium hydroxide or ammonium hydroxide and carbonate. This causes the precipitation of a mixed Ni / Co / Mn-containing oxide or carbonate, or a mixture of oxides and carbonates. The precipitated material is then filtered and washed with water. It may also be washed or mixed again, sometimes with more sodium carbonate solution to extract any remaining sulfate ions. In this way, a typical precursor material with adequate battery performance is produced from a very high purity feed material.

[0132] The primary reason for such a standard approach is that the manufacture of battery precursor materials is believed to require very high purity feed materials to avoid contamination of the battery materials with any impurity elements that may adversely affect the performance of the battery.

[0133] However, the inventors have surprisingly discovered that some elements can be present during the precursor manufacturing process without adversely affecting the performance of the battery material. This means that it is possible to use feed materials and processes that introduce these 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 aid in the co-precipitation process (e.g., when the at least one impurity includes sodium and potassium salts).

[0134] The materials used to prepare the aqueous feed solution used in the method of the present invention may include those discussed in the co-pending application referenced above. They may also include Ni or Co or Mn materials that may also include one or more impurities, but do not include significant amounts of more than one Ni or Co or Mn. In an embodiment, at least one of the Ni, Co or Mn materials may include at least one impurity. Thus, the selective leaching conditions discussed in the co-pending application above also apply herein to the individual materials used. These impurities may be removed from the aqueous feed solution prior to the pH adjustment step to a concentration such that sufficient performance as a battery material is achieved by the final co-precipitate. The presence of some of these impurities may actually improve the performance of the battery material in some instances.

[0135] Alkaline metals such as Li(I), Na(I) and K(I) are generally highly soluble (or soluble) in acidic solutions and do not exhibit stabilization or oxidation precipitation behavior, so they typically dissolve under the leaching conditions used to prepare the aqueous feed solution. Alkaline earth metals such as Mg(II) generally behave similarly. Alkaline earth metals such as Ca(II) are also generally soluble, however limited to relatively low concentrations in sulfuric acid by the solubility of various sulfate compounds. Thus, these elements may be present in the feed solution. However, alkali metals such as Li, Na and K are generally soluble in aqueous solutions up to pH values ​​above 12, and therefore generally do not precipitate or co-precipitate significantly. Alkaline earth metals such as Mg may precipitate at about pH 8-9 as hydroxides or carbonates. Alkaline earth metals such as Ca may precipitate at about pH 8-9 as carbonates and at about pH 9-10 as hydroxides. Thus, careful control of variables such as pH, optional addition of base, initial concentration of elements in solution, final concentration of elements in solution during the coprecipitation step (and other variables that may affect this precipitation behavior, including, for example, temperature, reagent addition rates, reagent concentrations, and washing conditions), and optional selection of precipitation reagents, may allow control of the behavior of these elements during the formation of the coprecipitate (or of the final coprecipitate, if multiple precipitation and / or multiple washing steps are used). Although Li, Na, K are soluble up to pH values ​​higher than those at which the coprecipitate precipitates, these elements may substantially contaminate the solid product if selective precipitation and washing is not performed, especially when the amount of these elements in the supernatant after coprecipitate precipitation is higher than if reagents were added solely for the precipitation of the coprecipitate itself.

[0136] 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 the feed material to prepare the feed solution, and the detrimental effect of any of these elements on the battery performance can be avoided by the methods described herein, which may include controlled precursor precipitation, washing and washing steps, rather than removing these impurities only by selective dissolution and impurity removal and / or separation steps.

[0137] Step (ii) of the methods described herein may be carried out, for example, using any one or more of sodium carbonate, sodium hydroxide, potassium carbonate, potassium hydroxide, lithium carbonate, lithium hydroxide, ammonia, ammonium carbonate and ammonium hydroxide as a precipitation reagent (e.g., to adjust the pH of the feed solution).

[0138] Step (ii) of the methods described herein may be carried out for any suitable period of time, for example, step (ii) may be carried out for at least 1 hour, 2 hours, 4 hours, 8 hours, 16 hours, 24 hours, 36 hours or 48 hours.

[0139] Careful control of many other factors such as the concentration of Ni, Co and / or Mn in the feed solution, the rate of addition of Ni, Co and Mn solutions, the rate of adjustment of pH, temperature, reaction time, aging time, and the presence of complexing ions such as ammonia, can be used to perform precipitation of precursor materials at a target ratio of Ni:Mn:Co to produce an initial co-precipitate that can then be filtered and washed to achieve a battery precursor material with sufficient performance. After the initial co-precipitate is formed, the environment in which the at least two metals are present can be controlled to minimize or ameliorate oxidation of the at least two metals, or to maximize oxidation of the at least two metals. Such control can include controlling the atmosphere surrounding the at least two metals or the co-precipitate, or the initial or final co-precipitate. Control of the atmosphere can include controlling the oxygen concentration in the atmosphere or any gas phase, the pressure of the atmosphere or any gas phase.

[0140] For a suitable coprecipitate cathode active material (precursor material) in the hydroxide form, it has been believed that the amount of nickel, manganese and / or cobalt in the coprecipitate should preferably be at least about 60% on a dry solids basis. The other approximately 40% can be oxides, or hydroxides, or carbonates. In this 60% material, the upper limit for impurities is generally 50% or less than SO4. 2- , F -, Cl - For anion species such as these (but excluding the oxides, hydroxides, and carbonates mentioned above), the concentration is 3000-4000 ppm, for alkali metals and alkaline earth metals (excluding lithium) (or alkaline earth metals), the concentration is 300 ppm, and for metals and metalloids, the concentration is 50 ppm. Thus, anions (particularly excluding hydroxides, oxides, and carbonates) may have a molar (or mass) ratio of NMC to impurities of about 200:1. Ca and Mg (or Ca, Mg, Na, and K) at 300 ppm provide a molar (or mass) ratio of NMC to impurities in the solid of about 2000:1, and Fe at 50 ppm, for example, provides a molar (or mass) ratio of NMC to impurities of about 12,000:1.

[0141] The total amount of nickel, manganese and / or cobalt in the aqueous feed solution can 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.

[0142] In one embodiment, the amount of the at least two metals in the coprecipitate is controlled to be less than 100% of the amount of the at least two metals in the aqueous feed solution. In one embodiment, the amount of the at least two metals in the coprecipitate is controlled to be less than 99%, less than 95%, less than 90%, less than 80%, or less than 70%, or less than 50%, or less than 20% of the amount of the at least two metals in the aqueous feed solution. The amount of nickel, manganese, and cobalt in the coprecipitate relative to the amount in the aqueous solution can be different percentages from each other or can be the same.

[0143] In one embodiment, the supernatant of 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.

[0144] 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 100,000 ppm or less, or 80,000 ppm or less, or 60,000 ppm or less, or 50,000 ppm or less, or 40,000 ppm or less, or 30,000 ppm or less, or 20,000 ppm or less, or 15,000 ppm or less, or 10,000 ppm or less, or 7,000 ppm or less, or 5,000 ppm or less, or 4,000 ppm or less, or 3,000 ppm or less, or 2,500 ppm or less, or 2,000 ppm or less. In another embodiment, the molar ratio of the at least two metals to the alkali metal impurity (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 the at least two metals to the alkali metal impurity (or at least one alkali metal impurity) in the aqueous feed solution can 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 the at least two metals to the alkali metal impurity (or at least one alkali metal impurity) in the aqueous feed solution can be from about 1:10 to 23,000:1, or from about 1:10 to 100,000:1, or from about 1:10 to 300,000:1.In another embodiment, the molar ratio of the at least two metals to the alkali metal impurity (or the at least one alkali metal impurity) in the aqueous feed solution can be from about 1:50 to 23,000: 1, or from about 1:50 to 100,000: 1, or from about 1:50 to 300,000: 1. In one embodiment, the alkali metal impurity does not originate from the precipitation reagent.

[0145] In one embodiment, the percentage of alkali metal present in the aqueous feed solution that gives rise to the coprecipitate is less than 100%, or less than 99%, or less than 90%, or less than 50%, or less than 20%, or less than 1%.

[0146] In another embodiment, the coprecipitate contains less than 10 ppm, 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 of alkali metal in the dry solids.

[0147] In one embodiment, the anionic species impurities (F - and Cl -The concentration of (but in particular excluding said oxides, hydroxides, sulfates or carbonates) (or at least one anionic species impurity) is not more than 100,000 ppm, or not more than 80,000 ppm, or not more than 60,000 ppm, or not more than 50,000 ppm, or not more than 40,000 ppm, or not more than 30,000 ppm, or not more than 20,000 ppm, or not more than 10,000 ppm, or not more than 5,000 ppm, or not more than 4,000 ppm, in particular not more than 3,000 ppm, or not more than 2,500 ppm, or not more than 2,000 ppm. In another embodiment, the molar ratio of the 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 the at least two metal to anionic species impurities (or at least one anionic species impurity) in the aqueous feed solution can 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.

[0148] In one embodiment, the percentage of anionic species present in the aqueous feed solution that gives rise to the coprecipitate is less than 100%, or less than 99%, or less than 90%, or less than 50%, or less than 20%, or less than 1%.

[0149] In another embodiment, the coprecipitate may contain less than 10 ppm, 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 of anions (excluding hydroxide, oxide, carbonate, or bicarbonate anions) in the dry solids.

[0150] Without wishing to be bound by theory, the inventors believe that phenomena such as liquor entrainment and atomic displacement may facilitate the desorption of some anions (especially F - , PO4 3- , Cl - , SO4 2- and NO3 - It is believed that anions such as 1,2-dichlorophenyl 1,4-dichlorophenyl 1,5-dichlorophenyl 1,6-dichlorophenyl 1,7-dichlorophenyl 1,8-dichlorophenyl 1,9 ...

[0151] 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. less than 0 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 20 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 further embodiments, 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 20,000 ppm or greater, or greater than 10,000 ppm, or 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 50 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 further embodiments, the molar ratio of the at least two metals to the alkaline earth metal impurity (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 greater than about 500:1, or greater than about 1000:1, or greater than about 1500:1, or greater than about 2000:1, or greater than about 5000:1, or greater than about 10000:1. In one embodiment, the molar ratio of the at least two metals to the alkaline earth metal impurity (or at least one alkaline earth metal impurity) in the aqueous feed solution is from about 300,000,000:1 to about 1:10; or greater than about 1:10, or greater than 1:1. In one embodiment, the molar ratio of the 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 10000:1. In one embodiment, the ratio (by weight) of the at least two metals to alkaline earth metals in the aqueous feed solution is less than 10,000:1. In one embodiment, the ratio (by weight) of the at least two metals in the aqueous feed solution to calcium is less than 10,000: 1. In a further embodiment, the ratio (by weight) of the at least two metals in the aqueous feed solution to magnesium is less than 10,000: 1. In one embodiment, the ratio (by weight) of the at least two metals in the aqueous feed solution to metals other than nickel, cobalt, manganese and alkaline earth metals and / or alkali metals is less than 6,000: 1.

[0152] In one embodiment, the percentage of alkaline earth metal species present in the aqueous feed solution reported 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 0.1.

[0153] In another embodiment, the coprecipitate contains less than 10 ppm, 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 of alkaline earth metals in the dry solids.

[0154] In further embodiments, the concentration of the metal and metalloid impurities (or at least one metal or metalloid impurity) in the aqueous feed solution is less than 250 ppm, in particular less than 50 ppm. In further embodiments, the concentration of the metal and metalloid impurities (or at least one metal or metalloid impurity) in the aqueous feed solution is greater than 1 ppb, in particular 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 selected from the group consisting of iron, aluminum, copper, zinc, cadmium, chromium, silicon, lead, zirconium, scandium, titanium, and the like. In one embodiment, the molar ratio of the at least two metals to the metal impurities 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 the at least two metals to the Fe impurity 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 the at least two metals 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 one embodiment, the molar ratio of the at least two metals to Al 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 the at least two metals to Al impurities is less than 10,000:1, or less than 20,000:1, or less than 100,000:1.

[0155] In one embodiment, the ratio of the 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 the 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 the 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 the 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 the 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 the at least two metals in the aqueous feed solution to zirconium (by weight) is less than 500,000:1.

[0156] In one embodiment, the percentage of metal and metalloid species present in the aqueous feed solution that gives rise to the coprecipitate is less than 90%, or less than 10%, or less than 1%.

[0157] In another embodiment, the coprecipitate contains less than 10 ppm, 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 of metal and metalloid species in the dry solids.

[0158] However, the inventors have found that in some cases the above specification can be somewhat arbitrary. For example, Ca and Mg in the final co-precipitate up to 500 ppm or 1000 ppm do not appear to have a significant effect on the performance of the battery material. Therefore, lower ratios of these elements appear to be acceptable. It is believed that calcium levels of at least two metals:Ca up to 1000:1 can be present in the co-precipitate without adverse effects.

[0159] As described elsewhere herein, when the method of the present invention is used to prepare the final coprecipitate, precipitation of many of these elements can be largely avoided, while some degree of coprecipitation is relatively unavoidable for others, however, in the latter cases, the coprecipitation of the impurities may have little effect on the performance of the final coprecipitate or may provide acceptable performance of the final coprecipitate when used in a battery material.

[0160] Using Mg as an example, it has been possible to achieve co-precipitation of Mg at 100%, near 100%, less than 100%, less than 50%, and substantially less than 10%. Assuming 1% Mg precipitation from solution, and precipitation of Ni, Co, Mn, a 10:1 ratio of at least two metals:Mg in the feed solution will allow a 1000:1 ratio of at least two metals:Mg in the coprecipitate to be achieved.

[0161] The inventors have found that co-precipitation of even less Mg is possible and have shown that a feed solution containing 1:17 two metals:Mg is viable to create an acceptable co-precipitate. Thus, a feed solution having at least two metals:Mg up to 1:10 or even 1:50 may provide an acceptable co-precipitate at the desired Mg ratio. Also, a feed solution having at least two metals:Mg up to 1:1 or even 1:10 may provide an acceptable co-precipitate. Similar ratios may also be achievable for Ca.

[0162] For other elements such as Fe, the co-precipitation can be 100%, near 100%, or less than 100%. With 100% co-precipitation of Fe and 100% precipitation of the at least two metals, a ratio of at least two metals:Fe in the solution of 12000:1 would be the upper limit to achieve a ratio of at least two metals:Fe in the initial co-precipitate of 12000:1, which corresponds approximately to a concentration target of 50 ppm in the final co-precipitate. In this case, the method can still process this aqueous feed solution to produce a co-precipitate. However, if co-precipitation of less than 100% Fe is performed, the ratio of at least two metals:Fe in the aqueous feed solution can be lower than 12,000:1, and less than 50 ppm Fe can be achieved in the co-precipitate. Also, more than 50 ppm of iron or other elements can be tolerated in the final co-precipitate without significant impact on the performance of the battery material.

[0163] Conversely, it is highly unlikely that impurity-free feed solutions are readily available or will be used in the present invention. A practical minimum for each impurity, or combination of impurities, present may be about (or approximately) 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.

[0164] In one embodiment, the amount of at least one impurity relative to the at least two metals in the coprecipitate is less than the amount of at least one impurity relative to the at least two metals in the aqueous feed solution. In one embodiment, the coprecipitate may contain less than 100%, in particular less than 90%, or less than 80%, or less than 70%, or less than 60%, or less than 50%, or less than 40%, or less than 30%, or less than 20%, or less than 10% of the at least one impurity in the aqueous feed solution. In one embodiment, the coprecipitate may contain less than 100% of the alkali metals and anions in the aqueous feed solution, in particular less than 90%, or less than 80%, or less than 70%, or less than 60%, or less than 50%, or less than 40%, or less than 30%, or less than 20%, or less than 10% of the alkali metals and anions in the aqueous feed solution. In one embodiment, the coprecipitate may comprise less than 100% of the alkaline earth metals in the aqueous feed solution, in particular less than 90%, or less than 80%, or less than 70%, or less than 60%, or less than 50%, or less than 40%, or less than 30%, or less than 20%, or less than 10% of the alkaline earth metals in the aqueous feed solution. In one embodiment, the coprecipitate comprises less than 100% of the alkali metals and ionic species in the aqueous feed solution; the supernatant comprises at least 0.1% of the alkaline earth metals, less than 100% of the alkali metals and ionic species and less than 100% of metals other than alkali metals and alkaline earth metals in the aqueous feed solution.

[0165] In one embodiment, at least 1% and up to 100% of the nickel, cobalt and / or manganese is derived from impurity sources (wherein the ratio of nickel, cobalt and / or manganese: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).

[0166] The inventors have advantageously found that by processing the impurity solution, the level of beneficial impurities in the final product can be controlled. In prior art processes, such beneficial impurities (such as Mg or Al) can be added separately as dopants. The method of the present invention can make it possible to avoid this cost while still producing an acceptable coprecipitate. This allows a wide variety of feeds to be used. This is also important in the case of some particular feed materials, such as aluminum and magnesium, that contain impurities that can also be used as dopants, or when using regenerative battery feed materials, which may contain impurities that can also be used as dopants, and the use of the described method can make it possible for these impurities to be present in the supernatant and in the coprecipitate at the desired concentration, controlled in such a way that they report. In all these cases, a substantial portion of the desired dopant element can come from the feed material that contains at least one metal and at least one impurity.

[0167] As previously mentioned, a typical prior process was to dissolve highly purified individual nickel, cobalt and manganese sulfate salt raw materials in a solution at a specific ratio and purity and perform co-precipitation with the solution. In such a process, the feedstock of such salts may have, for example, 5 ppm or less of impurities. Two examples of specifications required for the use of nickel sulfate hexahydrate salt in the preparation of NMC materials are shown in the table below. Given the very low allowable impurity concentrations of these salts for the production of NMC materials, the solution used for NMC precipitation would have an equally low NMC:impurity ratio, as shown in Table 2. Avoiding the cost of purifying the feedstock to this very low concentration of impurities is a major advantage of the present invention, as it allows the production of NMC materials from materials containing more impurities without the need to perform expensive steps to remove said impurities from the solution prior to NMC production.

[0168] [Table 1]

[0169] [Table 2]

[0170] In some prior art documents, the feed material used to prepare the solution for NMC coprecipitation is an NMC-like material or material that not only contains at least one of Ni, Co and Mn elements, but may also contain some impurity elements, and that has previously been or can be used as a battery cathode containing at least one of Ni, Co and Mn elements. In such cases, there are almost no impurities in the feed material, or the impurities present in the feed material are at low concentrations, making it equivalent to a standard high purity feed material. In such cases, the coprecipitation may be carried out under non-selective conditions.

[0171] The feed material (or feed mixture in step A) for use in the process may comprise recycled materials, ore products (or products), intermediate ore products, and / or NMC salts containing impurities.

[0172] The recycled materials may include, but are not limited to, spent lithium ion batteries (black mass), spent catalysts containing nickel, cobalt and / or manganese. The recycled materials may include at least one of Co / Mn / Ni and at least one impurity. Many prior art processes do not consider the presence of the following impurities in the black mass: 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 may be substantially or completely removed from the coprecipitates formed by the method of the present application. In some cases, in some recycled materials, impurity elements may be present through contamination or through variations in the composition of the initial lithium ion batteries.

[0173] Ores and ore intermediates containing one or more of nickel, cobalt and manganese may be leached to create an aqueous feed solution suitable for coprecipitation. Such feeds may inherently contain impurities and may include laterites and sulfides (and their flotation concentrates), as well as more processed feeds such as MHP and MSP. To the inventors' knowledge, the production of coprecipitates from such feed materials containing impurities of the type and concentrations present in such ores and ore intermediates has not been contemplated in the prior art.

[0174] The impure NMC salts can be, for example, combinations of pure Co and Mn salts with Ni salts containing at least one impurity, or other combinations of pure and impure salts.

[0175] In one embodiment, step (ii) may include steps of performing the co-precipitation at a lower pH, changing the method of base administration, changing the type of base, adding a precipitant, or adjusting the concentration of at least two metals in the aqueous feed solution. Such steps may help control the selectivity of the co-precipitation. As an example, a carbonate base (such as sodium carbonate) may not be suitable for aqueous solutions containing high concentrations of Ca, since it forms stable CaCO3. In this case, a hydroxide base may increase the selectivity. The method of administration of the base (or base) may include continuous administration, semi-continuous administration, semi-batch administration, batch administration, or a combination thereof. The method of the present invention may also help control the physical properties of the co-precipitate. Such physical properties may include particle size, bulk density, tap density, morphology, shape, and crystallinity.

[0176] In one embodiment, the co-precipitation step (step (ii)) may include adding a precipitating agent to the feed solution. The precipitating agent may be an oxidizing agent, a base, or an organic anion compound. The oxidizing agent and the reducing agent may be as defined elsewhere herein. The organic anion compound may include oxalate. The precipitating agent may be added in a stoichiometric amount relative to the at least two metals (e.g., at least 1, 1.5, 2, 2.5, or 3 equivalents of precipitating agent). The precipitating agent may be added in a sub-stoichiometric amount relative to the at least two metals (e.g., less than 1, 0.9, 0.8, 0.7, or 0.6 equivalents of precipitating agent). The use of a sub-stoichiometric amount of precipitating agent may result in less than 100% recovery of the at least two metals from the feed solution.

[0177] Following the co-precipitation step (step (ii)), the method may additionally include mixing with lithium. It may include calcining. These steps may result in the production of a cathode active material (CAM).

[0178] The oxidation may also be controlled by the addition of an oxidizing reagent to the feed solution (which may include the control or addition of an oxidizing agent in gaseous form) to effect oxidation of one or more of Mn, Co and Ni prior to step (ii) in order to adjust or achieve a certain ratio of these elements in the solids, allowing selectivity of these elements with respect to the impurity elements during the co-precipitation step.

[0179] Once the coprecipitate is formed, it may be isolated by any suitable means to isolate it. These include settling, centrifugation, filtration, decantation, and any combination thereof. The method may include decantation and / or filtration to isolate the coprecipitate. The isolated coprecipitate may then be washed. It may be washed with a suitable washing agent to remove any unwanted impurities. Suitable washes are alkaline washes, water washes, acid washes, or ammonia washes. The alkaline washes may be at a pH greater than about 9, or greater than about 10, 11, 12.

[0180] The coprecipitate may be supplemented with lithium, optionally after washing. Thus, 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 take the form of physically mixing the coprecipitate with lithium. The lithium may be added in a molar ratio of greater than about 1:1 relative to the sum of Ni, Co, and Mn.

[0181] The coprecipitate may be dried. It may be dried at any suitable temperature, for example, about 80 to about 150°C, or about 80 to 100°C, 100 to 150°C, 100 to 130°C, 130 to 150°C, or 90 to 120°C, for example, about 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C, by passing air or other gas through the coprecipitate at the specified temperature, or it may involve allowing the coprecipitate to rest at that temperature. The drying time may be sufficient to achieve a moisture level of less than about 10%, or less than about 5, 2, 1, 0.5, 0.2, or 0.1% by weight. The drying time can be at least about 5 hours, or at least about 6, 7, 8, 9 or 10 hours, or from about 5 to about 20 hours, or from about 5 to 15 hours, 5 to 10 hours, 10 to 15 hours, 15 to 20 hours or 7 to 12 hours, for example, about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 hours.

[0182] In one embodiment, steps (i) and (ii) of the method of the first aspect may be repeated, i.e. the method comprises the steps of: (i) providing an aqueous feed solution containing said at least one metal (or at least two metals) and at least one impurity; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, to provide (a) a coprecipitate comprising said at least one metal (or at least two metals); and (b) a supernatant comprising said at least one impurity; (iii) separating the coprecipitate from the supernatant; (iv) dissolving the coprecipitate in solution to provide a solution in which at least one metal (or at least two metals) is at least partially dissolved; and (v) adjusting the pH of the solution of step (iv) to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2 to provide (a) said at least one metal (or at least two metals) coprecipitate comprising at least two metals; and (b) a supernatant comprising said at least one impurity. may include. In one embodiment, step (iv) may comprise dissolving the coprecipitate in an acidic solution. The characteristics of step (v) are as described above for step (ii). This method advantageously allows for easy 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).

[0183] In one embodiment, the method may further include manufacturing a lithium ion battery using the co-precipitate.

[0184] According to a second aspect of the present invention, there is provided a method for producing a precipitate comprising at least one metal selected from nickel, cobalt and manganese, the method comprising: (i) providing an aqueous feed solution containing said at least one metal; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally from about 6.2 to about 10, or from about 6.2 to about 9.2, so as to precipitate said at least one metal from the feed solution.

[0185] The aqueous feed may comprise at least one impurity. Thus, adjusting the pH of the feed solution may provide a supernatant comprising said at least one impurity. Thus, in one embodiment of the second aspect, there is provided a method of producing a precipitate, the precipitate comprising at least one metal selected from nickel, cobalt and manganese, the method comprising: (i) providing an aqueous feed solution containing said at least one metal and at least one impurity; and (ii) adjusting the pH of the feed solution to about 6.2 to about 11, optionally about 6.2 to about 10, or about 6.2 to about 9.2, to provide: (a) a precipitate comprising said at least one metal; and (b) a supernatant comprising said at least one impurity.

[0186] Features of the second embodiment are as described above for the first embodiment. Where the context permits, a reference to "at least two metals" in the first embodiment may be a reference to "at least one metal" in the second embodiment. Similarly, where the context permits, a reference to a "co-precipitate" in the first embodiment may be a reference to a "precipitate" in the second embodiment.

[0187] In a third aspect, there is provided a co-precipitate (or precipitate) comprising at least two metals selected from nickel, cobalt and manganese, said co-precipitate (or precipitate) being produced by the method of the first or second aspect.

[0188] The present invention is directed to the formation of a coprecipitate containing nickel, manganese and / or cobalt suitable for use as a precursor material for manufacturing lithium ion batteries. Mixtures of Ni, Co and / or Mn containing materials containing some levels of impurities can be at least partially selectively dissolved using, for example, the processes described in this application. The resulting solution can be treated, if necessary, to remove some of the impurities and mixed with sufficient amounts of other Ni and / or Co and / or Mn containing solutions to achieve the required Ni:Mn:Co ratio. The filtered, washed and cleaned product is suitably pure with respect to impurities and has suitable properties to achieve sufficient performance as a battery material after further processing.

[0189] In one embodiment, the coprecipitate has or contains less than about 1000 ppm iron, or less than about 500 ppm iron, or less than about 200 ppm iron, or less than about 100 ppm iron, or less than about 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, or less than 10,000 ppm, or less than 5,000 ppm, or less than 2,000 ppm, or less than 1,000 ppm, or less than 500 ppm, or less than 100 ppm, or less than 50 ppm, or less than 20 ppm, or less than 10 ppm, or less than 5 ppm, of alkaline earth metals. In another embodiment, the coprecipitate contains less than 2,000 ppm, 1,500 ppm, 1,000 ppm, 500 ppm, 200 ppm, 100 ppm, 50 ppm, 20 ppm, 10 ppm, or less than 5 ppm of alkali metal.In another embodiment, the coprecipitate contains less than 2,000 ppm, 1,500 ppm, 1,000 ppm, 500 ppm, 200 ppm, 100 ppm, 50 ppm, 20 ppm, 10 ppm, or less than 5 ppm of metals other than alkali metals and alkaline earth metals.In another embodiment, the coprecipitate contains less than 2,000 ppm, 1,500 ppm, 1,000 ppm, 500 ppm, 200 ppm, 100 ppm, 50 ppm, 20 ppm, 10 ppm, or 5 ppm of metalloids. In another embodiment, the coprecipitate contains less than 10,000 ppm, 5,000 ppm, 3,000 ppm, 2,000 ppm, 1,500 ppm, 1,000 ppm, 500 ppm, 200 ppm, 100 ppm, 50 ppm, 20 ppm, 10 ppm, or 5 ppm of anionic species other than hydroxide or carbonate.

[0190] In a fourth aspect, the present invention provides the use of the coprecipitate of the third aspect for the manufacture of a lithium ion battery.

[0191] Features of the third and fourth aspects of the invention may be as described for the first aspect of the invention.

[0192] According to a fifth aspect of the present invention there is provided a method for producing a leach solution comprising at least two metals selected from nickel, cobalt and manganese, the method comprising: A. providing a feed mixture comprising at least two metals, the feed mixture being one of an oxidized feed, a reduced feed, or an unoxidized feed: the oxidation feed has more of the at least two metals in an oxidation state greater than 2 than in an oxidation state less than 2; the reduced feed has more of the at least two metals in an oxidation state less than 2 than in an oxidation state greater than 2, or has substantially all of the at least two metals in an oxidation state of 2 and at least a portion of the at least two metals in sulfide form; and the unoxidized feed has substantially all of the at least two metals in oxidation state 2 and substantially none of the at least two metals in sulfide form; B. treating the feed mixture with an aqueous solution to form a leachate comprising the at least two metals, the aqueous solution having a pH such that the leachate has a pH of about -1 to about 7 (or about -1 to about 6, or about 1 to about 7, or about 1 to about 6); If the feed mixture is an oxidation feed, the treatment further includes the addition of a reagent comprising a reducing agent; and If the feed mixture is a reduced feed, the treatment includes the addition of a reagent including an oxidizing agent; Thereby, the leachate comprises at least two metals in the oxidation state 2.

[0193] Features of the fifth aspect may be as described above for the first or second aspects.

[0194] According to a sixth aspect of the present invention there is provided a method of producing a leach solution comprising at least two metals selected from nickel, cobalt and manganese, the method comprising contacting a mixture comprising at least two metals with an aqueous solution at a pH such that the leach solution has a pH of about 1 to about 7 (or about 1 to about 6), thereby providing said leach solution comprising said at least two metals in solution; wherein at least a portion of said at least two metals in a feed mixture have an oxidation state of 2.

[0195] The method of the sixth aspect may include 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. Note that this embodiment is similar to the fifth aspect of the invention. In one embodiment, the method of the sixth aspect may include removing one or more impurities from the leachate.

[0196] The features of the sixth aspect of the invention are as described for the fifth aspect of the invention.

[0197] In a seventh aspect, the present invention provides a leachate comprising at least two metals selected from nickel, cobalt and manganese, optionally all three metals, said leachate produced by the process of the fifth aspect.

[0198] In an eighth aspect, the present invention provides a leachate comprising at least two metals selected from nickel, cobalt and manganese, optionally all three metals, said leachate produced by the process of the sixth aspect.

[0199] Any of the features described herein may be combined in any combination with any one or more of the other features described herein within the scope of the present invention.

[0200] In one embodiment, the present specification is directed to the dissolution of certain metals, in particular the dissolution of two or three of nickel, cobalt and manganese. The dissolution may be carried out in an at least partially selective manner. This may involve the use of control of the final pH from about 1 to about 7, or from about 1 to about 6, with the aim of maintaining Ni+Mn, Ni+Co or Mn+Co, or indeed Ni+Mn+Co, with minimal dissolution of impurities and / or minimal loss of Ni, Co or Mn, to produce a solution with approximately the correct ratio for the precipitation of the battery precursor material. The process then removes and / or separates some impurities from the resulting solution so that the resulting solution can be used to produce the battery precursor material. Depending on the initial solid material, this may require the use of a reducing agent, an oxidizing agent, both, or neither. Also, the material does not necessarily have to contain all of the Ni, Mn, Co, or all of the Ni, Mn, Co required for the final product. The process is intended to produce a solution for use in the production of the precursor material.

[0201] One aspect of this process is that a substantial portion of the selected metals are retained together through the leaching and impurity removal or separation steps so that the ratio of Ni:Mn:Co in the resulting leachate can be adjusted and used to precipitate NMC type materials.

[0202] The feed mixture for the present process in certain embodiments may include residues from the SAL process, products from the present process, materials from batteries, other oxide materials such as nickel oxide ores, intermediate nickel products such as MHP (mixed hydroxide precipitates), MCP (mixed carbonate precipitates) or MSP (mixed sulfide precipitates), other sulfide materials such as nickel sulfide ores, nickel sulfide concentrates or nickel sulfide matte, or metallic materials, which may include metallic materials so long as they contain significant amounts of at least two of Ni, Co and Mn.

[0203] These materials can be generally classified according to the oxidation states of the Ni, Co and Mn contained therein. Nickel and cobalt are often present in metallic form, which can be referred to as Ni(0) or Co(0). They can be oxidized to the ionic forms Ni(II) or Ni(III), Co(II) or Co(III). Mn can be present in the form of Mn(0), Mn(II), Mn(III), Mn(IV), Mn(VII). Other oxidation states of these elements can exist but are less common. The inventors have found it convenient to change the oxidation state of the elements to the (II) state in order to dissolve these metals in a relatively selective manner. Thus, any material in which the oxidation state of Ni, Co, Mn is higher than (II) is considered to be oxidized compared to the desired (II) form, and any material having an oxidation state lower than (II) is considered to be reduced compared to the desired (II) form. The reason for obtaining these elements in the (II) state is that in that form, all three metals are appreciably soluble in acidic solutions of sulfuric, nitric or hydrochloric acids from pH about 1 up to pH about 6 or 7. In comparison, (III) or (IV) in the case of Mn are appreciably soluble only in these acidic solutions below pH 3. Obtaining the elements in the (II) state therefore makes it possible to dissolve them in less acidic conditions. This provides selectivity for a number of impurities.

[0204] Residues from the SAL process have most of the Ni as Ni(II), most of the Co as Co(III) or solid mixed Co(II) / Co(III) form, and most of the Mn as Mn(III) or Mn(IV). This is classified as an oxidized feed. Battery cathode materials have most of the Ni as Ni(III), most of the Co as Co(III), and most of the Mn as Mn(III) and Mn(IV). This is classified as an oxidized feed. Nickel oxide ores have Ni as Ni(II) or Ni(III), Co as Co(II) or Co(III), and Mn as Mn(II), Mn(III), and Mn(IV). These can be classified as oxidized feeds. MHP and MCP intermediates have most of the Ni as Ni(II), most of the Co as Co(II), and most of the Mn as Mn(II). These are classified as unoxidized feeds.

[0205] MSP and other sulfide materials have most of their Ni as Ni(II) and Co as Co(II). Typically there is very little Mn associated with the sulfides. Because the Ni and Co in these sulfide materials are bound to sulfur, it is not necessary to oxidize or reduce the Ni or Co to dissolve them, but sulfur must be oxidized to liberate the Ni and Co from the sulfide form. Thus, the sulfide source is classified as a reducing feed.

[0206] The metallic forms will have most of the Ni as Ni(0), most of the Co as Co(0), and most of the Mn as Mn(0), although there may be small amounts of the oxide forms of these elements in the (II) state that are also associated with the metal, and therefore are classified as reduced feeds.

[0207] In general, oxidized feeds will need to be reduced by a suitable reducing agent to allow them to dissolve and form a leachate. Unoxidized feeds will not require significant reducing or oxidizing agents to allow the Ni, Co and / or Mn to dissolve to form a leachate. Reduced feed materials will need to be oxidized by a suitable oxidizing agent to allow them to dissolve to form a leachate.

[0208] A feature of this approach in one embodiment is that in the oxidizing feed, nickel oxide will typically be 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 therefore dissolved in a manner that controls the amount of each element that contributes to the leachate. Also, the choice of reducing agent, or even the use of an oxidizing agent after the reducing agent, can control the extent of dissolution of these metals.

[0209] Furthermore, this behavior allows the reducing reagent to reduce and dissolve significant amounts of the Ni / Co / Mn metals before consuming the reductant and / or reacting with significant amounts of other elements that can be dissolved by reduction reactions. Fe is an example of an element that behaves similarly to Ni and Co; that is, Fe can exist in the Fe(II) and Fe(III) states, with Fe(II) being appreciably soluble in acid below a pH of about 7, while Fe(III) is appreciably soluble only below a pH of about 3. However, control of the reduction through careful control of the rate of reagent addition, amount of reagent addition, choice of reagent, temperature, and other parameters, can be used to stop or minimize the reduction of Fe(III) to Fe(II) until after the majority of the Ni, Co, and Mn have reacted to their (II) forms. Alternatively, the reduction reaction can be followed by the addition of an oxidizing agent that reacts with Fe(II) rather than with Co(II) or Mn(II), or at least with Fe(II) prior to Ni(II) Co(II) and / or Mn(II), and oxidizes Fe(II) back to Fe(III) and back to the solid phase. Thus, selective dissolution of Ni / Co / Mn away from Fe in the Ni / Co / Mn-containing material can be achieved. The selective dissolution step can then be followed by a solid-liquid separation step, such as decantation, centrifugation, sedimentation and / or filtration.

[0210] This approach to controlled reduction and oxidation can also be applied to reducing materials such as sulfides and metal sources of Ni, Co, and Mn. The sulfide material can be reacted with an oxidizing agent to oxidize the sulfide portion and dissolve the Ni, Co, and Mn. The oxidizing agent and dissolution can be controlled so that the Ni, Co, and Mn portions of the material are significantly oxidized and dissolved before other impurity portions of the material are oxidized and / or dissolved, thereby producing a relatively clean solution containing Ni, Co, and Mn. The feed material or solution can also be further oxidized to oxidize and precipitate impurity elements such as Fe before significant amounts of Mn, Co, and Ni are oxidized and precipitated.

[0211] Similarly, after Ni, Co, Mn, to avoid dissolution of other metallic materials that oxidize the precious and platinum group metals, or even more precious metals including copper, lead, tin, the metals can be reacted with an oxidizing agent (e.g., as described above) to oxidize and dissolve the contained Ni / Co / Mn moieties to the (II) state while controlling the oxidation extent. Oxidation can also be used to oxidize and precipitate impurity metals such as Fe, and even to oxidize and precipitate Mn to control the ratio of Ni:Co:Mn in the solution.

[0212] The major leaching impurities commonly associated with these materials are alkali elements (primary considerations are Li, Na, K), alkaline earth elements (primary considerations are Mg, Ca), transition metals (primary considerations are Sc, Ti, V, Cr, Fe, Cu, Zn, Cd), other metals (primary considerations are Al, Sn, Pb), and metalloids (primary considerations are Si, As, Sb).

[0213] Metals such as Li(I), Na(I) and K(I) are highly soluble in acidic solutions and do not exhibit stabilization or oxidative precipitation behavior, and therefore will typically dissolve under the leaching conditions used in the processes described herein. Mg(II) exhibits similar behavior. Ca(II) is also generally soluble, but is limited to relatively low concentrations in sulfuric acid by the solubility of various calcium sulfate compounds. In general, these elements are not of great concern since they are soluble in solution up to a pH greater than about 8 or 9, and therefore they will remain in solution during any subsequent precipitation processes used to recover Ni, Co and / or Mn, and therefore will not contaminate the battery precursor product.

[0214] For the other important impurity elements, the dissolution of iron can be controlled by the oxidation and reduction as well as pH behavior. The dissolution of Sc(III), Ti(IV), V(V), Cr(III), Al(III), Sn(IV), As(III), Sb(III), and to some extent Cu(II), Zn(II), Cd(II) can be controlled by the leaching pH since these elements are fairly soluble at lower pH values ​​and not very soluble at higher pH values ​​in the pH range of about 1-7 or 1-6. Pb(II) is also generally soluble but will be limited by the solubility of lead sulfate compounds in sulfuric acid. Si is generally not very soluble in the pH range of about 1-7 or 1-6.

[0215] Cr, Sn, As and Sb can all be in other oxidation states which affect their solubility. Generally, the higher the oxidation state of these elements, the more soluble they are, and therefore their oxidation or reduction can be controlled to achieve said oxidation states, which in turn will achieve the desired selectivity of Ni / Co / Mn for these elements.

[0216] As stated above, the objective of the process described in one embodiment herein is to obtain Ni, Co and / or Mn in solution with minimal impurities by controlling the oxidation and reduction reactions and the solution pH.

[0217] Subsequent impurity removal steps such as pH adjustment, ion exchange, solvent extraction, precipitation and / or cementation reactions may be performed to further remove and / or separate impurities from the solution. For example, Cu, Zn and Cd may 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 may be separated from the impurities in the leachate by ion exchange or solvent extraction so that they remain together.

[0218] The ratios of the various materials used in the leaching process may be adjusted to target the desired ratio of Ni:Co:Mn in the final leachate.

[0219] Also, additional Ni or Co or Mn may be added to the leachate either before or after the impurity removal step to adjust the Ni:Co:Mn ratio as needed.

[0220] In one embodiment, the end goal may be a solution of sufficient purity with the required Ni:Co:Mn ratio such that a battery cathode precursor can be produced from the solution.

[0221] It should be noted that the term NMC refers to any material containing Ni, Co, Mn that can be used as an active material in a battery.

[0222] Preferred features, embodiments and variations of the present invention can be understood from the following detailed description, which provides sufficient information for those skilled in the art to practice the invention, and is not to be construed as limiting the scope of the preceding summary of the invention in any way.

[0223] Notwithstanding any other forms which may fall within the scope of the invention, preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: [Brief description of the drawings]

[0224] [Figure 1] FIG. 1 shows a flow diagram of a method for producing a coprecipitate comprising nickel, manganese and cobalt obtained from a solid residue according to a method comprising an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a second method for producing a coprecipitate comprising nickel, manganese and cobalt according to a method comprising a second embodiment of the present invention. [Diagram 3] FIG. 3 shows the removal of undesired metals from a cobalt concentrate using an acid pre-wash step, based on filtrate volume. [Figure 4] Figures 4a and 4b show plots of the recovery of various metals into solution compared with pH during leaching of a pre-washed cobalt concentrate under reducing conditions. [Diagram 5] 5a, 5b and 5c show plots of the change in solution phase concentration of various metals during the process of completing the reduction reaction. [Figure 6] Figures 6a-6d show plots of recovery of major elements into solution versus reaction time and pH for 2.5 h treatment of solids at a reactor temperature of 55 °C, 5% initial solids, and 100% stoichiometric loading of SO2. The solids used were: Figure 6a - BMJ-A; Figure 6b - BMJ-B; Figure 6c - BMC; Figure 6d - BMK. [Figure 7] Figures 7a-7d show plots of recovery of major elements to solution versus reaction time and pH for BMK solids treated with various acid additions at a reactor temperature of 55 °C, 5% initial solids, and 100% stoichiometric addition of SO2. Acid was added by: Figure 7a - H2SO4 added stepwise at sampling points to reduce pH to 4.5 and SO2 added over 2.5 hours (31 mL / min); Figure 7b - H2SO4 added continuously to give 100% of the stoichiometric requirement in 200 minutes (1 mL / min) and SO2 added over 2.5 hours (31 mL / min); Figure 7c - H2SO4 added continuously to give 100% of the stoichiometric requirement in 200 minutes (1 mL / min) and SO2 added over 2.5 hours (31 mL / min). 7c-H2SO4 was added continuously to give 100% of the stoichiometric requirement (2.2 mL / min) in 1.5 hours and SO2 was added over 1.5 hours (52 mL / min); Fig. 7d-H2SO4 was delivered at 100% of the stoichiometric requirement at the start of the reaction and SO2 was added over 0.5 hours (220 mL / min). Fig. 7e shows a comparative plot of recovery of major elements to solution versus reaction time and pH, where BMK solids were treated with 5% initial solids and no SO2, at a reactor temperature of 55 °C, and H2SO4 was added continuously to give 100% of the stoichiometric requirement (1 mL / min) in 200 minutes. [Figure 8]Figure 8 shows plots of recovery of major elements into solution versus reaction time and pH, where BMK solids were treated with 20% initial solids and 100% stoichiometric loading (290 mL / min) of SO2 in 1.5 h at a reactor temperature of 55 °C, and 50% H2SO4 was added continuously to obtain 100% of the stoichiometric requirement (2.9 mL / min) in 1.5 h. [Figure 9] Figures 9a and 9b show plots of recovery of major elements into solution versus reaction time and pH, where BMK solids were treated at reactor temperature with 5% initial solids, 100% stoichiometric addition of SO2 (52 mL / min) in 1.5 hours, and continuous addition of H2SO4 to obtain 100% of the stoichiometric requirement (2.2 mL / min) in 1.5 hours. The reactor temperatures were as follows: Figure 9a - 75°C, Figure 9b - 35°C. [Figure 10] FIG. 10 shows a flow diagram of a method of one embodiment of the present invention. [Figure 11] FIG. 11 shows a flow chart of a method of another embodiment of the present invention. [Figure 12] FIG. 12 shows a graph of pH vs. target metal precipitation at 75° C. and 50 ml / min air with pH adjusted by autotitration with 2.5 M NaOH. [Figure 13] FIG. 13 shows a graph of pH vs. impurity element precipitation at 75° C. and 50 ml / min air with pH adjusted by autotitration with 2.5 M NaOH. [Figure 14] FIG. 14 shows a graph of pH vs. target metal precipitation at 75° C. and 50 ml / min air with pH adjusted by autotitration of 200 g / l Na2CO3. [Figure 15] FIG. 15 shows a graph of pH vs. impurity element precipitation at 75° C. and 50 ml / min air with pH adjusted by autotitration of 200 g / l Na2CO3. [Figure 16] FIG. 16 shows a graph of pH versus target metal precipitation at 75° C. with 50 ml / min air and the pH initially adjusted by autotitration of 200 g / l Na2CO3 after addition of solid MnCO3 and BNC. [Figure 17]FIG. 17 shows a graph of pH vs. impurity element precipitation at 75° C. with 50 ml / min air and pH initially adjusted by autotitration of 200 g / l Na2CO3 after addition of solid MnCO3 and BNC. [Figure 18] Figure 18 shows a graph of pH vs. target metal precipitation at 75°C with 50 ml / min air and pH adjusted by autotitration of 200 g / l Na2CO3. Solid-liquid separation occurred at 180 minutes with 150 minutes of base addition. [Figure 19] Figure 19 shows a graph of pH vs. impurity element precipitation at 75°C with 50 ml / min air and pH adjusted by automatic titration of 200 g / l Na2CO3. Solid-liquid separation occurred at 180 min with 150 min of base addition. [Figure 20] FIG. 20 shows the effect of the co-precipitation final pH and initial NMC ratio on the final NMC composition. [Figure 21] Figure 21 shows the extent of Ca2+ and Mg2+ precipitation at different NMC final precipitation pH: initial 50 mg / L Ca+ 200 mg / L Mg in solution; initial 0.12 mol / L Ni, 0.02 mol / L Co, and x mol / L Mn (x=0.02, 0.04, and 0.06) in solution to change the NMC ratio from 6:2:2 to 6:3:2 and 6:4:2. [Figure 22] Figure 22 shows the percent precipitation of Ni2+, Co2+ and Mn2+ at different NMC final precipitation pH. Initial 0.12 mol / L Ni, 0.02 mol / L Co, x mol / L Mn (x=0.02, 0.04, 0.06) in solution for varying NMC ratios from 6:2:2 (solid red dots) to 6:3:2 (red circles), 6:4:2 (red squares). [Figure 23] FIG. 23 shows leaching recoveries from laterite ore samples according to one embodiment of the present invention. [Figure 24] FIG. 24 shows the recovery of solids from NMC precipitation of conditioned laterite ore leachate according to an embodiment of the present invention. [Diagram 25] FIG. 25 shows leach recovery to solution from sulfuric acid leaching of MSP according to an embodiment of the invention. [Figure 26] FIG. 26 shows the recovery of conditioned sulfide concentrate leach solution to solids from NMC precipitates according to an embodiment of the invention. [Figure 27] FIG. 27 illustrates leach recovery to solution from sulfuric acid leaching of mixed cobalt concentrate / black mass according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0225] (Description of the embodiment) Reference will now be made to an exemplary method of the present invention with reference to FIGS.

[0226] A first exemplary method 10 for producing the nickel, manganese and cobalt containing coprecipitate of the present invention is shown in Figure 1. The precipitation method is primarily directed to steps 25 onwards.

[0227] The method may include treating a mixture 15 containing nickel, cobalt and manganese with a reducing agent in an aqueous solution having a pH of about 1-6 (at 20° C.) in which some of the nickel, cobalt and / or manganese are in an oxidized state, and 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.

[0228] The mixture is in particular a wet filter cake obtained from the selective acid leaching (SAL) process disclosed in PCT / AU2012 / 000058 (although cathode material containing nickel, cobalt and manganese from lithium ion batteries may also be used). In general terms, the wet filter cake is obtained by contacting a mixed hydroxide precipitate containing nickel, cobalt and manganese with an acidic solution containing an oxidizing agent at a pH such that nickel dissolves in the acidic solution while cobalt is stabilized in a solid phase, and then subsequently separating the solid phase from the acidic solution, the solid phase comprising at least nickel, cobalt and manganese. In this exemplary embodiment, the solid phase is a wet filter cake.

[0229] In the treatment step with leaching and reducing agents, the wet filter cake may contain cobalt, nickel and / or manganese in oxidized form, i.e. Co(III), Co(IV), Mn(III), Mn(IV), Mn(VII), Ni(III) or Ni(IV). However, this material may also contain significant amounts of unoxidized or reduced cobalt, manganese or nickel, for example in the form of Co(II), Mn(II) or Ni(II). Reduced cobalt, manganese and nickel are much more soluble in aqueous solutions at pH 1-6 than the oxidized forms.

[0230] When the treatment step is carried out, the pH may decrease over time. The preferred pH for carrying out the treatment step is an end pH of about 3-4 (although under more aggressive conditions an end pH of about 2-3 may be suitable), and throughout the treatment step the pH was controlled at this pH through the addition of additional leaching agent or base. The preferred leaching agent is sulfuric acid, but hydrochloric acid, nitric acid, and organic acids may also be suitable. The reducing agent during the treatment step is preferably sulfur dioxide gas, as it is strong enough to reduce cobalt, manganese, and nickel, and thus does not introduce any additional impurities into the aqueous solution. The addition of the reducing agent during the treatment step was controlled to control the reduction of cobalt, nickel, and manganese. The treatment step was carried out in a closed vessel to control gas losses. The reducing agent was added in a controlled manner, with about one stoichiometric equivalent of reducing agent relative to the total moles of cobalt oxide, manganese oxide, and nickel oxide in the mixture. The treatment step was carried out at about 80° C. to about 95° C. with stirring for about 2 hours, or at about 55° C. with stirring for about 1 to 5 hours.

[0231] After process step 20, the aqueous solution, representing the aqueous feed solution of the present invention, contained dissolved nickel, cobalt and manganese, as well as impurities such as arsenic, aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, ammonium, sulfite, fluorine, chloride, titanium, zinc, scandium and zirconium; in particular aluminum, copper, iron (e.g., if starting from black mass derived material) or zinc, calcium, magnesium (also iron and aluminum) (e.g., if starting from MHP derived material). The aqueous solution also contained entrained solids, including impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, zirconium.

[0232] After completion of process step 20, one or more impurities were removed from the aqueous solution containing dissolved nickel, cobalt, and manganese. Solids were removed from the liquid from process step 20 by passing the entrained solids to a settling vessel for decantation / filtration 25. The solids removed from the settling vessel were returned to process step 20. The liquid removed from the settling vessel was further processed to remove impurities at 35. Exemplary impurities removed from the liquid may include iron, copper, zinc, aluminum, which may be accomplished using precipitation and / or ion exchange separation techniques. Ion exchange may, for example, assist in the removal of at least some of the zinc.

[0233] After removal and / or separation of impurities, nickel, cobalt and / or manganese are co-precipitated from the aqueous solution at 40. However, prior to co-precipitation, additional cobalt, nickel, manganese may be added to adjust the ratio of nickel, cobalt and manganese to a desired ratio or to provide a desired ratio in the coprecipitate. An exemplary 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 cobalt, manganese and nickel containing compounds.

[0234] The co-precipitation step at 40 can also be performed by adjusting the pH of the solution containing the dissolved nickel, cobalt and manganese, preferably by adjusting the pH of the solution to about 7.5 to about 8.6. This pH range has been found to result in less co-precipitation or incorporation of unwanted impurities such as, for example, magnesium and / or calcium salts, than when higher pH ranges are used. The step was performed at 80°C and ambient pressure. Nickel, cobalt and manganese were co-precipitated in the hydroxide form. A two-step resuspension wash using 0.5% NH3 solution may be used.

[0235] The precipitate was then separated from the liquid, for example via decanting or filtration at 45. Advantageously, further impurities were removed via a co-precipitation process, as some impurities such as sodium, potassium, magnesium, calcium, sulfates remained in solution. The liquid was further processed (e.g., precipitation or ion exchange) for nickel, manganese or cobalt recovery at 55, and the solid was washed to remove further impurities, mixed with lithium and calcined at 50. This calcined product may be used as NMC material for use as a cathode active material (CAM) in new batteries.

[0236] A similar process 110 is shown in Figure 2. Like numbers refer to like features. However, the process shown in Figure 2 includes an optional pre-wash. This can be a wash with a weak acid leach solution at a starting pH of about 3.5 (with the pH increasing as the wash progresses), resulting in a solution containing about 10% solids. Such a pre-wash can remove at least zinc, magnesium, and calcium.

[0237] In contrast to that shown in FIG. 1, the method shown in FIG. 2 also uses a counter-current setup, as will be further described below. In FIG. 2, two mixing vessels 120a, 120b and two settling vessels 125a, 125b are used. As shown in FIG. 2, a mixture containing nickel, cobalt and manganese is added to an aqueous solution in a first mixing vessel 120a, which is being stirred. The solution (including entrained solids) leaves the first settling vessel 120a via a first settling vessel liquid outlet and enters the first settling vessel 125a via a first settling vessel liquid inlet. The first settling vessel 125a may include at least an upper outlet at the top of the vessel to provide an outlet for the liquid and a lower outlet at the bottom of the vessel to provide an outlet for the settled solids. The liquid leaving the first settling vessel via the upper outlet proceeds to a step of separating the liquid impurities in the solution at 135. The liquid / solids leaving the first settling vessel 125a via the bottom outlet flow into the second mixing vessel 120b via the second mixing vessel inlet. A reducing agent 105 and a leaching agent 108 have been added to the second mixing vessel 120b which is being stirred. The solution (including entrained solids) leaves the second mixing vessel 120b via the second mixing vessel liquid outlet and enters the second settling vessel 125b via the second settling vessel liquid inlet. The second settling vessel 125b includes at least an upper outlet at the top of the vessel to provide an outlet for the liquid and a lower outlet at the bottom of the vessel to provide an outlet for the settled solids. The liquid leaving the second settling vessel via the top outlet flows into the inlet of the first mixing vessel 120a. The liquid / solids leaving the second settling vessel via the bottom outlet are disposed of at 130, for example after passing through a screw press. The advantage of this arrangement is that it minimizes the amount of acid and reducing agent remaining in the solution that the nickel, cobalt and manganese co-precipitated in. Additionally, the amount of iron in the first settling vessel was minimized by maintaining precise conditions.

[0238] 1, the mixture of 115 is a wet filter cake obtained from the selective acid leaching (SAL) process disclosed in PCT / AU2012 / 000058, among others (although cathode material containing nickel, cobalt and manganese from lithium ion batteries may also be used). The SAL process is mentioned above, as are the oxidation states of cobalt, manganese and nickel.

[0239] Again, the preferred pH for carrying out the treatment process was a pH of about 3, and throughout the treatment process in the mixing vessels 120a, 120b and settling vessels 125a, 125b, the pH was controlled at this pH through the addition of additional leaching agent or base. The preferred leaching agent is sulfuric acid, but hydrochloric and nitric acids may also be suitable. The reducing agent in the treatment process is preferably sulfur dioxide, as it is strong enough to reduce the cobalt, manganese, nickel, and does not introduce any additional impurities into the aqueous solution. The addition of reducing agent in the treatment process was controlled to control the reduction of cobalt, nickel, and / or manganese, and to optimize utilization of the reducing agent. The treatment process was carried out in a closed vessel to control gas losses (which would need to be vented and scrubbed of off-gases). The reducing agent was added in a controlled manner, with about one stoichiometric equivalent of reducing agent to the total moles of cobalt oxide, manganese oxide, and nickel oxide. The treatment process was carried out at a temperature of about 55° C. with stirring for about 1 to 5 hours.

[0240] After process steps 120a, 120b, the aqueous solution contained 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 contained entrained solids including impurities such as aluminum, barium, cadmium, carbon, chromium, copper, lead, silicon, fluorine, titanium, zinc, and zirconium.

[0241] The liquid removed from the first settling vessel 125a was further processed to remove impurities at 135. Exemplary impurities removed from the liquid may include iron, copper, zinc and aluminum, which may be accomplished using precipitation and / or ion exchange separation techniques.

[0242] After removal and / or separation of impurities, the nickel, cobalt and manganese were co-precipitated from the aqueous solution at 140. However, prior to co-precipitation, additional cobalt, nickel and / or manganese may be added to adjust the ratio of nickel, cobalt and manganese to the desired ratio, as described above for Figure 1. The co-precipitation step at 140 was as described above for Figure 1.

[0243] The precipitate was then separated from the liquid via decantation or filtration. The liquid was further processed (e.g., by precipitation or ion exchange) for nickel, manganese or cobalt recovery at 155, and the solid was washed to remove further impurities and then mixed with lithium and calcined at 150. This calcined product may be used to provide NMC material for use as a cathode active material (CAM) in advanced batteries.

[0244] In further embodiments, the methods outlined in Figure 10 or Figure 11 may be used in the methods outlined in Figures 1 and 2 prior to the impurity separation / co-precipitation step. In these methods, the oxidized nickel, cobalt, manganese material 201 (Figure 10) or reduced nickel, cobalt, manganese material 251 (Figure 11) is treated with acid 203 / 253 to a pH of about 1 to about 6 or about 1 to about 7, optionally water 205 / 255, and an oxidizing agent (207) or reducing agent (257) (depending on the starting material). The resulting solution may be leached in leach vessel 210 / 260, after which the leachate may be filtered 215 / 265 to remove impurity solids 218 / 268. The leachate is then sent to a processing vessel 220 / 270 (note: leaching vessel 210 / 260 can be the same as processing vessel 220 / 270) where an oxidizing agent 222 (if starting with oxidized NMC material 201) or a reducing agent 272 (if starting with reduced NMC material 251) is added to neutralize excess reducing agent 207 or oxidizing agent 257 remaining in the leachate. A base 224 / 274 may also be added to increase the pH (e.g., the solution in the leaching vessel may have a pH of about 3 and the solution in the processing vessel may have a pH of about 6). Thus, some material may precipitate in the processing vessel 220 / 270, which may then be filtered 230 / 280 to provide impurity solids 232 / 282 and NMC solution 234 / 284.

[0245] Exemplary results of the method are provided below.

[0246] leaching Example 1: MHP-derived starting materials Acid pre-cleaning

[0247] In this experiment, a cobalt concentrate originating from a pilot plant (Brisbane Metallurgy Laboratories) was used. The cobalt concentrate had the following elemental composition based on total dissolution and solution assays: 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 from a SAL process utilizing mixed hydroxide precipitation (MHP - solid nickel-cobalt mixed hydroxide precipitation). MHP is contacted with an acidic solution containing an oxidizing agent at a pH such that cobalt is stabilized in the solid phase and nickel dissolves in the acidic solution, and then the solid phase is separated from the acidic solution, and the solid phase may contain nickel, cobalt, and manganese.

[0248] The cobalt concentrate was washed with a weak acid to reduce the impurity content associated with the entrained solution and residual nickel hydroxide. Due to the high solution retention of solids in the filtration, a combination of reslurry washing and displacement washing using a pressure filter was used in this example.

[0249] In this process, the cobalt concentrate (180 g dry solids) was first mixed with 5 g / L H2SO4 at room temperature to produce a slurry containing 20 wt% solids. The slurry was then washed into a pressure filter, (i) filtration was stopped after approximately 200 mL of solution had been collected, and then (ii) the filter was depressurized, 200 mL of 1 g / L H2SO4 was added to the filter, and filtration was resumed. Steps (i) and (ii) were repeated until a total of 1 L of 1 g / L H2SO4 had been added to the filter. The remaining solution was filtered and collected in batches of approximately 200 mL. After the last solution was collected, air was blown through the filter for 30 minutes.

[0250] As shown in Tables 1 and 2 and Figure 3, the process was effective in reducing the Ca (93%) and Mg (93%) content of the leached solids, and was moderately effective for Ni and Zn (60%). There was negligible loss of Co and Mn to solution (<10 mg loss out of 180 g dry solids). Fe and minimal Cu were not washed away. The final 500 mL of the 1 L acid wash solution contained almost no dissolved metals.

[0251] [Table 3]

[0252] [Table 4]

[0253] Treatment with reducing agents and acids The washed cobalt concentrate was slurried at 5 wt%, heated, and SO2 was bubbled through the reactor to reduce solids at pH 4 as the experimental endpoint. This endpoint was chosen because it had shown good recoveries in previous tests with some selectivity for impurity elements. Due to a calculation error, the initial SO2 flow rate was too low and had to be increased to complete the experiment.

[0254] In this process, the washed cobalt concentrate was first slurried at 5% solids in deionized water and heated to 55° C. Next, 12 mL / min of SO2 was bubbled through the slurry for 5 hours. The flow rate of SO2 was then increased to 36 mL / min for an additional 110 minutes until the solution achieved a pH of 4. Finally, the slurry was filtered to recover the solution (filtrate).

[0255] As shown in Table 3 and Figures 4a-b, treatment with reducing agent and acid recovered >90% of the target metals (Ni, Mn, and Co). Gradual addition of SO2 allowed the target metals to be eluted with selectivity towards Al, Cu, and Fe until near the end point. Ca and Mg eluted faster than the target elements, but the final solution concentrations were low (<30 mg / L) due to effective acid washing of the feed solids.

[0256] TIFF2024508529000006.tif62167

[0257] Without wishing to be bound by theory, the inventors believe that initially, the acid-forming reaction between SO2 and water occurs as a result of the Co 3+ and Mn 4+ We believe that this is overwhelmed by the reduction of hydroxides, leading to an increase in pH. Once the bulk of the reduction is nearly complete, the pH drops until buffered by the dissolution of divalent hydroxides around pH 5, and then drops further as recovery to solution approaches a maximum.

[0258] End of reduction The filtrate from the previous section was contacted with acid washed cobalt concentrate (as an oxidant) at 80°C to consume any SO2 remaining dissolved in solution and precipitate the iron. MnCO3 was added to increase the pH and aid in impurity precipitation while offsetting the expected loss of Mn in the ion exchange (IX), but the pH remained stable (at about pH 4.8) due to a buffering effect resulting from the impurity precipitation reaction.

[0259] In this process, the filtrate was first slurried with 5% solids washed cobalt concentrate (50 g) and heated to 80° C. After 1 hour, 13.8 g of MnCO3 was added to the slurry, and after 8 hours the slurry was filtered. The pH of this process ranged from 5.1 to 4.6.

[0260] As shown in Table 4 and Figures 5a, 5b and 5c, contacting the MnCO3-spiked leachate with the unleached solid at 80°C resulted in rapid (within minutes of contact with the solid) removal of Al, Cu and Fe. The concentrations of Ni and Co remained relatively stable, while Mn precipitated (or precipitated) first and gradually increased after addition of MnCO3.

[0261] [Table 5]

[0262] In previous oxidation tests without added MnCO3, the Co, Ni and Zn concentrations in solution all increased, while the final Mn concentration was very low (without subsequent dissolution, similar to the precipitation seen in this experiment). The pH remained relatively stable despite the addition of MnCO3 (5.04 immediately after addition of the solid, and 4.67-4.87 for the remainder of the tests).

[0263] Ion Exchange (IX) The filtrate from the previous paragraph was contacted with Lewatit® VP OC 1026 macroporous ion exchange resin (based on styrene divinyl benzene copolymer containing di-2-ethylhexyl phosphate (D2EHPA); this 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 using 0.1M H2SO4 and 1M NaOH before contact with IX, with a target pH of 3.8-3.9. The resin was acid washed with 10% H2SO4 and then adjusted to pH 3.5 before use. The additions in the following paragraphs are given in terms of the amount of resin as received, taking into account the mass changes during washing. 1. 250 mL of the filtrate was added to a bottle and the pH was controlled at 3.9. 2.120 mL of resin was added, the bottle was sealed and placed on a bottle roller at 40° C. for 24 hours. 3. The resin was filtered off and the solution was added to a clean bottle. 4. The pH was adjusted to 3.8. 5.120 mL of resin was added, the bottle was sealed and placed on a bottle roller at 40° C. for 4 hours. 6. The resin was removed by filtration and the solution was recovered.

[0264] Based on previous ion exchange (IX) testing, two sequential contacts at 40°C with minimal pH control were selected to maximize Zn removal and minimize Mn loss. Tables 5 and 6 show the results of the solution assays before and after each contact. The dilution corrected assay takes into account the solution retained on the resin from washing and conditioning. Both contacts showed superior Zn removal (87% and 91%) compared to previous testing, but Mn loss was not completely mitigated (15% and 16%). Some Al and Ca were also removed (cumulatively 29% and 32%, respectively), and Fe was <1 mg / L by IX.

[0265] [Table 6]

[0266] [Table 7]

[0267] Example 2: Starting material from a lithium-ion battery (black chunks) Materials and equipment The reagents used in this work were food grade SO2 and reagent grade 98% H2SO4. The composition of the black chunk samples used is provided in Table 7. These samples were obtained from lithium ion batteries that were crushed and subjected to chemical cleaning.

[0268] [Table 8]

[0269] All reactions were completed in a 1.1 L baffled glass reactor. Temperature was maintained with a hotplate with thermocouple feedback control. Agitation was achieved with an overhead stirrer set at 800 RPM using a high shear Teflon impeller. Gas was sparged using a glass sparging rod connected to a gas flow meter to control the rate of gas addition. To ensure maximum gas dispersion during the reaction, care was taken to ensure that the sparger was submerged to a constant level in line with the impeller blades.

[0270] method The required amount of black mass was weighed directly into the reactor initially. The required amount of water was then added and the reactor was heated to reaction temperature. Once at reaction temperature, the first sample was taken via pipette and cooled to room temperature in a sealed syringe. After cooling, the sample was filtered through a syringe filter, diluted with nitric acid and excess sample was returned to the reactor. If necessary, hoses from the SO2 sparge and acid pump were inserted into the reactor and timing was started. Samples were taken at predetermined time intervals depending on the experiment following the sample method as outlined for the initial sample.

[0271] Once the reaction time had elapsed, the reactor was weighed for mass balance purposes and the slurry was vacuum filtered. The wet solids were then dried overnight at 105° C. and the solution was stored in a glass bottle.

[0272] The rates of SO2 and H2SO4 addition were calculated based on the flow rates required to administer 100% of the stoichiometric dose and react all Li, Ni, Mn, and Co to their divalent states in the required time, assuming that Ni and Co all exist in their trivalent state and Mn in its tetravalent state.

[0273] Results – Effect of sample type Four black masses were treated using only SO2 gas as the reductant at 55°C without the addition of further acid. This condition was chosen as an initial baseline as it provided a comparison point for previously completed reduction leaching tests carried out on cobalt concentrates. All tests were carried out at a solids concentration of 5%. 5% solids was chosen to conserve sample mass and to aim for a total metal concentration of approximately 0.2M in the final solution. A metal concentration of 0.2M was chosen as the target for the subsequent NMC precipitation operation. Full experimental details of the tests carried out are provided in Table 8.

[0274] [Table 9]

[0275] The elution range and pH profile as a function of time for the tests summarized in Table 7 are shown in Figures 6a-6d. Comparing these results, it is clear that BMJ-B outperforms the other test samples. BMJ-B is highly amorphous, which would result in a much higher reactivity compared to the more crystalline samples. We believe this is likely due to the removal of lithium from the sample. The material was delithiated, which destroys the crystal structure and renders the sample amorphous. Thus, resulting in the requisite faster kinetics, with over 90% of the cobalt being recovered in 5 hours. The Canadian sample (BMC) contained the most impurities and was the least pretreated of all the samples. BMC performed similarly in cobalt recovery, but was only able to achieve 75% recovery of nickel. We believe the improved performance of this sample is due to the higher concentration of metal impurities (Al, Cu, Fe metals) which act as reducing agents and improve recovery. Both the BMJ-A and Korean samples (BMK) were pure and highly crystalline samples, and both achieved only 50% recovery of Ni, Co, and Mn at 5 hours. Because of this, BMK was selected as the representative sample for all further testing, as it had sufficient sample mass and was comparable to the most difficult samples to leach. If this material is leachable, then all black mass samples should be leachable under similar conditions, and so the most difficult was selected.

[0276] Results – Effect of reagent dosing rate Five experiments were performed to study the effect of reagent addition rate. All samples used BMK solids at 55°C and 5% solids concentration. SO2 and acid (20% H2SO4) were added to the reactor according to Table 9. For the continuous acid test, acid was added by a peristaltic pump.

[0277] [Table 10]

[0278] Solution recoveries for the tests summarized in Table 9 are shown in Figures 7a-7d. Comparing Figures 7a-7d to Figure 6d, the addition of either volume of H2SO4 resulted in significantly improved recoveries and kinetics.

[0279] Stepwise addition of acid at 100% stoichiometric SO2 for 2.5 hours (Figure 7a) resulted in an improvement in recovery from 50% at 5 hours to over 80% at 5 hours. For this experiment, 6 hours was included, after which a large amount of acid was added to bring the pH below 3. Thus, there was an immediate spike (5%) in both Co and Ni recoveries. In this final hour, recoveries increased to 90% for all target metals, indicating that the system was still acid limited.

[0280] In the slow continuous acid test (Figure 7b), acid was delivered by a peristaltic pump to deliver 100% of the stoichiometric acid demand in 200 minutes and 100% stoichiometric SO2 in 2.5 hours. This test resulted in greater than 90% recovery of the target metal in 180 minutes. The recovery did not change appreciably after this time point indicating a terminated reaction. It should be noted that this recovery value is based on a solution assay and that analysis of the solids actually showed that the recovery in this test was greater than 98%. Therefore, the elution range in the graph is biased low since the head calculated from the final solution and final solid assays should be more accurate.

[0281] In the fast run (Figure 7c), both the acid flow rate and SO2 addition rate were increased to provide 100% of the stoichiometric requirement at 90 minutes. Under these conditions, it was found that approximately 100% of all target metals were extracted at 90 minutes. After this time (or point), there was little change in the recovery of the target metals, but impurity elements continued to be recovered. At 90 minutes, 40% of aluminum and 10% of iron were recovered in solution, increasing to 60% and 15%, respectively, after 2.5 hours. This indicates that there is no benefit in further increasing the reaction time beyond the time required to obtain 100% of the reagents. Comparing the impurity recoveries in this run (Figure 7c) to the slow acid run (Figure 7b) revealed that there was some improvement in selectivity at the slower addition rate. Maximum recovery was achieved at 150 minutes at the slow rate. At this point, only 10% Al and 2% Fe were recovered. Comparing this with the fast addition at 90 minutes shows approximately a six-fold increase in impurity recovery.

[0282] Figure 7d shows the results of the immediate acid test. In this experiment, 100% of the stoichiometric acid demand was added at the start of the experiment, and stoichiometric addition of SO2 was achieved in 30 minutes. Just the full acid addition was sufficient to recover 35-40% of Ni, Mn, and Co, and 90% of Li. These recoveries increased to over 90% for all metals within 30 minutes. After 30 minutes, all target metals slowly declined to 85-90% recovery over the 2.5 hour reaction time. There was a steep drop in nickel at 60 minutes, which is believed to be an outlier caused by an error in dilution. Aluminum was quickly recovered to 60% after acid addition, and this value slowly increased over time to a maximum of 78%. Iron recovery was consistent at 10-11% after acid withdrawal. This shows approximately the same selectivity as the fast continuous acid test, but the kinetics were significantly increased.

[0283] A final test (reference example) was performed without SO2 and with acid only (Figure 7e). After 5 h, only 30-40% of Ni, Mn and Co were recovered, while Li was 80% recovered. These results are consistent with the recoveries achieved in the immediate acid test before adding SO2. This indicates that for the BMK sample, without any reducing agent, about 40% of Ni, Mn and Co are soluble.

[0284] Results – Effect of solids concentration One experiment was conducted to examine the effect of higher solids concentration on the extent and kinetics of the reaction as the temperature rises. A higher solids concentration was chosen to be examined as it would result in a more concentrated leachate. This would increase the efficiency of downstream impurity separation as well as reduce the required reactor volume given a set throughput. In this test, BMK solids were reacted at 55°C at 20% solids concentration. Acid was added continuously under conditions equivalent to the fast continuous acid test (2.9 ml / min 50% H2SO4, 290 ml / min SO2). In this experiment, 50% H2SO4 was used to prevent overflow from the reactor. This higher acid strength caused excessive heating of the solution, increasing the temperature to approximately 75°C in the first half hour. After this, the reactor was transferred to a cooling water bath and the temperature was held constant at approximately 45°C. Therefore, the effects of solids concentration and temperature could not be completely deconvoluted, which must be kept in mind when interpreting the results.

[0285] Figure 8 shows the results of an experiment carried out under fast sequential reagent conditions at 20% solids. Thus, overall recovery and reaction rate were reduced compared to an equivalent test at 5% solids, with 80% recovery achieved after 2 hours. However, when the experiment had to be terminated, recovery tended to increase, and thus complete dissolution at 20% solids is expected to be possible.

[0286] Results – Effect of reaction temperature Two experiments were performed to investigate the effect of temperature on the extent and rate of reaction. Higher temperatures were investigated in an attempt to further improve the reaction rate by increasing the rate of dissolution. BMK solids were reacted at 75°C at a solid concentration of 5%. Acid was added continuously under conditions equivalent to the fast continuous acid test (2.2 ml / min 20% H2SO4, 52 ml / min SO2). It should be noted that values ​​above 100% are displayed in Figure 9a, but are likely due to evaporation. Due to errors in recording the mass throughout the experiment, an estimate of mass loss due to evaporation was not possible.

[0287] Lower temperatures were investigated in an attempt to further improve the reaction rate by increasing the solubility of SO2 gas in solution. The BMK solids were reacted at room temperature at 5% solids concentration. Over the course of the experiment the temperature rose naturally to 30°C-35°C. The acid was added continuously under conditions equivalent to the fast continuous acid test (2.2 ml / min 20% H2SO4, 52 ml / min SO2). It should be noted that values ​​above 100% are displayed in Figure 9b, but are likely due to evaporation. Due to errors in recording the mass throughout the experiment, an estimate of mass loss due to evaporation was not possible.

[0288] As can be seen in Figure 9a, increasing the reaction temperature resulted in a decrease in performance compared to the equivalent test at 55°C. At 75°C, recovery, selectivity, and kinetics were all adversely affected by increasing the reaction temperature. The inventors believe this is due to slower reduction of metals as a result of decreased solubility of SO2. Similarly, decreasing the reaction temperature also had a detrimental effect on recovery and kinetics. At 35°C, reaction times of 120-150 minutes were required to achieve greater than 90% recovery for all target metals.

[0289] Precipitation Removal of impurities by ion exchange (IX)

[0290] A feed solution of the composition shown below was contacted with Lewatit® VP OC 1026 macroporous ion exchange resin (based on styrene divinyl benzene copolymer with di-2-ethylhexyl phosphate (D2EHPA)).

[0291] [Table 11]

[0292] Contact with the ion exchange resin was carried out in two stages at 40°C. pH control was performed using 0.1M H2SO4 and 1M NaOH before IX contact with a target pH of 3.8-3.9. The resin was acid washed with 10% H2SO4 and adjusted to pH 3.5 before use. Additions in the following paragraphs are given in terms of the amount of resin as received to account for mass changes during washing. 7. 250 mL of the filtrate was added to the bottle and the pH was controlled at 3.9. 8.120 mL of resin was added, the bottle was sealed and placed on a bottle roller at 40°C for 24 hours. 9. The resin was filtered and the solution was added to a clean bottle. 10. The pH was adjusted to 3.8. 11.120 mL of resin was added, the bottle was sealed and placed on a bottle roller at 40°C for 4 hours. 12. The resin was removed by filtration and the solution was recovered.

[0293] Based on previous ion exchange (IX) testing, two contacts in series at 40°C with minimal pH control were selected to maximize Zn removal and minimize Mn loss. Tables 10 and 11 show the results of the solution assays before and after each contact. The dilution correction assay takes into account the solution retained on the resin by washing and conditioning. Both contacts showed superior Zn removal (87% and 91%) compared to previous testing, but Mn loss was not completely mitigated (15% and 16%). Some Al and Ca were also removed (cumulatively 29% and 32%, respectively), and Fe entered IX at less than 1 mg / L.

[0294] [Table 12]

[0295] [Table 13]

[0296] Removal of impurities from the feed solution This experiment summarizes the investigation into impurity removal from synthetic solutions. Synthetic solutions were used to ensure reproducibility and sufficient sample numbers. The solutions were created to mimic the solution concentrations and pH generated during leaching. The main parameters investigated in this report are pH and base type.

[0297] It was shown that by increasing the pH to 6.2, 100% of the aluminum, copper, chromium, iron and zinc impurities could be removed from the solution. It was found that at pH 5-5.5, all of the aluminum, chromium and iron, as well as most of the copper, had been removed. Zinc did not precipitate appreciably until pH 6, at which point 95% of the zinc and all of the remaining copper were lost. Increasing the pH to 6.2 removed the remaining zinc and produced a solution free of impurities (except Ca and Mg). A pH of 6.2 was required to reach the calculated solution specifications. Increasing the pH to 6.2 resulted in the loss of approximately 25% Ni, 15% Co and 10% Mn.

[0298] Three different base types were tried. Sodium hydroxide and sodium carbonate produced nearly identical results. All impurities precipitated at the same pH and the loss of target metal was consistent with both bases. However, the use of sodium carbonate resulted in significantly better properties of the resulting solid. The use of a combination of manganese carbonate and basic nickel carbonate produced similar results to sodium carbonate; however, the manganese carbonate did not completely dissolve, resulting in wasted manganese. For this reason, it is recommended to use sodium carbonate as the base for impurity removal.

[0299] There was a clear opportunity to perform impurity removal in two stages. First, at pH 5.5, the majority of the impurities in the solution could be removed. The solids could be separated from the solution and disposed of as waste. The good filtration properties of the carbonate solids allow for quick and easy separation of the solids. After this stage, the partially purified solution would contain only traces of copper and zinc as impurities. An increase in pH to above 6 (ideally 6.2) would allow the remaining copper and zinc to be removed from the solution. This would result in the loss of the nickel, cobalt and manganese, and this solids stream would be of high value. This material could be recovered and returned to the SAL leachate, recovering the copper and removing the zinc impurity from the system. This concept was demonstrated on a laboratory scale by including a solid / liquid separation between the two desired pH levels (5.5 and 6.2). It was found that the inclusion of a solid / liquid separation limited the losses of cobalt, nickel and manganese to 5%, 10% and 0%, respectively.

[0300] The results presented here highlight the feasibility of removing ion exchange from the process. The experimental results show that it is possible to produce high purity solutions by precipitation alone, without the need for expensive ion exchange processes.

[0301] Introduction Based on the known pH dependence on the solubility of metal hydroxides, it was thought possible to selectively remove the hydroxides from solution. The impurities considered were iron, aluminum, copper and calcium. However, assays of black mass samples showed that they may contain magnesium and zinc. The parameters tested in this study were pH and type of base.

[0302] material and method material All reagents used in this study were reagent grade, except for SO2, which was food grade. The chemicals used and their target concentrations in stock solutions are listed in Table 12.

[0303] [Table 14]

[0304] The solution concentrations were chosen to be representative of solutions produced via leaching of black mass. Impurity elements were dosed to simulate the higher expected impurity concentrations. The pH was initially lowered to a target value of 1. This was exceeded (or overshot) to a pH of approximately 0.5. However, this starting pH was too low, which created volumetric problems during precipitation tests. To combat this, the pH was increased to 2.6 using NaOH. SO2 was then sparged into the reactor until the solution was saturated to more closely mimic the solution produced during leaching. The pH was then increased again to 2.6.

[0305] Device All reactions were completed in a 1.1 L baffled glass reactor. Temperature was maintained by a hot plate with thermocouple feed back control. Agitation was achieved with an overhead stirrer set at 800 revolutions per minute with a high shear Teflon impeller. Gas was sparged using a glass sparging rod connected to a gas flow meter to control the gas addition rate. Care was taken to ensure maximum gas dispersion during the reaction by ensuring that the sparger was submerged to a constant level in line with the impeller blades. pH was controlled using a Methrohm autotitrator connected to a high temperature pH probe and a PID program run via a connected laptop.

[0306] methodology The required amount of stock synthesis solution was first weighed directly into the reactor and the reactor was heated to the reaction temperature. After the reaction temperature, the first sample was taken and cooled to room temperature in a sealed syringe. After cooling, the sample was filtered through a syringe filter and diluted with nitric acid, and the excess sample was poured back into the reactor. The air sparge and hoses from the titrator were then inserted into the reactor and the reagent injection and timing were started. Samples were taken at time intervals pre-determined by the experiment following the same sampling method.

[0307] After the experiment was completed, the reactor was weighed and the slurry was centrifuged for the hydroxide samples or vacuum filtered for the carbonate samples. The wet solid was then dried overnight at 105 °C and the solution was stored in a glass bottle. Density measurements were taken before and after the reaction.

[0308] To determine if the experiment achieved the required solution purity, a series of solution target concentrations were calculated. These targets are shown in Table 13 and were calculated assuming 100% transfer to the final precipitated NMC product.

[0309] [Table 15]

[0310] result Effect of pH Test conditions and justification pH is an important parameter that determines the efficiency of separation of impurity elements from the target metal. To study the effect of pH, an automatic titrator was used to dose base (2.5M NaOH) to the stock solution to maintain the solution at the target pH. After reaching this target pH, the pH was held for 1 hour before a sample was taken. After the second sample, the pH controller was adjusted to the next level and the process was repeated. The temperature was kept constant at 75°C throughout each experiment. Three experiments were performed in this manner, with the most conclusive test results presented in this report and others referenced at specific points.

[0311] Results and Discussion From visual observations and trends in base dosage and pH, initial precipitation began to occur at pH 3.6-4. After the solution was held at pH 4 for 1 hour, over 90% of the Fe and almost all of the Al and Cr had been removed from solution. Further increase in pH to 5 resulted in complete removal of Fe, Al, and Cr, and 65% of the Cu impurity. To completely remove Cu, the solution needed to be raised to pH 6, at which point 94% of the Zn had also been removed. To meet the zinc solution specification outline in Table 11, the pH needed to be raised to 6.2. However, at pH 6.2, 11% of the cobalt, 21% of the nickel, and 7% of the manganese were lost. Increasing the pH beyond this point resulted in losses of over 90% of the nickel, 80% of the cobalt, and 40% of the manganese. The major pH buffering was found to occur near pH 6.4. This therefore represents an upper limit that should never be exceeded to reduce losses of the target metals.

[0312] In addition, it was found that rapid base addition to pH 5 resulted in increased nickel losses at lower pH. Fast base addition caused 15% of the nickel to co-precipitate with impurity elements. Therefore, a slow pH increase to pH 5.5 over a period of 2 hours is recommended. This should be held for 1 hour to maximize copper precipitation. The solution is then raised to pH 6.2 and immediately separated from the solution. This is based on the observation that zinc and copper specifications are met at this point and further hold at pH 6.2 will only result in increased nickel, cobalt and manganese losses.

[0313] Effect of base type Test conditions and justification Using methods similar to those described in the previous section, two further tests were conducted to explore alternative bases. Sodium carbonate is an ideal candidate to replace NaOH as the base used for impurity removal, as it is equally available but typically less expensive to source. Additionally, carbonate anions may allow for further impurity removal advantages compared to hydroxides.

[0314] The second alternative base investigated was a combination of sodium carbonate with solid manganese carbonate and basic nickel carbonate (BNC). These chemicals are inexpensive and may be available on-site, thus presenting a mechanism for reducing reagent costs. In this test, manganese carbonate and BNC were added as solids so that the Ni:Mn:Co ratio of the final solution after impurity removal was 6:4:2, reflecting ongoing developments in NMC precipitation. This represents the theoretical maximum amount that these compounds should be added, as it would require dosing of expensive cobalt salts. The metal salts were added at time 0 and allowed to react for 1 hour. After this point, sodium carbonate was added to further adjust the pH as in other experiments.

[0315] Results and Discussion Comparing the results shown in Figures 14 and 15 with those of NaOH shows that there is no significant difference between the two bases. Table 14 shows a comparison of the main considerations of both bases. It shows that when Na2CO3 was used, impurity elements were removed at the same stage compared to NaOH. The amount of target metal lost after precipitation was also consistent. Therefore, it can be concluded that precipitation is occurring as a result of the pH increase and that the carbonate anion does not improve the precipitation. However, it is important to note that Na2CO3 has a strong advantage in material handling. The solids produced during carbonate precipitation are easier to settle and filter than those produced in hydroxide precipitation.

[0316] [Table 16]

[0317] The addition of MnCO3 and BNC yielded no advantage compared to testing Na2CO3 alone (see Figures 16 and 17). Impurity removal was achieved to the same level at the same pH. However, it should be noted that MnCO3 did not completely dissolve indicating its limited ability to act as a base in this situation. Dissolving BNC resulted in greater than 100% nickel recovery, indicating that the assumption that BNC exists as a tetrahydrate was incorrect. All of the BNC dissolved and could theoretically be used as a base if the molar ratio allowed for additional nickel to be added to the system prior to precipitation of NMC.

[0318] Effect of two-stage precipitation Based on the results of the Na2CO3 and NaOH precipitation experiments, it appears that an opportunity exists to split this unit into two operations at two pH levels. By initially precipitating at pH 5.5, all of the Al, Cr and Fe could be removed along with approximately 90% and 10% of the Cu and Zn, respectively. This could be achieved with minimal loss of target metals. Following this, solid-liquid separation could be used to remove the unwanted low value waste. The solution could then be raised to pH 6.2 to remove the remaining Cu and Zn. This was accompanied by approximately a 30% loss of Ni, a 20% loss of Co and a 10% loss of Mn. This material was of high value and could be recovered and recycled to an earlier stage in the process.

[0319] To test this concept, an experiment was conducted using a 200g / l Na2CO3 solution where the pH was slowly increased to 5.5 over approximately 1.5 hours. This pH was held for 1 hour before vacuum filtration. The clarified solution was then reheated and base dosing resumed to give a pH of 6.2. This was held for 1 hour before the final solid / liquid separation.

[0320] Results and Discussion In contrast 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. This observation was supported by the results shown in Figures 18 and 19. It is clear from these results that the inclusion of solid-liquid separation resulted in significantly better retention of Ni, Co and Mn without compromising the removal of impurities. The results of this test for the Na2CO3 single stage test are shown in Table 15.

[0321] [Table 17]

[0322] Co-precipitate formation The objective of this experiment is to explore NMC precipitation-impurity precipitation as a function of pH testing. The objective is to identify the appropriate pH range and solution conditions that can precipitate the NMC precursor to achieve the appropriate major element chemistry (Ni / Co / Mn) while being selective for the impurities Ca and Mg. In the slightly alkaline pH range (pH 7.6-8.0), the majority of the impurity ions (Ca 2+ and Mg 2+ ) was found not to co-precipitate with the NMC precursor. This result suggests that this approach is feasible for the preparation of NMC precursors by adjusting the initial NMC composition, alkali type and amount in the solution.

[0323] Experimental 500 mL of NMC initial solution (0.2–0.24 M total NMC, see Figure 20 for specific samples) was pumped at a rate of 8 mL / min into a 1 L reactor containing 200 mL of ammonium solution (0.1 M). After 3 min, 480 mL of alkali solution (0.20–0.24 M) was pumped into the same reactor at the same flow rate. After 60 min, all remaining liquid was pumped into the reactor. The reactor was heated to 80 °C using a hot plate under an inert gas (N2) atmosphere. During the pumping of the transition metal and alkali solutions (1 h), the mixture was vigorously mixed in the 1 L reactor using an overhead mechanical stirrer at 800 rpm. The stirring speed was then kept at 800 rpm for 4 h until 5 p.m. For safety reasons, the stirring speed was set at 600 rpm for 15–16 h during the following hours. The total precipitation time ranged from 20–21 h. 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. In the first washing, the precipitate was reprecipitated in 0.1M NaOH solution (solid content about 5%) with magnetic stirring at 80°C for 60 min, followed by solid-liquid separation in a vacuum filter. In the second washing, the precipitate from the first washing was reprecipitated in 2% NH3H2O ​​solution (solid content about 5%) with magnetic stirring at 80°C for 60 min, followed by solid-liquid separation in a vacuum filter to obtain the final NMC precursor solid. The NMC precursor was then dried in an oven at 105°C for 8-10 h to separate the free moisture. After drying, the precipitate is sent for the preparation of coin batteries after lithiation. The final NMC ratio in the precursor is shown in Figure 20.

[0324] Except for sample 8, which was prepared with a true leach solution, all samples NMC 44-52 were prepared with synthetic initial NMC solutions prepared by dissolving analytical grade nickel, cobalt and manganese sulfates in DI water. Some of these synthetic initial NMC solutions contain 20 mg / L Ca and 200 mg / L Mg.

[0325] The chemical composition of the NMC initial solution contained 0.2-0.24 M Ni+Co+Mn (NMC). The NMC molar ratios of the NMC initial solutions are identified by the Y-axis labels in FIG. 20. For example, "NMC44 (initial 6.1:1.8:2.1) pH 9.20" in FIG. 20 indicates that the NMC initial ratio of this NMC initial solution (NMC44 sample) was 6.1:1.8:2.1. In addition, when the precipitation was finished, the final solution pH of "NMC44 (initial 6.1:1.8:2.1) pH 9.20" in FIG. 20 was equal to 9.20.

[0326] Results and Discussion Figure 21 shows Ca 2+ and Mg 2+ The precipitation ranges of Ca and Mg (from initial feed concentrations of 50 mg / L and 200 mg / L, respectively) increased rapidly in the alkaline pH range (8.1-9.3), reaching a maximum of 88.6% for Ca and 71.4% for Mg at pH 9.3, whereas Ca 2+ (5-18%) and Mg 2+ The precipitation rate (1-3%) remains low at pH < 8.3.

[0327] FIG. 22 shows that when the final pH is >8.6, Ni 2+ , Co 2+ and Mn 2+ The precipitation percentage of Ni is significantly higher (98-100%) in the weakly alkaline pH range (8-8.2). 2+ and Co 2+ The precipitation percentages of Mn are still quite similar, ranging from 90 to 100%, while 2+ The precipitation percentage of Ni 2+ and Co 2+ This makes it difficult to precipitate the proper chemical composition of NMC622. 2+ Concentration is C Mn =0.02M (initial 6:2:2) to C Mn = 0.04M (initially 6:3:2) and 0.06M (initially 6:4:2), Mn 2+The precipitation percentage of Ni decreased from ~80% to ~70% in the weakly alkaline pH range (7.6-8.0). 2+ and Co 2+ The precipitation percentage of Mn is almost the same, ranging from 80 to 90%, but 2+ The precipitation percentage of the initial C Mn = 0.06M (initial 6:4:2) is approximately 70%. Note that the initial concentration of Mn was varied during the study to try and achieve a precise final Mn concentration in the precipitate.

[0328] There are some outliers in the Mn precipitation percentages shown in Figure 22. For example, at pH=7.9 (NMC52 sample), Mn 2+ The precipitation percentage of Ni 2+ and Co 2+ This outlier is attributed to the oxidation of Mn from +2 to +4 by air during the NMC precipitation process without N2 gas protection (depletion of N2 gas cylinder). In another replicate test (NMC52-R sample, see Table 10) with N2 gas protection during NMC precipitation, the Mn concentration at pH = 7.87 was 1.01. 2+ The precipitation percentage of NMC was about 70%. The results supported this hypothesis. Further cell performance testing of NMC52 and NMC52-R may reveal whether N2 protection during NMC precipitation is essential for cell performance, as literature suggests that N2 protection during NMC precipitation is necessary. The other outlier data at pH=7.7 is due to a leak in the precipitation reactor.

[0329] The results in Figures 21 and 22 show that Ca 2+ and Mg 2+ In the weakly alkaline pH range (7.6–8.0), where the precipitation percentage of Mn remains low, higher Mn was added to finally achieve a co-precipitated NMC precursor with the appropriate composition for the commercial product. 2+ This article provides guidance on how to prepare an initial NMC solution at a concentration of 0.1 mM NaCl.

[0330] Figure 20 shows the relationship between the NMC ratio in the initial solution and the NMC ratio in the final solid at different precipitation pHs. As discussed in Figure 22, in the slightly alkaline and weakly alkaline pH range (pH 7.6-8.0), Mn 2+ The precipitation percentage of Ni 2+ and Co 2+ Since the pH is lower than the value of NMC622, the NMC ratio in the initial solution was varied from NMC 6:2:2 to 6:3:2 to 6:4:2. For experimental practice, it is difficult to maintain the initial accurate NMC ratio by using analytical sulfate metal salts with different hydration valences. Therefore, the Y-axis of Figure 20 shows the accurate initial NMC ratio, sample name and corresponding final precipitation pH corresponding to NMC 6:2:2, 6:3:2 and 6:4:2, and the X-axis of Figure 20 shows the final NMC ratio in the solid NMC precursor. The results show that several NMC precursors matching the commercially available NMC622 composition were produced, including sample 8 (pH 9.32), NMC44 (pH 9.2), NMC47 (pH 8.63), NMC37-4 (pH 8.08), and NMC49 (pH 7.7). Additionally, there are a number of NMC precursors that match the final NMC ratio of commercially available NMC532, including NMC37-2 (pH 8.06), NMC52 (pH = 7.9), and NMC50 (pH 7.77).

[0331] Preparation of battery materials The purified solution from the leaching process was used to precipitate the NMC622 precursor. The specific NMC co-precipitation conditions are described in the experimental section below. The resulting precursor was then lithiated and calcined to produce the NMC622 cathode material. The battery performance of this NMC622 cathode material is comparable to that of the commercial NMC622 cathode material.

[0332] Experimental - NMC Precipitation Procedure Specifically, the leaching solution (Sample 8-Leach), the purified solution (Sample 8-Purified), and the final solution (Sample 8-Final) of the leaching process are shown in Table 16. To meet the chemical composition of the NMC622 precursor, extra Ni and Mn sulfates were added to the purified solution (Sample 8-Purified) to generate the Sample 8-Final solution that was used directly for NMC precipitation.

[0333] [Table 18]

[0334] 500 mL of NMC initial solution (0.2 M total NMC) was pumped at a rate of 8 mL / min into a 1 L reactor containing 200 mL of ammonium solution (0.1 M). After 3 min, 480 mL of alkaline solution (0.208 M) was started to be pumped into the same reactor at the same flow rate. After 60 min, all the liquid was pumped into the reactor. An overhead mechanical stirrer at 800 rpm was used for mixing in the 1 L reactor. A hot plate was used to heat the reactor to 80 °C under an inert N2 atmosphere. The residence time of the precipitation ranged from 8 to 10 h.

[0335] The reactor was then cooled from 80°C to room temperature. The final slurry was filtered by vacuum filtration to obtain the precipitate. The pH of the final solution (or end point pH) is 9.32. The obtained precipitate went through two stages of washing. The first washing was reprecipitating the precipitate into 0.1M NaOH aqueous solution (solids ~5%) at 80°C for 60 minutes with magnetic stirring, followed by solid-liquid separation in a vacuum filter. The second washing was reprecipitating the precipitate from the first washing into 2% NH3H2O ​​solution (solids ~5%) at 80°C for 60 minutes with magnetic stirring, followed by solid-liquid separation in a vacuum filter to obtain the final NMC precursor solid. The NMC precursor was then dried in an oven at 105°C for 8-10 hours and can be sent for battery preparation. The final NMC ratio in the precursor is 5.8:2.2:2.1, which is in the range of 6:2:2. Analysis is provided in Table 17.

[0336] [Table 19]

[0337] Results – Battery Performance Next, the NMC precursor obtained by the above method is lithiated to prepare the NMC active material. The precursor is first mixed with 5 wt%-exceeding stoichiometric ratio of Li2CO3 as a lithium source. For the calcination process, the mixture is first heated to 400-500°C. ° C for 1 hour, then crushed again and heated in air at 850-900 K. ° The cells were then baked at a high temperature of 100°C for 10 hours. The cathode was prepared by dispersing NMC active (80 wt%), carbon black (10 wt%), and polyvinylidene fluoride (10 wt%) in N-methyl-2-pyrrolidinone. The slurry was then pasted onto an aluminum foil, followed by drying at 100°C for 24 hours. The electrolyte used was LiPF6 (1M) in EC / DMC (1:1 mass ratio). The cells were then packaged in an argon-filled glove box with a lithium metal anode, and the electrochemical performance of these cells was tested over a voltage range of 3.0-4.4V.

[0338] The cell performance of sample 8 cathode at 0.2C shows that the sample has an initial specific capacity of about 163mAh / g (baseline: 170mAh / g) and maintained a capacity of over 163mAh / g after 6 cycles in Table 18. The battery performance is comparable to commercial NMC622 batteries, whose capacities range from 165 to 170mAh / g at the same charge / discharge rates. The sample cathode also exhibits a good hexagonal crystal structure and low Ni-Li intermixing.

[0339] [Table 20]

[0340] Example 3: Precipitation in the presence of impurities Mixed precipitates containing nickel, manganese and cobalt (NMC) were produced from various solutions in the presence of a wide range of impurities. The methodology employed was able to avoid partial or total precipitation of the impurities and produce coprecipitates with electrochemical properties despite the presence of these impurities in the initial solution.

[0341] Tables 19-32 contain the aqueous feed and supernatant coprecipitation ratios from a series of NMC precipitation tests. In interpreting these values, it should be noted that these are NMC:impurity ratios, with lower numbers indicating higher levels of impurity relative to NMC. Thus, a decrease in the ratio after precipitation is evidence of selectivity. The results shown in the tables therefore demonstrate selectivity for each element.

[0342] [Table 21]

[0343] [Table 22]

[0344] [Table 23]

[0345] [Table 24]

[0346] [Table 25]

[0347] [Table 26]

[0348] [Table 27]

[0349] [Table 28]

[0350] [Table 29]

[0351] [Table 30]

[0352] [Table 31]

[0353] [Table 32]

[0354] [Table 33]

[0355] [Table 34]

[0356] Table 33 shows the concentrations (as NMC:element ratios) of a wide range of elements in the aqueous feed solutions (i.e., prior to co-precipitation). This table also includes battery testing to demonstrate that these solutions are capable of producing acceptable co-precipitates with electrochemical performance.

[0357] [Table 35]

[0358] Example 4: Commercial Scale The co-precipitation process has been demonstrated on a commercial scale. Table 34 provides details detailing the starting solution concentrations (aqueous feed solution concentrations) and associated ratios of each element to nickel.

[0359] [Table 36]

[0360] This solution was co-precipitated using a sub-stoichiometric amount of sodium carbonate as the precipitant. The use of a sub-stoichiometric base was used to prevent the majority of the Ca and Mg from precipitating in the process. This method resulted in precipitation ranges of 95%, 80% and 95% for Ni, Mn and Co respectively. Therefore, an additional amount of Mn had to be included in the starting solution to produce on-spec material.

[0361] The coprecipitate obtained from this process was subjected to a series of water and alkaline washing steps to remove Na and S. The final mother liquor and washed solids assays are shown in Table 35.

[0362] [Table 37]

[0363] Based on these final solution and solid compositions, a clear separation can be seen 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 one methodology detailed in the patent to selectively precipitate NMC over some or all of the impurity elements in the presence of the impurity elements. The material was lithiated, calcined, and formed into a battery. The battery demonstrated electrochemical performance, achieving an initial capacity of 163 mAh / g.

[0364] Example 5: Commercial Scale The process described in Example 4 was repeated including the aging process during NMC precipitation. Table 36 details the starting concentrations and the ratios relative to nickel.

[0365] [Table 38]

[0366] The solution was co-precipitated with the stoichiometric base and not with excess Mn. After the co-precipitation was complete, the solution was tank aged for 48 hours. This had the benefit of redissolving some of the precipitated Mg and increasing the efficiency of separation of Mg and Ni. In addition, such a method also allows a higher degree of control over the extent of precipitation of Mg, which is often added to NMC products as a dopant to improve cycling stability. The composition of the product produced in this process is shown in Table 37. The material was lithiated, sintered, and formed into a battery for electrochemical testing. Battery testing yielded an initial capacity of 170 mAh / g.

[0367] [Table 39]

[0368] Example 6: Processing Ni-laterite ore to directly produce NMC Leaching: Nickel laterite ore samples were leached with sulfuric acid to produce a solution suitable for the direct production of NMC precursors. Assays of the material used are given in Table 38. Leaching conditions were 1:1 molar ratio Mg:H2SO4, 10% dry solids loading, 80°C for 6 hours. After leaching, 90% of the nickel, 80% of the magnesium, and various amounts of impurity elements were recovered in solution. The recoveries of all major elements are given in Figure 23 and the composition of the leach solution is given in Table 39.

[0369] [Table 40]

[0370] [Table 41]

[0371] Impurity Removal: The pH of the solution was then used to remove impurities to the level required to use selective co-precipitation. This was achieved by heating the filtrate from the previous leaching step and increasing the pH using aqueous sodium carbonate. Air was pumped into the reactor to oxidize the iron and promote its precipitation as ferric iron. Therefore, a second step was carried out using 30% H2O2 as the oxidant. After this, the solids were separated from the purified solution. The experimental conditions used were 75°C, pH 5.5, 1 hour hold, 200 g / L Na2CO3 as base, air, and the addition of 30% H2O2 as the oxidant in the second stage. The composition of the final purified solution is shown in Table 40.

[0372] [Table 42]

[0373] NMC coprecipitation: Prior to NMC precipitation, the Ni concentration was increased to 2 g / L and the cobalt and manganese were adjusted so that the solution had a 6:4:2 Ni:Mn:Co molar ratio. This ratio adjustment was done using sulfate. NMC precipitation followed the following procedure: 15% Na2CO3 dosing for 6 hours followed by an overnight hold. 75°C, final pH 7.39 was repeated twice. The solution concentrations of major elements before and after this process are shown in Table 41.

[0374] [Table 43]

[0375] The coprecipitate was washed using a three-stage washing process: water displacement wash, water repulp wash, sodium hydroxide repulp wash, and weak ammonia wash. The overall recovery of each major element after the completion of the process is shown in Figure 24. The composition of the final solid produced is shown in Table 42. These results clearly show the high selectivity of Ca / Mg to NMC, even when the Mg concentration is much greater than the NMC metals. This would allow low-grade NMC metal resources such as laterite to be used directly for NMC production.

[0376] [Table 44]

[0377] Battery Test Results: Three cathodes were prepared from the NMC coprecipitates, with an initial capacity of 75 mAh / g and a capacity retention of 84% after 20 cycles.

[0378] Example 7: Processing mixed sulfide ores to directly produce NMC. Leaching: A sample of the sulfide concentrate was leached with sulfuric acid and air to produce a solution suitable for the direct production of NMC precursors. The assays of the material used are given in Table 43. The experimental conditions used were 80°C, 4 days, 10% dry solids loading, H2SO4 dosed to maintain pH at 2, and air flow rate of 0.5 L / min. After leaching, 30% of the nickel was recovered and various amounts of impurity elements. The recoveries of all major elements are given in Figure 25 and the composition of the leachate is given in Table 44.

[0379] [Table 45]

[0380] [Table 46]

[0381] Impurity Removal: The pH of the solution was then used to remove impurities to the level required to use selective co-precipitation. This was achieved by heating the filtrate from the previous leaching step and increasing the pH with aqueous sodium carbonate. Air was pumped into the reactor to oxidize the iron and promote its precipitation 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 sparged as the oxidant.

[0382] NMC Precipitation: Prior to NMC precipitation, the Ni concentration was increased and the cobalt and manganese concentrations were adjusted so that the solution had a Ni:Mn:Co molar ratio of 6:3:2. This ratio adjustment was done using high purity sulfate. NMC precipitation was carried out using the following procedure: 5% Na2CO3 dosing for 6 hours followed by an overnight hold at 75°C with a final pH of 7.85. The solution concentrations before and after this process are shown in Table 45.

[0383] [Table 47]

[0384] The coprecipitate was then washed in three stages: water displacement wash, water repulp wash, sodium hydroxide repulp wash, and weak ammonia wash. The overall recovery of each major element after the process was completed is shown in Figure 26. The composition of the final solid produced is shown in Table 46.

[0385] [Table 48]

[0386] Example 8: Leaching example of a mixture of cobalt concentrate and black lump A 50% blend of cobalt concentrate and black mass was leached with SO2 to produce a solution suitable for the direct production of NMC. Assays of the materials used are given in Table 47. The experimental conditions were 55°C, 2 hours 40 minutes, 5% dry solids loading, SO2 sparged to 200% stoichiometric over 2 hours. After leaching, 30% nickel and various amounts of impurity elements were recovered. The recoveries of all major elements are given in Figure 27 and the composition of the leachate is given in Table 48.

[0387] [Table 49]

[0388] [Table 50]

[0389] After this, the pH of the solution is raised to 5.5 while sparging with air. This condition should be maintained for at least 1 hour to allow sufficient time for the Fe to precipitate. Using this process, impurities such as Al, Fe, Cu, Cr and Zn should be sufficiently removed so that selective precipitation can be used. The solution will then have the molar ratio of Ni, Mn and Co adjusted to 6:2:2, suitable for the production of NMC.

[0390] Example 9: Washing of the coprecipitate Immediately after co-precipitation, the solid formed is subjected to successive washing procedures which may include water, basic (carbonate, hydroxide or ammonia) washes or acid washes. The exact washing method selected depends on the impurities present. In this example, a batch of about 1 tonne of wet NMC was produced on a commercial scale. It was then subjected to a water wash at 60:1 water:dry solids by weight, followed by a caustic soda reslurry wash at 7% solids using 10% aqueous sodium hydroxide, followed by a final water wash at 40:1 water:dry solids by weight. The assays for this sequence of procedures are shown in Table 49. The washing steps are successful in removing some impurity elements and improving the NMC:impurity ratio of impurity elements such as Ca, Cu, K, Mg, Na, S and Zn.

[0391] [Table 51]

[0392] 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 belongs.

[0393] In this specification and the claims (if any), the words "comprises" and "comprising" and derivatives thereof, including "comprising", include each of the listed integers but do not exclude the inclusion of one or more additional integers.

[0394] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0395] In accordance with the statute, the invention has been described in language more or less specific to structural or methodological features. It is to be understood that the invention is not limited to the specific features shown and described, since the means described herein include preferred forms for carrying out the invention. The invention is therefore claimed in any of its forms or modifications within the proper scope of the appended claims (if any) as appropriately interpreted by those skilled in the art.

Claims

1. 1. A method for making a coprecipitate, the method comprising: adjusting the pH of an aqueous feed solution containing at least two metals and impurities to about 6.2 to about 11 to provide a coprecipitate and a supernatant; and separating the coprecipitate from the supernatant; the at least two metals are selected from nickel, cobalt and manganese; the impurity is at least one selected from 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, and niobium, or a combination thereof; a weight ratio of said at least two metals to said impurities in said aqueous feed solution is less than 50,000:1; The coprecipitate comprises: - nickel, if present in the aqueous feed solution; - cobalt, if present in the aqueous feed solution; and manganese, if present in the aqueous feed solution; Including; And The method of claim 1, wherein the supernatant comprises at least one of the impurities; and the supernatant comprises greater 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 about 6.2 to less than 10.

3. The method according to claim 1 or claim 2, further comprising washing the separated coprecipitate with an alkaline wash.

4. 4. The method of claim 1, wherein the impurity is at least one 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 a combination thereof.

5. The method of any one of claims 1 to 4, wherein the mass ratio of said at least two metals to said impurities in the aqueous feed solution is less than 5,000:

1. (i) a molar ratio of the at least two metals to alkaline earth metal impurities in the aqueous feed solution is less than 200:1; or The method of any one of claims 1 to 5, wherein (ii) the ratio of said at least two metals to metal impurities and metalloid impurities is less than 500,000:

1.

7. The method of any one of claims 1 to 6, wherein the pH of the aqueous feed solution is adjusted to from about 6.2 to about 9.

2.

8. The method of any one of claims 1 to 7, wherein the aqueous feed solution comprises cobalt, manganese and nickel.

9. Prior to the step of adjusting the pH of the aqueous feed solution, the process further comprises: providing a feed mixture comprising at least one metal selected from nickel, cobalt and manganese, said feed mixture being defined as one of an oxidized feed, a reduced feed or an unoxidized feed; the oxidation feed has more of at least one metal in an oxidation state greater than 2 than in an oxidation state less than 2; The reduced feed has more of the at least one metal in an oxidation state less than 2 than in an oxidation state greater than 2, or has substantially all of the at least one metal in an oxidation state of 2 and at least a portion of the at least one metal in sulfide form; and the unoxidized feed has substantially all of at least one metal in oxidation state 2 and substantially none of at least one metal in sulfide form; treating the feed mixture with an aqueous solution to form a leachate comprising the at least one metal, the pH of the aqueous solution being such that the leachate has an end pH of from about 1 to about 6; When the feed mixture is an oxidizing feed, the treatment additionally comprises the addition of a reagent comprising a reducing agent; and When the feed mixture is a reduced feed, the treatment additionally comprises adding a reagent comprising an oxidizing agent; Thus, the leachate contains at least one of nickel, cobalt and manganese in the oxidation state 2. The method of any one of claims 1 to 8, wherein the exudate is used to feed the aqueous feed solution.

10. 10. The method of any one of claims 1 to 9, wherein the supernatant contains more than 1000 mg of nickel, cobalt or manganese.

11. 11. The method of any one of claims 1 to 10, wherein prior to 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, cementation and sedimentation, or combinations thereof.

12. 12. The method of any one of claims 1 to 11, wherein prior to 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 combinations thereof.

13. 13. The method of any one of claims 1 to 12, 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 a desired molar ratio in the coprecipitate.

14. 14. The method of claim 13, wherein the desired ratio is 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.

15. The method of any one of claims 1 to 14, wherein the step of separating the coprecipitate from the supernatant comprises decanting and / or filtering to isolate the coprecipitate.

16. 16. The method of any one of claims 1 to 15, additionally comprising mixing the coprecipitate with lithium to provide a mixture.

17. The method of claim 16 further comprising the step of baking the mixture.

18. 20. The method of claim 17, wherein the calcined lithiated co-precipitate provides a battery performance greater than 10 mAh / g.

19. The coprecipitate is (a) Less than 10,000 parts per million alkaline earth metals, calculated on dry solids; or (b) Less than 10,000 ppm metal and metalloid impurities calculated on the dry solids. The method according to any one of claims 1 to 18, comprising:

20. 20. The method according to any one of claims 1 to 19, wherein the method further comprises scavenging nickel and / or cobalt and / or manganese remaining in the supernatant by precipitation and / or ion exchange.

21. 21. The method of any one of claims 1 to 20, wherein adjusting the pH of the aqueous feed solution comprises adding a precipitating agent to the aqueous feed solution, the precipitating agent being added in a sub-stoichiometric amount with respect to at least two metals.

22. A coprecipitate comprising at least two metals selected from nickel, cobalt and manganese, the coprecipitate being produced by a method according to any one of claims 1 to 21.

23. Use of the coprecipitate according to claim 22 for producing a lithium ion battery.

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