Recycling e-waste to recover lithium

Abstract

Disclosed herein is a method for recovering metals from e-waste or its leach residue, where the e-waste or leach residue comprises elemental copper and one or more lithium compounds, the method comprising: leaching the e-waste or leach residue with a leach solution comprising ammonium sulfate in the presence of an oxidizing agent to provide a leachate and a solid residue comprising Cu ions and Li ions; and separating the leachate and solid residue.

Description

[Technical Field]

[0001] The present invention relates generally to a method for recovering lithium and optionally other transition metals from waste electronic materials comprising at least copper and one or more lithium salts, and particularly when the waste electronic materials are waste lithium-ion batteries. [Background technology]

[0002] The use of discarded electronics, particularly rechargeable Li-ion batteries, worldwide has grown rapidly in recent years and is set to expand further in the emerging markets of electric vehicles and large-capacity power storage. As demand for electronic devices, particularly those using Li-ion batteries, increases, so does the demand for the metal / metal oxide components used in these devices. The rapid increase in demand for some of these metals, such as cobalt, is putting pressure on the sustainable supply of such resources. This is rapidly increasing the cost of such metals.

[0003] There has been little interest in developing processes for the recovery and reuse of various components in modern electronic devices and their components (e.g., batteries). In the case of batteries, this is primarily due to the relatively small volume of Li-ion batteries available for reuse and the relatively high cost of the typical pyrometallurgical and hydrometallurgical processes by which recovery is achieved. As demand for Li-ion batteries continues to increase, so too does the volume of spent Li-ion batteries available for reuse. Low-cost, efficient recycling processes are needed, especially for the more complex metal / metal oxide components. While the following discussion primarily concerns Li-ion batteries, they are applicable to a variety of electronic devices, as they similarly incorporate a variety of different metal compounds.

[0004] The composition of Li-ion batteries has evolved considerably in recent years. While several battery recycling processes have been developed, these have primarily been limited to the recovery of certain metals from certain types of batteries or sources. For example, early batteries were primarily lithium-cobalt, and recovery methods focused on recovering cobalt. As lithium demand increased, recovery methods shifted to recovering both cobalt and lithium. As battery technology further developed, cathodes incorporated other metals, such as manganese, nickel, aluminum, iron, and phosphorus. The methods used to recover lithium and cobalt are not suitable for the recovery of other metals, nor are they well suited to different battery chemistries.

[0005] The incorporation of Li-ion batteries into use increases the volume of spent Li-ion batteries available for recycling. However, the supply of spent Li-ion batteries contains many different types of batteries. The suitability of recovery methods to only a single battery type presents significant challenges to the commercialization of such processes. Specifically, such methods require one or more sorting and pretreatment steps. Given this, there is a need to develop processes for recovering a range of metals from a range of different Li-ion battery types.

[0006] Most developments in battery recycling involve dissolving metal components in an acidic medium. This is a non-selective leaching process in which most of the metals contained in the battery are dissolved. Batteries contain significant amounts of various non-valuable metals, such as iron, manganese, and aluminum. Some batteries may also contain phosphorus. If these non-valuable metals and phosphorus are not removed prior to leaching, acid consumption is high. As a result, pretreatment processes are required to separate iron and aluminum from valuable metal components such as cobalt, nickel, copper, and lithium. In doing so, recovery of these valuable metals is reduced because the separation achieved in these pretreatment processes is not 100% efficient.

[0007] It is desirable to provide a method for recovering metals, particularly lithium, from discarded electronic devices such as batteries of a wide range of chemistries.

[0008] It is an object of the present invention to address one or more of the shortcomings of the prior art and / or to provide a useful alternative. Summary of the Invention

[0009] In one aspect of the present invention, there is provided a method for recovering metals from e-waste or leaching residues thereof, wherein the e-waste or leaching residues comprise elemental copper and one or more lithium compounds, and the method comprises: leaching the electronic waste or leach residue with a leach solution comprising ammonium sulfate in the presence of an oxidizing agent to provide a leach solution and a solid residue comprising Cu and Li ions; and separating the leachate and the solid residue.

[0010] Elemental copper means copper metal.

[0011] In one embodiment, the e-waste comprises, consists of, or consists essentially of one or more types of lithium ion batteries, preferably in the form of lithium ion battery fragments. In an alternative embodiment, the e-waste comprises a mixture of one or more types of lithium ion batteries with other e-waste, such as printed circuit boards.

[0012] In one embodiment, the one or more lithium compounds comprise lithium metal oxides and / or lithium metal phosphates, such as in the form of LiMO2, LiMPO4, where M is one or more metals selected from the group consisting of Al, Co, Mn, and / or Ni. In a preferred form, the one or more lithium metal compounds are LiNi w Co x Al y Mn z O2 (wherein w+x+y+z=1), and / or LiNi x Mn y Co 1-x-y O2 (wherein 0≦x+y≦1), and / or LiNi x Co y Al zO2 (where x+y+z=1), and / or LiFePO4.

[0013] In one embodiment, the Cu and Li ions are in the form of CuSO4 and Li2SO4, respectively.

[0014] In one embodiment, elemental copper is present in an amount sufficient to provide a redox potential of -100 mV or less, as determined using an Ag / AgCl reference electrode. Preferably, the redox potential is -150 mV or less. The inventors have found that a redox potential of -100 mV or less is useful for ensuring the solubilization of Li ions and the reduction of transition metals in e-waste. In particular, the inventors have found that a redox potential of -100 mV or less is important for forming soluble Mn ions. When the redox potential is greater than -100 mV, Mn gradually migrates to the solid residue.

[0015] In one embodiment, the oxidizing agent is present in an amount sufficient to provide a redox potential of +50 mV or greater, as determined using an Ag / AgCl reference electrode, preferably +100 mV or greater, and more preferably +150 mV or greater.

[0016] In one embodiment, elemental copper is present in an amount of at least 4 wt.% based on the total weight of the e-waste. Preferably, elemental copper is present in an amount of at least 5 wt.%. More preferably, elemental copper is present in an amount of at least 6 wt.%. Even more preferably, elemental copper is present in an amount of at least 7 wt.%. Most preferably, elemental copper is present in an amount of at least 8 wt.%.

[0017] In one embodiment, the oxidizer comprises, consists of, or consists essentially of a solid oxidizer. More preferably, the oxidizer is in the form of a metal oxide present in the e-waste, particularly an oxide of Co, Mn, or Ni. In some embodiments, the oxidizer is a component of one or more lithium compounds, such as the Co, Mn, and / or Ni components of a lithium metal oxide.

[0018] The inventors have found that the leaching process mediates a redox reaction between elemental copper and Co, Mn, and Ni salts, which advantageously results in the formation of soluble salts of Co, Cu, Mn, and Ni ions.

[0019] In embodiments where Ni is present, the Cu:Ni ratio is 0.5:1 or greater, for example, up to about 2:1.

[0020] In embodiments where Co is present, the Cu:Co ratio is 0.5:1 or greater, for example, up to about 2:1.

[0021] In embodiments where Mn is present, the Cu:Co ratio is 0.5:1 or greater, for example, up to about 2:1.

[0022] In embodiments where both Ni and / or Co and / or Mn are present, it is preferred that the Cu:(Ni+Co+Mn) ratio is 0.5:1 or greater, for example up to about 2:1.

[0023] In one embodiment, the temperature is from about 0° C. to a temperature up to the boiling point of the leaching solution at the operating conditions of the leaching, e.g., less than 100° C. Preferably, the temperature is from about 40° C. Preferably, the temperature is up to about 60° C.

[0024] In one embodiment, the leaching is carried out at atmospheric pressure.

[0025] In one embodiment, leaching is carried out for up to 24 hours. Preferably, leaching is carried out for up to 18 hours. More preferably, leaching is carried out for up to 12 hours. Most preferably, leaching is carried out for up to 8 hours. Additionally or alternatively, leaching is carried out for at least 0.5 hours. Preferably, leaching is carried out for at least 1 hour. More preferably, leaching is carried out for at least 1.5 hours. Most preferably, leaching is carried out for at least 2 hours.

[0026] In one embodiment, the method further comprises recovering Cu ions from the leachate. Preferably, the Cu ions are recovered using a solvent extraction process comprising contacting the leachate with an extractant to adsorb the Cu ions onto the extractant to form a Cu-loaded extractant, and separating the Cu-loaded extractant from the leachate. More preferably, the method further comprises stripping the Cu ions from the Cu-loaded extractant using a stripping agent, such as sulfuric acid.

[0027] In one aspect of the above embodiment, after the step of recovering Cu ions from the leachate, the method further comprises: crystallizing ammonium lithium sulfate from the leachate; and thermally decomposing the crystallized lithium ammonium sulfate to form a gas containing ammonia and sulfur oxides and solid lithium sulfate.

[0028] Preferably, prior to the step of crystallizing the lithium ammonium sulfate, the leachate is treated so that the leachate is an ammonia, Cu, Ni, Co, Mn dilute leachate and / or so that the leachate is substantially free of ammonia, Al, Cu, Fe, Ni, Co, or Mn.

[0029] Preferably, prior to the step of crystallizing ammonium lithium sulfate, the leachate contains ammonia, Cu, Ni, Co, and Mn at concentrations of 100 mg / L or less each, preferably 80 mg / L or less each, and most preferably 60 mg / L or less each.

[0030] In one embodiment, the e-waste further comprises one or more transition metal salts, more preferably transition metal oxides. In such cases, it is more preferred that the oxidizing agent is one or more transition metal salts or oxides and the leachate comprises ions of one or more transition metals.

[0031] In one form of the above embodiment, the one or more transition metal salts are components of a lithium metal oxide and / or a lithium metal phosphate.

[0032] In one form of the above embodiment, the one or more transition metals are selected from the group consisting of Co, Mn, and / or Ni.

[0033] If the e-waste further comprises one or more transition metal salts, it is further preferred that the leaching is an alkaline leaching and that the leach solution comprises a sufficient amount of ammonia to provide a pH of about 8.5 to about 10.5. More preferably, the leach solution further comprises ammonium chloride. Preferably, the ammonium chloride is present at a concentration of at least 1 g / L.

[0034] In one embodiment, the leaching is an alkaline leaching.

[0035] In one form of the above embodiment, the leach solution further comprises ammonia and / or ammonium chloride. Preferably, the ammonia is present in an amount sufficient to provide a leach solution with a pH of from about 8.5 to about 10.5. Preferably, the ammonium chloride is present at a concentration of at least 1 g / L.

[0036] In one embodiment, the e-waste further comprises one or more Ni salts, preferably in the form of Ni oxides, and the leach solution further comprises ammonia in an amount such that the pH of the leach solution is from about 8.5 to about 10.5, the leach solution comprising at least Cu, Li, and Ni ions. Preferably, the pH is from about 9. More preferably, the pH is up to about 10.

[0037] In one form of the above embodiment, the leach solution comprises ammonia and ammonium sulfate in a ratio of about 1:2 to about 1:20.

[0038] In one aspect of the above embodiment, the ratio of Cu:Ni is from about 2:1 to about 0.5:1.

[0039] In one aspect of the above embodiment, the method further includes simultaneously recovering Cu and Ni from the leachate via a solvent extraction process. Preferably, the solvent extraction process includes contacting the leachate with an extractant to adsorb Cu and Ni ions in the extractant to form a Cu, Ni-loaded extractant, and separating the Cu, Ni-loaded extractant from the leachate. More preferably, the method further includes stripping Cu and Ni ions from the Cu, Ni-loaded extractant using a stripping agent, such as sulfuric acid, wherein Ni ions are selectively recovered at a first stripping agent concentration and Cu ions are subsequently recovered at a second stripping agent concentration, the first stripping agent concentration being less than the second stripping agent concentration.

[0040] In one embodiment, the e-waste further comprises Co, the leach solution further comprises ammonia in an amount such that the pH of the leach solution is from about 8.5 to about 10.5, and the leach solution comprises at least Cu, Li, and Co ions.

[0041] In one aspect of the above embodiment, the ratio of Cu:Co is from about 2:1 to about 0.5:1.

[0042] In one form of the above embodiment, the method further includes recovering Cu ions from the leachate and precipitating Co from the leachate after removal of the Cu ions.

[0043] Preferably, the step of precipitating Co from the leachate comprises precipitating cobalt sulfides from the leachate. In embodiments in which Ni and / or Mn are present in the e-waste, the step of precipitating Co from the leachate occurs after recovery of Mn and / or Ni. That is, prior to the step of precipitating Co, the leachate is preferably substantially free of Cu, Mn, and Ni. By way of example, the leachate contains Cu and / or Mn and / or Ni at concentrations of 100 mg / L or less, each of which is more preferably 80 mg / L or less, and most preferably 60 mg / L or less. This is to minimize co-precipitation of sulfides of Cu, Mn, and Ni, thus providing a higher purity cobalt product.

[0044] In one embodiment, the e-waste further comprises Mn, the leachate further comprises a leachate containing Mn, and the method further comprises: treating the leachate with an oxidizing agent to form a precipitate of Mn and provide a Mn-dilute leachate containing Cu and Li ions; and separating the Mn precipitate from the Mn dilute leachate.

[0045] In one form of the above embodiment, the oxidant is air.

[0046] In one aspect of the above embodiment, the ratio of Cu:Mn is from about 2:1 to about 0.5:1.

[0047] In one embodiment, the e-waste further comprises Fe and Al, the solid residue comprises Fe and Al, the leachate is an Fe-, Al-dilute leachate, and / or the leachate is substantially free of Fe or Al.

[0048] In one embodiment, the leachate contains Fe and Al at a concentration of 100 mg / L or less each, more preferably 80 mg / L or less each, and most preferably 60 mg / L or less each.

[0049] In one embodiment, the e-waste comprises elemental copper and one or more compounds of Co, Li, and Ni, and the leach solution further comprises ammonia, and the leachate comprises Co ions, Cu ions, Li ions, and Ni ions, and after separating the leachate from the solid residue, the method comprises subjecting the leachate to a solvent extraction process to remove Cu ions and Ni ions from the leachate to form a Cu,Ni-dilute leachate; subjecting the Cu,Ni-dilute leachate to a precipitation step to remove Co ions from the Cu,Ni-dilute leachate to form a Co,Cu,Ni-dilute leachate; and recovering Li from the Co, Cu, Ni dilute leachate; The method, wherein prior to the step of recovering Li, the leach solution is subjected to an ammonia recovery step such that the Co-, Cu-, Ni-dilute leach solution is substantially free of ammonia during recovery of Li.

[0050] In one aspect of the above embodiment, the Co ions are Co 2+ ions, and prior to subjecting the leachate to a solvent extraction step, the method includes treating the leachate with an oxidizing agent to remove Co ions. 2+ ions to Co 3+ further comprising oxidizing to ions.

[0051] In one embodiment, the e-waste comprises elemental copper and one or more compounds of Co, Li, Mn, and Ni, the leach solution further comprises ammonia, the leachate comprising Co ions, Cu ions, Li ions, Mn ions, and Ni ions, and after separating the leachate from the solid residue, the method further comprises: The leachate is treated with an oxidizing agent to form precipitates of Mn and Co. 3+ providing a Mn dilute leach solution containing Co ions, Cu ions, Li ions, and Ni ions in ionic form; Separating the Mn precipitate from the Mn dilute leachate; subjecting the Mn dilute leachate to a solvent extraction step to remove Cu ions and Ni ions from the Mn dilute leachate to form a Cu, Mn, Ni dilute leachate; subjecting the Cu-, Mn-, Ni-dilute leachate to a precipitation step to remove Co ions from the Cu-, Mn-, Ni-dilute leachate to form a Co-, Cu-, Mn-, Ni-dilute leachate; and recovering Li from the dilute Co-, Cu-, Mn-, Ni- leachate; The method, wherein prior to the step of recovering Li, the leach solution is subjected to an ammonia recovery step such that the Co-, Cu-, Ni-dilute leach solution is substantially free of ammonia during recovery of Li.

[0052] In one embodiment, the leach solution further comprises ammonia, the leachate is a first leachate, and the solid residue is a first solid residue, and after the step of separating the first leachate from the first solid residue, the method further comprises: leaching the solid residue with a second leach solution comprising ammonium sulfate to provide a second leach solution and a second solid residue; separating the second leachate and the second solid residue; leaching the second solid residue with an acid to provide a third leachate and a third solid residue; separating the third leachate and the third solid residue; combining the first infusion solution, the second infusion solution, and the third infusion solution to form a combined infusion solution.

[0053] In one form of the above embodiment, the e-waste includes elemental copper and one or more compounds of Co, Li, Mn, and Ni, and the method includes recovering one or more of Co, Cu, Li, Mn, and Ni from the combined leachate.

[0054] In one embodiment, the leach solution is substantially acid-free and / or free of added acid species. In some cases, the natural pH of the leach solution during leaching is less than 7. In such cases, this is due to acid species generated during the leaching process. Thus, in a preferred form of the invention, any acid present in the leach solution is generated during leaching from e-waste.

[0055] In one embodiment, the leaching solution is substantially free of organic compounds. For example, the leaching solution is free of monomers, oligomers, polymers, surfactants, organic leaching agents, organic acids, organometallic compounds, and the like.

[0056] In one embodiment, the infusion solution is substantially free of biological material. For example, the infusion solution is free of vegetable, fruit, or animal biological material.

[0057] In one embodiment, the method includes subjecting e-waste to a first leaching with a first leach solution to provide a first leachate and a solid residue, and leaching the leach residue with a leach solution comprising ammonium sulfate in the presence of an oxidizing agent to provide a leachate and solid residue comprising Cu and Li ions.

[0058] Those skilled in the art will appreciate that there may be additional leaching steps between the first leaching and the step of leaching the leach residue, for example there may be a second leaching with a second leach solution resulting in a second leachate and a second leach residue, and the step of leaching the leach residue is one of leaching the second leach residue.

[0059] The first leach (and, in various embodiments, the second leach) may be, for example, an acid leach, an alkaline leach, or the like. However, it is preferred that the first and / or second leach solutions include one or more of ammonia, ammonium sulfate, and ammonium chloride. In such embodiments, the first and / or second leach solutions comprise, consist of, or consist essentially of solutions of: (i) ammonia and ammonium chloride; (ii) ammonia and ammonium sulfate; (iii) ammonium sulfate and ammonium chloride; and (iv) ammonia, ammonium chloride, and ammonium sulfate. In embodiments, the leach solution is combined with the first leach solution (and the second leach solution in embodiments including a second leach step) to form a combined leach solution from which Cu and Li, along with Co, Mn, and Ni, if present, may be recovered generally according to the methods described above.

[0060] The reference herein to any prior art is not an admission or suggestion that that prior art forms part of the common general knowledge in any jurisdiction, or that that prior art would be understood by, considered relevant, and / or could reasonably be expected to be combined with other pieces of prior art by a person skilled in the art.

[0061] As used herein, unless the context requires otherwise, the term "comprise" and variations of this term such as "comprising", "comprises" and "comprised" are not intended to exclude further additional elements, components, integers or steps. [Brief explanation of the drawings]

[0062] Further aspects of the invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example, and with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a process flow diagram illustrating the method of the present invention in accordance with one embodiment of the present invention. [Figure 2] FIG. 2 is a process flow diagram illustrating the method of the present invention in accordance with another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0063] The present invention relates generally to a method for recovering valuable metals, particularly lithium, from electronic waste containing elemental copper and one or more lithium-containing salts.

[0064] This method involves leaching e-waste with ammonium sulfate, during which elemental copper is oxidized to copper ions, thus providing an electron source that acts as a reducing agent, thereby producing soluble lithium ions from lithium-containing salts. If transition metals such as cobalt, manganese, and nickel are present in the e-waste, for example as components of lithium-containing salts or as metal oxides, they are similarly reduced to soluble ions. Various soluble metal ions, particularly lithium, can be selectively recovered as products. Ammonium sulfate can also be recovered and reused for further leaching.

[0065] The method is particularly applicable to the recovery of lithium from discarded lithium-ion batteries, especially battery fragments (whether a single type of battery or a mixture of battery fragments from different lithium-ion batteries). The method can be advantageously applied to raw battery fragments, i.e., battery fragments (as opposed to black mass) that have not undergone pre-treatment processes such as copper stripping and / or calcination. As non-limiting examples, the method may be applied to extract Co, Cu, Li, Mn, and Ni ions, depending on the chemistry of the battery or mixture of batteries in the battery fragments.

[0066] In a preferred form of the invention, the e-waste comprises lithium ion batteries containing lithium metal oxide or lithium metal phosphate, a non-limiting disclosure of which includes nickel manganese cobalt (NMC), lithium cobalt oxide (LCO), and lithium manganese oxide (LMO), lithium iron phosphate (LFP), and lithium nickel cobalt aluminum oxide (NCA) batteries, and mixtures thereof. Generally, in these batteries, the lithium is represented by LiMO2, LiMPO4, where M is a transition metal, and / or LiNi x Co y Al z O2, where x+y+z=1. The electronic waste may further include other electronic waste, such as printed circuit boards.

[0067] While not wishing to be bound by theory, the inventors believe that ammonium sulfate leaching mediates the oxidation-reduction of copper, which ultimately provides an electron source and soluble copper salts, and in doing so reduces lithium metal salts (such as those described above) to liberate Li ions into solution, and optionally Cu, Co, Mn, and Ni ions depending on the Li-ion battery chemistry in the battery fragments. Leaching is selective in that low-value metals such as iron and aluminum that may be present in the e-waste are substantially retained in the solid residue along with low-value phosphate compounds.

[0068] More specifically, during ammonium sulfate leaching, copper metal is oxidized to Cu(I). Cu(I) is then oxidized to Cu(II) via a redox reaction with lithium metal salts or other transition metal salts, resulting in the formation of soluble ions of Li and / or Co, Mn, and Ni (if present). The redox reaction stops in the absence of a copper metal source acting as a reductant or a balance of lithium metal salts and / or other transition metal salts acting as oxidants to convert Cu(I) to Cu(II). Generally, the method provides sufficient oxidant (in the form of lithium metal salts and / or other transition metal salts) and sufficient copper to allow the reaction to proceed to completion. If there is insufficient oxidant in the form of lithium metal salts and / or other transition metal salts, additional oxidant, such as air, hydrogen peroxide, or hypochlorite, may be added.

[0069] The inventors have also found that introducing ammonium chloride during leaching, or including it as a component of the leaching solution, is useful as it improves the stability of the Cu(I) ions in solution, thus resulting in more effective and efficient leaching.

[0070] The resulting leachate generally contains at least Cu and Li ions, and may additionally contain Co, Mn, and Ni ions depending on the composition of the e-waste. If present, the Co, Mn, and Ni ions may be selectively recovered according to the methods described herein.

[0071] If the leachate contains Cu and Li ions, the Cu ions may be recovered by a solvent extraction process, i.e., contacting the leachate with an extractant to recover the Cu ions from the leachate and form a Cu-loaded extractant. The extractant is then stripped with a stripping agent, such as sulfuric acid, to yield CuSO. 4(水溶液) Cu can be recovered in the form of

[0072] The substantially Cu-free leachate can then be treated to recover ammonium sulfate and Li. The inventors have discovered that ammonium lithium sulfate can be crystallized from the leachate by concentrating the leachate, for example by evaporating water from the leachate, to crystallize the ammonium lithium sulfate. The ammonium lithium sulfate can then be recovered by a solid-liquid separation process (e.g., filtration, centrifugation, etc.) and then thermally decomposed into lithium sulfate crystals, ammonia gas, and sulfur trioxide gas. The sulfur trioxide gas can be reacted with ammonia gas and water to regenerate ammonium sulfate.

[0073] If other transition metal ions, such as ions of Co, Mn, and Ni, are present in the leachate, they may be selectively recovered prior to the recovery of lithium. In embodiments in which Co, Mn, and Ni are present, it is preferred to recover Cu and Ni, and then recover Mn from the leachate before recovering Co.

[0074] In embodiments where Mn is present, Mn ions can be recovered via oxidation of Mn to manganese oxides, such as MnO, MnO, and / or MnO (but not MnO), with air being a suitable oxidant. If Co(II) ions are present during the oxidation process, they are oxidized to Co(III) ions. To prevent CoO precipitation, in addition to oxidizing Co(II) ions to Co(III) ions, the Mn recovery step is preferably carried out in the presence of ammonia, as ammonia forms a stable, soluble sulfate complex with Co ions, as described above, thus mitigating CoO precipitation during the oxidation process. Co ions can then be recovered by precipitation using a variety of different salts, such as carbonates and / or sulfides.

[0075] In embodiments involving Ni and / or Co, the inventors have also found it useful to introduce ammonia during leaching or to include ammonia as a component of the leach solution, as it complexes with Ni and / or Co to form soluble Ni and / or Co ammonium sulfate salts that are stable, particularly at pH values ​​in the range of 9 to 10. This aids in the selective extraction and recovery of Ni and / or Co.

[0076] In embodiments where the leachate contains both Ni and Co ions, it is preferred that the Cu and Ni ions are extracted simultaneously from the leachate, followed by recovery of the Co ions, and then the Li ions, although those skilled in the art will appreciate that these metal ions may be extracted or otherwise recovered from the leachate in a different order and / or other metal ions may be recovered from the leachate at intervening stages before or potentially after lithium recovery.

[0077] Ni ions can be extracted simultaneously with Cu ions by solvent extraction. To facilitate this, the method may include an upstream oxidation step to oxidize Co ions to Co(III). This prevents cobalt from being recovered during solvent extraction, thus preventing poisoning of the extractant by Co(II) ions. Ni ions can then be selectively stripped from the extractant using a stripping agent before stripping the Cu ions. The extractant is preferably sulfuric acid, in which case Ni ions can be stripped at a relatively lower sulfuric acid concentration than Cu ions, thereby allowing selective recovery of Ni and Cu ions. Co can then be recovered from the leachate by, for example, precipitation with sulfides.

[0078] If ammonia is present, it can be recovered prior to the recovery of lithium. The ammonia can be steam stripped from the leach solution.

[0079] If ammonium chloride is present, it will be retained in the leachate and can be reused after recovering lithium from the leachate (in the form of lithium ammonium sulfate as described above).

[0080] The present invention is described below in connection with embodiments thereof, which are intended to be exemplary in nature and should not be construed as limiting.

[0081] Embodiment 1. This embodiment describes a method for recovering metals from a feed containing electronic waste, including one or more lithium-ion battery types. In this embodiment, the feed contains copper metal and metal oxides of at least cobalt, lithium, and nickel.

[0082] The method includes an initial leaching step in which lithium-ion battery waste (which may be mixed with other electronic waste sources) is subjected to alkaline leaching with a first leaching solution containing ammonium sulfate. In this embodiment, the first leaching solution additionally contains ammonia and ammonium chloride, both of which have been found to enhance the leaching process. Ammonia aids in the formation of stable soluble complexes of Ni and Co, while ammonium chloride promotes the stability of Cu(I), thus increasing the effectiveness of the leaching. Leaching is carried out at atmospheric pressure and ambient temperature. However, leaching may also be carried out at elevated temperatures, for example, at temperatures below the boiling point of the leaching solution.

[0083] Alkaline leaching oxidizes elemental copper contained in lithium-ion batteries to soluble copper ions, which then provide a source of electrons for reducing or otherwise liberating the cobalt, lithium, and nickel ions contained in the batteries. Thus, leaching results in the formation of a leachate containing soluble ions of copper, cobalt, lithium, and nickel, as well as a solid residue. The inventors have found that a significant proportion of the contained cobalt, nickel, copper, and lithium, e.g., greater than about 90% of the nickel, copper, and cobalt, and greater than about 70% of the lithium, is leached into solution. Similarly, a significant proportion of the aluminum and iron contained in the batteries, e.g., greater than about 99% of the aluminum and iron, is retained in the solid residue.

[0084] The leachate can be subjected to a solvent extraction process for the extraction of copper and / or nickel. The copper- and / or nickel-loaded solvent can then be separated from the combined leachate, and the copper and / or nickel are then recovered from the solvent. Copper and nickel can be recovered from the solvent via stripping with a stripping agent such as sulfuric acid. Generally, nickel can be selectively stripped at a lower residual acid concentration than copper, for example, in the pH range of about 1 to 4, and copper is then stripped by increasing the acid concentration, for example, to above about 50 g / L H2SO4. This two-stage stripping allows copper and nickel to be selectively recovered in separate streams.

[0085] The leachate can then be subjected to further processing to recover the cobalt. In this embodiment, the cobalt is recovered via a cobalt precipitation process in which the leachate is treated with a sulfide, such as hydrogen sulfide or ammonium sulfide, to precipitate cobalt sulfide. The cobalt sulfide can then be recovered from the combined leachate using any solid-liquid separation process commonly known to those skilled in the art, such as filtration.

[0086] The leach solution, now substantially depleted of cobalt, copper, and nickel, can be further processed to recover ammonia, ammonium salts, and lithium.

[0087] Ammonia is steam stripped from the leachate, and the recovered ammonia is recycled and reused as a component of the first leach solution. The lithium in the leachate is generally in the form of lithium sulfate. This lithium sulfate can be crystallized with ammonium sulfate (e.g., via an evaporation process) in the form of lithium ammonium sulfate and separated from the leachate. The lithium ammonium sulfate can then be subjected to thermal treatment to decompose the lithium ammonium sulfate into lithium sulfate solids, ammonia gas, and sulfur trioxide gas. The ammonia and sulfur trioxide gas can be captured and reacted with water, such as in a wet scrubber, to form ammonium sulfate, which can then be recycled to the first and / or second leach steps.

[0088] Embodiment 2. The present embodiment describes a method for recovering metals from a feed containing one or more lithium-ion battery types. In this particular embodiment, the feed includes copper metal and metal oxides of at least lithium and nickel.

[0089] The method includes an initial leaching step in which lithium-ion battery waste (which may be mixed with other electronic waste sources) is subjected to alkaline leaching with a first leach solution containing ammonium sulfate. In this particular embodiment, the first leach solution additionally contains ammonia, which has been found to enhance the leaching process by promoting the formation of stable soluble Ni and Co complexes. Leaching is carried out at atmospheric pressure and ambient temperature. However, leaching may also be carried out at elevated temperatures, for example, at temperatures below the boiling point of the leach solution.

[0090] The alkaline leaching oxidizes elemental copper contained within the lithium-ion battery to soluble copper ions, thus providing a source of electrons to reduce or otherwise liberate nickel and lithium ions contained within the battery. Leaching thus results in the formation of a first leachate containing soluble copper, lithium, and nickel ions, and a first solid residue.

[0091] The first leachate is then separated from the first solid residue.

[0092] The first solid residue contains low-value materials such as iron and aluminum, but depending on the type of lithium-ion battery waste, may also contain residual lithium and nickel compounds.

[0093] The amount of lithium and nickel may be sufficient to warrant further processing for the recovery of these metals. If so, the first solid residue may be subjected to a further leaching step with a second leach solution containing ammonium sulfate and preferably ammonium chloride. The inventors have found that ammonium chloride advantageously stabilizes the Cu(I) ions. The second leach is carried out at atmospheric pressure and ambient temperature. However, as noted above, the second leach may also be carried out at elevated temperatures, e.g., below the boiling point of the leach solution. The second leach may be an oxidative leach. That is, an oxidizing agent, such as air, hydrogen peroxide, or hypochlorite, may be used during leaching to aid in the recovery of the metals. When the redox half-cell potential is less than 100 mV, as is typically the case for LFP battery waste feeds, the oxidizing agent is useful to assist or enhance the leaching process.

[0094] The second leach provides a second leach solution containing soluble ions of lithium and nickel, and a second solid residue.

[0095] The second leachate is then separated from the second solid residue.

[0096] The first and second leach solutions are then combined to form a combined leach solution, which can then be subjected to several steps for the selective recovery of copper, lithium, and nickel.

[0097] The combined leachate can be subjected to a solvent extraction process for extraction of copper and / or nickel. In an alternative embodiment in which the leachate contains Mn ions, the leachate is first subjected to treatment to remove Mn, for example, by an oxidation and precipitation process as generally described above. Additionally, in embodiments in which the leachate contains Co ions, the leachate is first subjected to an oxidation process (e.g., during Mn recovery) to convert the Co ions to Co(III) to prevent the solvent extractant from being poisoned by the Co ions. In either case, the copper- and / or nickel-loaded solvent can then be separated from the combined leachate, and the copper and / or nickel are then recovered from the solvent. Copper and nickel can be recovered from the solvent via stripping with a stripping agent such as sulfuric acid. Generally, nickel can be selectively stripped at a lower residual acid concentration than copper, for example, in the pH range of about 1 to 4, and copper is then stripped by increasing the acid concentration, for example, to above about 50 g / L H2SO4. This two-stage stripping allows for selective separation of copper and nickel.

[0098] The combined leachate, from which copper and nickel have been substantially removed, may be further processed to recover ammonia, ammonium salts, and lithium.

[0099] Ammonia is steam stripped from the leachate, and the recovered ammonia is recycled and reused as a component of the first leach solution. The lithium in the leachate is generally in the form of lithium sulfate. This lithium sulfate can be crystallized with ammonium sulfate (e.g., via an evaporation process) in the form of lithium ammonium sulfate and separated from the leachate. The lithium ammonium sulfate can then be subjected to thermal treatment to decompose the lithium ammonium sulfate into lithium sulfate solids, ammonia gas, and sulfur trioxide gas. The ammonia and sulfur trioxide gas can be captured and reacted with water, such as in a wet scrubber, to form ammonium sulfate, which can then be recycled to the first and / or second leach steps.

[0100] Figure 1 is a process flow diagram illustrating a method according to the above-described embodiment. The method of Figure 1 describes the recovery of a copper product 18 and a lithium product 30. In this embodiment, feed stream 1 is subjected to a pretreatment process, such as shredding 100, to make it suitable for further processing, typically <5 mm. The resulting shredded feed stream 2 is then passed to an alkaline leaching circuit 110, where it is contacted with a liquor containing ammonia, ammonium sulfate with or without ammonium chloride 19, and ammonia supplements 3 and 22 to solubilize the copper. The alkaline leaching circuit is operated, for example, at about 50°C, atmospheric pressure, about pH 9.0, and about 10% solids. The resulting alkaline leaching slurry 4 is subjected to a solid-liquid separation step 120, such as one or more thickeners with washes, and the ammoniacal leach solution 6 is sent to a solvent extraction circuit 160.

[0101] The thickener underflow 5 is sent to the ammonium sulfate leach circuit 130 where it contacts a solution containing ammonium sulfate 24 and 32 and ammonium sulfate make-up 7. Air 8 is sparged into the leach circuit 130. The ammonium sulfate leach is operated at about 100°C, about Eh 120 mV (Ag / AgCl electrode), and about 10% solids. The ammonium sulfate leach effluent 9 is sent to the thickener 140. The thickener underflow 11 is sent to the filter 150, which filters the concentrated slurry. The resulting filter cake is washed with water 12, and the filtrate and wash filtrate are combined with the thickener overflow 10 and the ammonia leach 6.

[0102] The pregnant leach solution is sent to a copper solvent extraction circuit 160 where it is contacted with a copper extractant, such as a commercially available oxime extractant, e.g., LIX84I™. Copper is loaded onto the copper extractant, and the loaded extractant 14 is separated from the raffinate 19. The loaded extractant 14 is contacted with dilute sulfuric acid 16 or anolyte from the copper electrowinning stage 180 in a copper strip stage 170 to produce a loaded strip solution 15 containing copper and copper-depleted extractant. Stripped organics (not shown) are recycled to the extraction circuit 160 to extract more copper (not shown). Copper product 18 is recovered from the copper-loaded strip solution 15 in the copper electrowinning stage 180.

[0103] The copper-depleted raffinate 19, which contains ammonia and ammonium sulfate, is sent to an ammonia leach circuit 110 to recover more metals. The remaining filtrate 29 is sent to an ammonia recovery circuit 190, where steam 21 is used to strip the ammonia 22. The recovered ammonia 22 is reused in the process, specifically, for example, in the ammonia leach 110.

[0104] The ammonia-free liquor 24 is sent to the ammonium sulfate leach 130 and then to the crystallizer 200 where the condensate 25 is removed by forced evaporation and lithium ammonium sulfate 26 is crystallized. The crystallizer effluent is subjected to solid-liquid separation using a centrifuge 210 and the centrate 27 is sent to the ammonium sulfate leach 130. The lithium ammonium sulfate 28 is subjected to calcination in a kiln 220 where the solid lithium sulfate 30 is collected for sale and the off-gas 29 is collected in a wet scrubber using scrub water 31 to recover ammonium sulfate solution 32 which is sent to the ammonium sulfate leach 130.

[0105] Embodiment 3. The present embodiment describes a method for recovering metals from a feed containing one or more lithium-ion battery types. In this particular embodiment, the feed includes copper metal and metal oxides of at least cobalt, lithium, manganese, and nickel.

[0106] The method includes an initial leaching step in which lithium-ion battery waste (which may be mixed with other electronic waste sources) is subjected to alkaline leaching with a first leaching solution containing ammonium sulfate. In this particular embodiment, the first leaching solution additionally contains ammonia, which has been found to enhance the leaching process, as described above. Leaching is carried out at atmospheric pressure and ambient temperature. However, leaching may also be carried out at elevated temperatures, for example, at temperatures below the boiling point of the leaching solution.

[0107] The alkaline leaching oxidizes elemental copper contained in lithium-ion batteries to soluble copper ions and reduces or otherwise liberates nickel, cobalt, manganese, and lithium ions contained in, for example, nickel manganese cobalt (NMC), lithium cobalt oxide (LCO), and lithium manganese oxide (LMO) batteries. Thus, leaching results in the formation of a first leachate containing soluble ions of cobalt, copper, lithium, manganese, and nickel, and a first solid residue.

[0108] The first leachate is then separated from the first solid residue.

[0109] The first solid residue contains low-value materials such as iron and aluminum, but depending on the type of lithium-ion battery waste, may also contain residual cobalt, lithium, manganese, and nickel compounds. For example, if the feed contains lithium iron phosphate (LFP) and lithium nickel cobalt aluminum oxide (NCA) batteries, some of the cobalt, lithium, and nickel will be retained in the first solid residue.

[0110] The amounts of cobalt, lithium, manganese, and nickel may be sufficient to make further recovery of these metals economically viable and therefore desirable. If so, the first solid residue may be subjected to a further leaching step with a second leach solution containing ammonium sulfate and preferably ammonium chloride. The second leach is conducted at atmospheric pressure and ambient temperature. However, as noted above, the second leach may also be conducted at elevated temperatures, e.g., temperatures below the boiling point of the leach solution. The second leach may be an oxidative leach. That is, an oxidizing agent, such as air, hydrogen peroxide, or hypochlorite, may be used during leaching to aid in metal recovery. Generally, in feeds containing NCA and / or NMC battery materials, oxidizing agents are not required because cobalt, nickel, and manganese are present in sufficient amounts to provide a sufficiently high redox half-cell potential of >100 mV. However, if the redox half-cell potential is less than 100 mV (e.g., typically the case with LFP battery waste feeds), an oxidizing agent may be useful to assist or enhance the leaching process.

[0111] The second leach provides a second leach solution containing soluble ions of cobalt, lithium, manganese, and nickel, and a second solid residue.

[0112] The second leachate is then separated from the second solid residue. As noted above, depending on the type of battery present, the second solid residue may contain commercially recoverable amounts of residual cobalt, lithium, manganese, and nickel.

[0113] To further recover these metals, the second solid residue is subjected to a size separation process to classify the first solid residue into a coarse fraction and a fine fraction. The fine fraction contains >80% residual nickel, and also contains some residual cobalt, lithium, and manganese. The fine fraction is subjected to acid leaching, such as with sulfuric acid, to provide a third leach solution containing cobalt, lithium, manganese, and nickel ions, and a third solid residue. The third leach is conducted at atmospheric pressure and ambient temperature. However, as noted above, the third leach may also be conducted at elevated temperatures, for example, below the boiling point of the leach solution.

[0114] The third leachate is then separated from the third solid residue.

[0115] It will be appreciated that in an alternative embodiment, the third acid leaching step is omitted.

[0116] Aluminum, iron, and phosphate are not extracted to significant amounts and are generally retained in the primary, secondary, and / or tertiary solid residues. With this in mind, the leaching process is selective for more expensive metals such as copper, cobalt, lithium, manganese, and nickel.

[0117] The first, second, and third leach solutions may then be combined to form a combined leach solution, which may then be subjected to several steps for the selective recovery of cobalt, copper, lithium, manganese, and nickel.

[0118] To recover the manganese, the combined leachate is subjected to an oxidation step in the presence of ammonia to precipitate manganese in the form of manganese oxides, such as MnO, MnO, and / or MnO (but not MnO). The inventors have found that when the leachate additionally contains cobalt ions, the presence of ammonia is important to complex the cobalt ions and retain them in the form of soluble Co(III) ions, preventing the formation of a CoO precipitate. The manganese oxide precipitate can then be recovered from the combined leachate using any solid-liquid separation process commonly known to those skilled in the art, such as filtration.

[0119] The combined leachate can then be subjected to a solvent extraction process for the extraction of copper and / or nickel. The copper- and / or nickel-loaded solvent can then be separated from the combined leachate, and the copper and / or nickel are then recovered from the solvent. Copper and nickel can be recovered from the solvent via stripping with a stripping agent such as sulfuric acid. Generally, nickel can be selectively stripped at a lower residual acid concentration than copper, for example, in the pH range of about 1 to 4, and copper is then stripped by increasing the acid concentration, for example, to above about 50 g / L H2SO4. This two-stage stripping allows for the selective separation of copper and nickel.

[0120] In an alternative embodiment, Cu and Ni can be recovered before Mn recovery.

[0121] The combined leachate can then be subjected to further processing to recover the cobalt. In this embodiment, the cobalt is recovered via a cobalt precipitation process, whereby the combined leachate is treated with hydrogen sulfide gas or a sulfide, such as ammonium sulfide, to precipitate cobalt sulfide. The cobalt sulfide can then be recovered from the combined leachate using any solid-liquid separation process commonly known to those skilled in the art, such as filtration.

[0122] The combined leachate, now substantially depleted of cobalt, copper, manganese, and nickel, can be further processed to recover ammonia, ammonium salts, and lithium.

[0123] Ammonia is steam stripped from the leachate, and the recovered ammonia is recycled and reused as a component of the first leach solution. The lithium in the leachate is generally in the form of lithium sulfate. This lithium sulfate can be crystallized with ammonium sulfate (e.g., via an evaporation process) in the form of lithium ammonium sulfate and separated from the leachate. The lithium ammonium sulfate can then be subjected to thermal treatment to decompose the lithium ammonium sulfate into lithium sulfate solids, ammonia gas, and sulfur trioxide gas. The ammonia and sulfur trioxide gas can be captured and reacted with water, such as in a wet scrubber, to form ammonium sulfate, which can then be recycled to the first and / or second leach steps.

[0124] The process is described in more detail with reference to Figure 2. Figure 2 is a process flow diagram illustrating the method of the present invention generally according to the embodiment described above.

[0125] The process of Figure 2 describes the recovery of nickel product 27, copper product 32, cobalt product 37, and lithium product 48. In this embodiment, feed stream 1 is subjected to a pretreatment process, such as shredding 100 mm to <5 mm, e.g., <1 mm, to make feed stream 1 suitable for further processing. The resulting shredded feed stream 2 is then passed to alkaline leaching circuit 110, where it is contacted with a liquid containing ammonia, ammonium sulfate with or without ammonium chloride 39, and ammonia supplements 3 and 40 to solubilize the metal species. Conditions within alkaline leaching circuit 110 include about 5-10% solids, about 50°C, atmospheric pressure, about 12 hours residence time, a pH of about 9 with ammonia, about 200 g / L ammonium sulfate, and, if present, about 20 g / L ammonium chloride.

[0126] The resulting alkaline leach slurry 4 is subjected to a solid-liquid separation step 120 such as one or more thickeners with washing, and the ammoniacal leachate 6 is sent to a manganese oxide precipitation circuit 180 .

[0127] The thickener underflow 5 is sent to the ammonium sulfate leach circuit 130 where it is contacted with a solution containing ammonium sulfate 47 and ammonium sulfate make-up 7. Conditions in the ammonium sulfate leach circuit 130 include about 5-10% solids, about 100-105°C, atmospheric pressure, a residence time of about 4-12 hours, about 200 g / L ammonium sulfate and 20 g / L ammonium chloride.

[0128] The ammonium sulfate leach effluent 8 is directed through a screen 140, e.g., between 75 and 500 μm, e.g., about 180 μm, to separate coarse and fine particle fractions. The coarse fraction 9 is stored and the fine fraction 10 is sent to a thickener 150. The thickener overflow, e.g., ammonium sulfate leach liquor 11, is sent to a manganese oxide precipitation circuit 180.

[0129] The thickener underflow 12 is sent to an acid leaching circuit 160 where it is contacted with sulfuric acid 13. The conditions in the acid leaching circuit 160 included a temperature in the range of about 20-100°C, e.g., 70°C, a pH of less than about 3, e.g., a pH of about 1.5, a residence time of about 4-12 hours, a solids content of 30%, and an acid loading of 98%.

[0130] The acid leach effluent 14 is subjected to filtration 170 and the solids are washed to produce a leach residue 15 (which is stored) and an acid leach liquor 17 (which is sent to a manganese oxide precipitation circuit 180).

[0131] The leach solutions 6, 11 and 17 are sent to a manganese oxide precipitation circuit 180 where air 18 is sparged through the solution to force the precipitation of manganese oxide. The precipitated slurry 19 is separated into solids and liquids by thickening filtration 190. The manganese product 20 is washed and stored.

[0132] The pregnant leach solution after manganese precipitation 21 is sent to a copper and nickel solvent extraction circuit 200, where it is contacted with a copper and nickel extractant, such as a commercially available oxime extractant, e.g., LIX84I™. The copper and nickel are loaded into the copper extractant, and the loaded extractant 23 is separated from the raffinate 22. The loaded extractant 23 is contacted with dilute sulfuric acid 24, e.g., 150 g / L sulfuric acid, in a nickel stripping stage 210 to produce a nickel-containing loaded stripping solution 25 and a nickel-depleted extractant 28. The nickel-depleted extractant 28 is contacted with dilute sulfuric acid liquor 29, e.g., 200 g / L sulfuric acid, in a copper stripping stage 220 to produce a copper-containing loaded strip solution 30. The stripped organics (not shown) are recycled to the extraction circuit 200 (not shown) to extract more copper and nickel. A nickel product 27 (ostensibly in the form of nickel sulfate) is recovered from the nickel-loaded strip solution 25 in a nickel crystallization stage 230. A copper product 32 (ostensibly in the form of copper sulfate) is recovered from the copper-loaded strip solution 30 in a copper electrowinning stage 240.

[0133] The copper and nickel depleted raffinate 22 is sent to a cobalt recovery circuit 250 where a precipitation reagent, such as hydrogen sulfide gas 33, is added to force the precipitation of cobalt sulfide. The resulting slurry 34 is subjected to solid-liquid separation, such as by thickener and filter 260, and washed with water 35 to produce a cobalt product 37.

[0134] The majority of the resulting filtrate 39, which contains ammonia and ammonium sulfate, is sent to the ammonia leaching circuit 110 for more metal recovery. The remaining filtrate 38 is sent to the ammonia recovery circuit 270, where steam 41 is used to strip the ammonia 40. The recovered ammonia 40 is reused in the process, specifically, for example, in the ammonia leaching 110.

[0135] The ammonia-free liquor 42 is sent to the ammonium sulfate leach 130 and further to the crystallizer 280 where the condensate 43 is removed by forced evaporation and lithium ammonium sulfate 46 is crystallized. The crystallizer effluent is subjected to solid-liquid separation using a centrifuge 290 and the centrate 45 is sent to the ammonium sulfate leach 130. The lithium ammonium sulfate intermediate 46 is subjected to calcination in a kiln 300 where the solid, lithium sulfate 48, is collected for sale and the off-gas 47 is collected in a wet scrubber using scrub water 49 to recover the ammonium sulfate solution 50. [Example]

[0136] Example 1 This example reports the single-step alkaline leaching of raw lithium-ion nickel manganese cobalt 622 (NMC622) battery fragments with a leach solution of ammonium sulfate, ammonia, and ammonium chloride.

[0137] The NMC battery fragments contained, on an elemental basis, 22.9 wt% Cu, 12.5 wt% Ni, 4.9 wt% Co, 6.2 wt% Mn, and 2.94 wt% Li. Elemental copper was present in sufficient amount to provide a redox potential of less than −150 mV (Ag / AgCl electrode) during leaching.

[0138] NMC battery fragments were reacted with an aqueous leach solution containing 169 g / L ammonium sulfate, 46 g / L ammonia, and 14.5 g / L ammonium chloride at a solids loading of 3.8 wt %. Leaching was carried out at a pH of 9.5, atmospheric pressure, and a temperature of 50°C for 2 hours.

[0139] The extraction of nickel, cobalt, copper, lithium and manganese into the leachate was found to be 97.5%, 96.4%, 99.3%, 95.5% and 96.1%, respectively.

[0140] Although not reported in this example, nickel, cobalt, copper, lithium, and manganese can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonium sulfate, ammonia, and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0141] Example 2 This example reports the three-stage leaching of a mixed feed of raw lithium-ion nickel manganese cobalt 622 (NMC622), lithium-ion nickel manganese cobalt 811 (NMC811), lithium nickel cobalt aluminum oxide (NCA), and lithium iron phosphate (LFP) battery fragments with a leach solution of ammonium sulfate, ammonia, and ammonium chloride.

[0142] An equal weight mixture of NMC811, NMC622, NCA, and LFP battery fragments was prepared containing 7.01 wt% Cu, 14.5 wt% Ni, 2.48 wt% Co, 2.16 wt% Mn, and 2.69 wt% Li. Elemental copper was present in an amount sufficient to provide a redox potential of less than −150 mV (Ag / AgCl electrode) during leaching.

[0143] The battery fragment mixture was first subjected to alkaline leaching at a loading of 9.8 wt.% solids in a solution containing 215 g / L ammonium sulfate, 105 g / L ammonia, and 21 g / L ammonium chloride. Leaching was carried out at a pH range of 9.4-9.9, atmospheric pressure, and a temperature of 50°C for 6 hours.

[0144] The extraction of nickel, cobalt, copper, lithium and manganese into the leachate was 37.6%, 57.6%, 81.5%, 47.8% and 67.9%, respectively. The metals were extracted mainly from NMC622 and NMC811 batteries.

[0145] The solid residue from the first leach was found to contain 1.46 wt% Cu, 10.2 wt% Ni, 1.19 wt% Co, 0.78 wt% Mn and 1.59 wt% Li.

[0146] This solid residue was separated from the leachate and subjected to a second leach at a loading of 6.9 wt.% solids using a solution containing 343 g / L ammonium sulfate and 34 g / L ammonium chloride. Leaching was carried out in a solution with a natural pH in the range of 5.1-5.3 and a natural redox potential of 165 mV (Ag / AgCl electrode). Leaching was carried out at atmospheric pressure and a temperature of 100°C for 6 hours.

[0147] The extraction of nickel, cobalt, copper, lithium and manganese reached 59.4%, 82.2%, 33.8%, 94.3% and 94.7%, respectively. Metals except nickel were extracted from all battery types. Nickel was extracted mainly from NMC811 and NMC622 materials that were not leached in the preceding alkaline leaching.

[0148] The extraction of nickel, cobalt, copper, lithium and manganese in the leachate over both leaching stages reached 74.7%, 92.5%, 87.7%, 97.0% and 98.3%, respectively.

[0149] The solid residue from the second leach was first screened at 180 microns to remove coarse material, particularly steel and aluminum foil. The screen undersize contained 1.27 wt% Cu, 5.44 wt% Ni, 0.28 wt% Co, 0.95 wt% Mn and 0.12 wt% Li.

[0150] The solid residue was repulped in water to 30% solids, and then sulfuric acid was added to a target pH of 1.50. After leaching for 6 hours at 70°C, extractions of nickel, cobalt, copper, lithium, and manganese reached 99.5%, 99.0%, 98.8%, 96.3%, and 92.6%, respectively. Acid consumption was significantly lower (<200 kg / t) than a comparable sulfuric acid-only flowsheet (>1200 kg / t).

[0151] Extraction of nickel, cobalt, copper, lithium and manganese into the leach solution reached 96.8%, 98.2%, 97.7%, 98.6% and 93.0%, respectively, across all three leaching stages, including metal losses associated with screening.

[0152] The leachates from the three leaching steps can be combined and subsequently processed for the selective recovery of nickel, cobalt, copper, lithium, and manganese using the methods disclosed herein. Similarly, ammonium sulfate, ammonia, and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0153] Example 3 This example reports the oxidative leaching of raw lithium iron phosphate (LFP) battery fragments using a one-step aqueous leaching solution of ammonium sulfate and ammonium chloride.

[0154] The LFP battery fragments contained 6.7 wt% Cu and 1.99 wt% Li on an elemental basis.

[0155] LFP battery fragments were reacted with an aqueous leach solution containing 350 g / L ammonium sulfate and 17.7 g / L ammonium chloride at a loading of 4.0 wt% solids. Air was added as an oxidant to a target redox potential of +150 mV (Ag / AgCl electrode).

[0156] Leaching was carried out at natural pH ranging from 4.9 to 5.2, atmospheric pressure and a temperature of 100°C for 4 hours.

[0157] The extraction of copper and lithium into the leachate was found to be 83.4% and 92.5%, respectively. Only 0.5% of Fe was co-extracted.

[0158] Although not reported in this example, copper and lithium can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0159] Example 4 This example reports the leaching of raw lithium-ion nickel manganese cobalt 811 (NMC811) battery fragments using a one-step aqueous leaching solution of ammonium sulfate and ammonium chloride.

[0160] The NMC811 battery fragments contained, on an elemental basis, 2.46 wt % Cu, 22.2 wt % Ni, 2.72 wt % Co, 1.72 wt % Mn, and 2.83 wt % Li.

[0161] NMC811 battery fragments were reacted with an aqueous leach solution containing 355 g / L ammonium sulfate and 17.7 g / L ammonium chloride at a loading of 4.0 wt % solids. Additional copper metal was added in an amount of 250 kg / t, which could be introduced in the form of scrap electronics, such as printed circuit boards.

[0162] Leaching was carried out at a natural pH ranging from 4.7 to 5.5, a natural redox potential of about 15 to 150 mV (Ag / AgCl electrode), atmospheric pressure, and a temperature of 100°C for 4 hours.

[0163] The extraction of copper, nickel, cobalt, manganese and lithium into the leachate was 60.1%, 67.0%, 79.3%, 94.8% and 95.5%, respectively.

[0164] Although not reported in this example, copper, nickel, cobalt, manganese, and lithium can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0165] Example 5 This example reports the leaching of raw lithium nickel cobalt aluminum oxide (NCA) battery fragments with a single-step aqueous leaching solution of ammonium sulfate and ammonium chloride.

[0166] The NCA battery fragments contained, on an elemental basis, 0.95 wt % Cu, 24.3 wt % Ni, 2.77 wt % Co, 0.02 wt % Mn, and 3.20 wt % Lion.

[0167] NCA battery fragments were reacted with an aqueous leach solution containing 355 g / L ammonium sulfate and 17.7 g / L ammonium chloride at a loading of 4.0 wt% solids. Additional copper metal was added in an amount of 250 kg / t, which could be introduced in the form of scrap electronics, such as printed circuit boards.

[0168] Leaching was carried out at a natural pH ranging from 4.5 to 4.9, a natural redox potential of approximately −16 to 30 mV (Ag / AgCl electrode), atmospheric pressure, and a temperature of 100°C for 4 hours.

[0169] The extraction of copper, nickel, cobalt, manganese and lithium into the leachate was 87%, 33.4%, 58.9%, 58.2% and 94.6%, respectively.

[0170] Although not reported in this example, copper, nickel, cobalt, manganese, and lithium can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0171] Example 6 This example reports the alkaline leaching of raw lithium-ion manganese oxide (LMO) battery fragments using a one-step aqueous leaching solution of ammonia, ammonium sulfate, and ammonium chloride.

[0172] The LMO battery pieces contained, on an elemental basis, 3.28 wt% Cu, 3.65 wt% Ni, 1.24 wt% Co, 27.9 wt% Mn, and 2.52 wt% Li.

[0173] LMO battery fragments were reacted with an aqueous leach solution containing 45 g / L ammonia, 180 g / L ammonium sulfate, and 18 g / L ammonium chloride at a loading of 4.0 wt% solids. Additional copper metal was added in an amount of 250 kg / t, which could be introduced in the form of scrap electronics, such as printed circuit boards.

[0174] Leaching was carried out at a natural pH ranging from 8.8 to 9.1, a redox potential of approximately −123 to −250 mV (Ag / AgCl electrode), atmospheric pressure, and a temperature of 50°C for 4 hours.

[0175] The extraction of copper, nickel, cobalt, manganese and lithium into the leachate was 84.0%, 89.7%, 93.3%, 71.8% and 97.3%, respectively.

[0176] Although not reported in this example, copper, nickel, cobalt, manganese, and lithium can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonia, ammonium sulfate, and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0177] Example 7 This example reports the alkaline leaching of raw lithium cobalt oxide (LCO) battery fragments using a single-step aqueous leaching solution of ammonia, ammonium sulfate, and ammonium chloride.

[0178] The LCO battery fragments contained, on an elemental basis, 5.42 wt % Cu, 28.6 wt % Co, and 3.46 wt % Li.

[0179] LCO battery fragments were reacted with an aqueous leach solution containing 45 g / L ammonia, 180 g / L ammonium sulfate, and 18 g / L ammonium chloride at a loading of 4.0 wt % solids.

[0180] Leaching was carried out for 2 hours at a natural pH of 9.2, a redox potential of -150 mV (Ag / AgCl electrode), atmospheric pressure, and a temperature of 50°C. After 2 hours, the extraction rates of copper, cobalt, and lithium into the leachate were 93.8%, 24.1%, and 25.9%, respectively.

[0181] 100 kg / t copper was then added and leaching was carried out for a further 2 hours. After a further 2 hours of leaching, the extraction of copper, cobalt and lithium into the leachate reached 97.6%, 67.5% and 68.9%, respectively.

[0182] This example demonstrates that the addition of copper results in higher metal extraction.

[0183] Although not reported in this example, copper, cobalt, and lithium can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonia, ammonium sulfate, and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0184] Example 8 This example reports the three-stage leaching of a mixed feed of raw lithium-ion nickel manganese cobalt 622 (NMC622), lithium-ion nickel manganese cobalt 811 (NMC811), lithium nickel cobalt aluminum oxide (NCA), and lithium iron phosphate (LFP) battery fragments with a leach solution of ammonium sulfate and ammonia. No ammonium chloride was added.

[0185] An equal weight mixture of NMC811, NMC622, NCA, and LFP battery fragments containing 7.01% Cu, 14.5% Ni, 2.48% Co, 2.16% Mn, and 2.69% Li was reacted in a solution containing 220 g / L ammonium sulfate and 110 g / L ammonia at 9.1% solids and 50°C. After 6 h of leaching at pH 9.5-9.9 and a redox potential below -90 mV (Ag / AgCl electrode), extractions of nickel, cobalt, copper, lithium, and manganese reached 58.8%, 45.8%, 49.4%, 47.4%, and 78.3%, respectively. Metals were extracted primarily from NMC622 and NMC811 batteries.

[0186] The solid residue from the first leach was found to contain 6.17% Cu, 8.55% Ni, 0.468% Co, 0.67% Mn and 2.10% Li.

[0187] This solid residue was reacted in a solution containing 354 g / L ammonium sulfate at 5.1% and 100°C. After 6 hours of leaching at a natural pH of 4.2-5.4 and a natural redox potential of 360-530 mV (Ag / AgCl electrode), the extractions of nickel, cobalt, copper, lithium, and manganese reached 15.1%, 77.6%, 67.7%, 75.5%, and 8.5%, respectively. Metals except nickel were extracted from all battery types. Nickel was extracted primarily from the NMC811 and NMC622 materials, which were not leached in the primary leaching.

[0188] The extraction of nickel, cobalt, copper, lithium and manganese over both leaching stages amounted to 64.5%, 85.5%, 87.5%, 86.1% and 79.8%, respectively.

[0189] The solid residue from the second leach was first screened at 180 microns to remove coarse material, particularly steel and aluminum foil, and the screen undersize contained 1.61% Cu, 8.2% Ni, 0.49% Co, 0.69% Mn, and 0.59% Li.

[0190] The solid residue was repulped in water to 30% solids, and then sulfuric acid was added to a target pH of 1.90. After leaching for 6 hours at 70°C, extractions of nickel, cobalt, copper, lithium, and manganese reached 58.9%, 98.3%, 37.1%, 64.9%, and 7.0%, respectively. Acid consumption was significantly lower (<100 kg / t) than a comparable sulfuric acid-only flowsheet (>1200 kg / t). Higher metal extractions are expected with higher acid loadings.

[0191] The extraction of nickel, cobalt, copper, lithium and manganese across all three leaching stages reached 85.7%, 92.3%, 99.7%, 95.5% and 80.0%, respectively, including metal losses associated with screening.

[0192] Example 9 This example reports the leaching of a mixture of lithium iron phosphate (LFP) and nickel cobalt aluminum (NCA) battery fragments in a 4:1 NCA mass ratio using a single-stage aqueous leaching solution of ammonium sulfate and ammonium chloride.

[0193] The battery pieces contained, on an elemental basis, 0.26 wt % Cu, 4.39 wt % Ni, 0.50 wt % Co, 19.0 wt % Fe, and 1.99 wt % Li.

[0194] The battery pieces were reacted with an aqueous leach solution containing 230 g / L ammonium sulfate, 23 g / L ammonium chloride, and 5.5 g / L Cu (as copper sulfate) at a loading of 4.9 wt% solids. The copper sulfate was added due to the low copper grade of the battery pieces.

[0195] Leaching was carried out at a natural pH ranging from 4.80 to 5.13, a redox potential of +123 to +180 mV (Ag / AgCl electrode), atmospheric pressure, and a temperature of 100 °C for 8 h.

[0196] The extraction of nickel, cobalt, iron and lithium into the leachate was 44.0%, 75.7%, 0.43% and 94.7%, respectively.

[0197] Although not reported in this example, copper, nickel, cobalt, and lithium can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0198] Example 10 This example reports the leaching of a mixture of lithium iron phosphate (LFP) and nickel cobalt aluminum (NCA) battery fragments in LFP. A one-stage aqueous leaching solution of ammonium sulfate was used with a 4:1 NCA mass ratio. No ammonium chloride was added to the leaching.

[0199] The battery pieces contained, on an elemental basis, 0.26 wt % Cu, 4.39 wt % Ni, 0.50 wt % Co, 19.0 wt % Fe, and 1.99 wt % Li.

[0200] The battery pieces were reacted with an aqueous leach solution containing 230 g / L ammonium sulfate and 5.5 g / L Cu (as copper sulfate) at a loading of 4.9 wt% solids. The copper sulfate was added due to the low copper grade of the battery pieces.

[0201] Leaching was carried out at a natural pH ranging from 4.22 to 5.05, a redox potential of +91 to +126 mV (Ag / AgCl electrode), atmospheric pressure, and a temperature of 100°C for 8 h.

[0202] The extraction of nickel, cobalt, iron and lithium into the leachate was 20.5%, 43.4%, 0.26% and 81.6%, respectively.

[0203] Although not reported in this example, copper, nickel, cobalt, manganese, and lithium can be selectively recovered from the leachate using the methods disclosed herein. Similarly, ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0204] It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or apparent from the text or drawings, all of these different combinations constituting various alternative aspects of the invention.

Claims

1. 1. A method for recovering metals from electronic waste or leaching residues thereof, wherein the electronic waste or leaching residues comprise elemental copper and one or more lithium compounds, the method comprising: leaching the electronic waste or leach residue with a leach solution comprising ammonium sulfate in the presence of an oxidizing agent to provide a leach solution and a solid residue comprising Cu and Li ions; and separating said leachate and said solid residue.

2. 2. The method of claim 1, wherein the elemental copper is present in an amount sufficient to provide a redox potential of −100 mV or less as determined using an Ag / AgCl reference electrode, and preferably the redox potential is −150 mV or less.

3. 3. The method of claim 1 or 2, wherein the oxidizing agent is present in an amount sufficient to provide a redox potential of +50 mV or greater as determined using an Ag / AgCl reference electrode, preferably +100 mV or greater, more preferably +150 mV or greater.

4. 4. The method according to any one of claims 1 to 3, wherein the temperature is from about 0°C up to the boiling point of the leaching solution at the operating conditions of the leaching, preferably the temperature is from about 40°C.

5. A method according to any one of claims 1 to 4, wherein the leaching is carried out at atmospheric pressure.

6. 6. The method of any one of claims 1 to 5, wherein the leaching is carried out for up to 24 hours, preferably up to 18 hours, more preferably up to 12 hours, most preferably up to 8 hours, additionally or alternatively for at least 0.5 hours, preferably at least 1 hour, more preferably at least 1.5 hours, most preferably at least 2 hours.

7. The method of any one of claims 1 to 6, wherein the method further comprises recovering Cu ions from the leachate.

8. After recovering Cu ions from the leachate, the method further comprises: crystallizing ammonium lithium sulfate from the leachate; 8. The method of claim 7, further comprising thermally decomposing the crystallized lithium ammonium sulfate to form gases comprising ammonia and sulfur oxides and solid lithium sulfate.

9. 9. The method of any one of claims 1 to 8, wherein prior to the step of crystallizing the lithium ammonium sulfate, the leach solution is an ammonia, Cu, Ni, Co, Mn dilute leach solution and / or the leach solution is treated so that it is substantially free of ammonia, Al, Cu, Fe, Ni, Co, or Mn.

10. 10. The method of claim 1, wherein the electronic waste further comprises one or more transition metals, the oxidizing agent is an oxide of the one or more transition metals, and the leachate comprises ions of the one or more transition metals.

11. 11. The method of claim 10, wherein the one or more transition metals are selected from the group consisting of Co, Mn, and / or Ni.

12. 12. The method of any one of claims 1 to 11, wherein the electronic waste further comprises Ni, and the leach solution further comprises ammonia in an amount such that the pH of the leach solution is from about 8.5 to about 10.5, and the leach solution comprises at least Cu, Li, and Ni ions.

13. 13. The method of claim 12, wherein the leach solution comprises ammonia and ammonium sulfate in a ratio of about 1:2 to about 1:

20.

14. 14. The method of claim 12 or 13, wherein the method further comprises simultaneously recovering Cu and Ni ions from the leach solution via a solvent extraction process.

15. 12. The method of any one of claims 1 to 11, wherein the electronic waste further comprises Co, and the leach solution further comprises ammonia in an amount such that the pH of the leach solution is from about 8.5 to about 10.5, and the leach solution comprises at least Cu, Li, and Co ions.

16. 16. The method of claim 15, wherein the method further comprises recovering Cu ions from the leachate and precipitating Co from the leachate after removal of Cu ions.

17. 17. The method of claim 16, wherein precipitating Co from the leach solution comprises precipitating cobalt sulfide from the leach solution.

18. The electronic waste further comprises Mn, the leachate further comprises a leachate containing Mn ions, and the method further comprises: treating the leachate with an oxidizing agent to form a precipitate of Mn and provide a Mn-dilute leachate containing Cu and Li ions; and separating the precipitate of Mn from the Mn-dilute leach solution.

19. 20. The method of claim 18, wherein the oxidant is air.

20. 20. The method of any one of claims 1 to 19, wherein the electronic waste further comprises Fe and Al, the solid residue comprises Fe and Al, the leachate is an Fe-, Al-dilute leachate, and / or the leachate is substantially free of Fe or Al.

21. the electronic waste comprises elemental copper and one or more compounds of Co, Li, and Ni, the leach solution further comprises ammonia, the leachate comprises Co ions, Cu ions, Li ions, and Ni ions, and after the step of separating the leachate from the solid residue, the method further comprises subjecting the leachate to a solvent extraction step to remove Cu and Ni ions from the leachate to form a Cu, Ni-dilute leachate; subjecting the Cu,Ni-dilute leachate to a precipitation step to remove Co ions from the Cu,Ni-dilute leachate to form a Co,Cu,Ni-dilute leachate; and recovering Li from the dilute Co-, Cu-, Ni- leachate; 2. The method of claim 1, wherein prior to the step of recovering Li, the leach solution is subjected to an ammonia recovery step such that the Co-, Cu-, Ni-dilute leach solution is substantially free of ammonia during recovery of Li.

22. The Co ions are Co ２＋ ions, and prior to subjecting the leachate to the solvent extraction step, the method further comprises treating the leachate with an oxidizing agent to remove the Co ions. ２＋ ions to Co ３＋ 22. The method of claim 21, further comprising oxidizing to ions.

23. wherein the electronic waste comprises elemental copper and one or more compounds of Co, Li, Mn, and Ni, and the leach solution further comprises ammonia, the leach solution comprising Co ions, Cu ions, Li ions, Mn ions, and Ni ions, and after the step of separating the leach solution from the solid residue, the method further comprises: The leachate is treated with an oxidizing agent to form precipitates of Mn and Co. ３＋ providing a Mn dilute leach solution containing Co ions, Cu ions, Li ions, and Ni ions in ionic form; Separating the precipitate of Mn from the Mn-dilute leachate; subjecting the Mn dilute leachate to a solvent extraction step to remove Cu ions and Ni ions from the Mn dilute leachate to form a Cu, Mn, Ni dilute leachate; subjecting the Cu-, Mn-, Ni-dilute leachate to a precipitation step to remove Co ions from the Cu-, Mn-, Ni-dilute leachate and form a Co-, Cu-, Mn-, Ni-dilute leachate; and recovering Li from the Co-, Cu-, Mn-, Ni-dilute leachate; 2. The method of claim 1, wherein prior to the step of recovering Li, the leach solution is subjected to an ammonia recovery step such that the Co-, Cu-, Ni-dilute leach solution is substantially free of ammonia during recovery of Li.

24. The leach solution further comprises ammonia, the leach solution is a first leach solution, the solid residue is a first solid residue, and after the step of separating the first leach solution from the first solid residue, the method further comprises: leaching the solid residue with a second leach solution comprising ammonium sulfate to provide a second leach solution and a second solid residue; separating the second leachate and the second solid residue; leaching the second solid residue with an acid to provide a third leachate and a third solid residue; separating the third leachate and the third solid residue; 10. The method of claim 1, further comprising combining the first infusion solution, the second infusion solution, and the third infusion solution to form a combined infusion solution.

25. 25. The method of claim 24, wherein the e-waste comprises elemental copper and one or more compounds of Co, Li, Mn, and Ni, and the method comprises recovering one or more of Co, Cu, Li, Mn, and Ni from the combined leachate.

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