RECYCLING OF ELECTRONIC WASTE TO RECOVER LITHIUM

Field

[0001] The invention generally relates to methods for recovering lithium and optionally other transition metals from waste electronic material that comprises at least copper and one or more lithium salts, and in particular, where the waste electronic material is waste lithium-ion batteries.

Background

[0002] The volume of waste electronics, and in particular, rechargeable Li-ion batteries used worldwide has been growing rapidly in recent years and is set for further expansion with the emerging markets of electric vehicles and mass electric power storage. As the demand for electronic devices, and in particular those using Li-ion batteries increases, so does the demand for the metal/metal oxide components that are used in these devices. The rapid increase in demand for some of these metals, such as cobalt, has put pressure on the sustainable supply of such resources. This has caused the cost of such metals to rapidly increase.

[0003] There has been little interest in developing processes for the recovery and recycling of the various components in modern electronic devices and components thereof such as batteries. In the case of batteries, this is mainly due to the relatively low volume of Li-ion batteries available for recycling and the relatively high cost of the typical pyrometallurgical and hydrometallurgical processes by which the recovery is achieved. As the demand for Li-ion batteries continues to increase, so too does the volume of spent Li-ion batteries that are available for recycling. There is a need for low-cost, efficient recycling processes, particularly in respect of the more complex metal/metal oxide components. Whilst the discussion below is primarily in respect of Li-ion batteries, it is applicable to a range of electronic devices since these likewise incorporate a range of different metal compounds.

[0004] The composition of Li-ion batteries has evolved considerably over recent times. Whilst some battery recycling processes have been developed, these have primarily been limited to the recovery of certain specific metals from a certain specific type of battery or feed source. For example, early batteries were predominantly lithium-cobalt and the focus of the recovery methods was on recovering cobalt. As lithium demand increased, the recovery methods shifted to the recovery of both cobalt and lithium. As battery technologies underwent further developments, the cathodes incorporated other metals, such as manganese, nickel, aluminium, iron and phosphorus. The methods used to recover lithium and cobalt are not suited for the recovery of other metals, nor are they well suited for different battery chemistries.

[0005] The uptake in the usage of Li-ion batteries will increase the volume of spent Li-ion batteries available for recycling. However, the supply of spent Li-ion batteries will include many different types of batteries. The suitability of recovery methods to only a single battery type presents a significant problem to the commercialisation of such processes. Specifically, such methods require one or more sorting steps and pre-processing steps. Given this, there is a need for the development of a process for the recovery of a range of metals from a range of different Li-ion battery types.

[0006] Most developments in battery recycling processing involve dissolution of the metal components in acidic media. This is a non-selective leaching process during which most metals contained in a battery are dissolved. Batteries contain various non-valuable metals, such as iron, manganese and aluminum, at an appreciable amount. Some batteries may also include phosphorous. Acid consumption is high if these non-valuable metals and phosphorous are not removed prior to leaching. Consequently, pretreatment processes are required to separate iron, aluminum from valuable metal components such as cobalt, nickel, copper and lithium. In so doing, the recovery of these valuable metals diminishes as the separations achieved in these pretreatment processes are not 100% efficient.

[0007] It is desirable to provide a method for the recovery of metals, and in particular lithium, from waste electronic devices such as batteries of a broad range of chemistries.

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

Summary of Invention

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

[0010] By elemental copper it is meant copper metal.

[0011] In an embodiment, the electronic waste comprises, consists of, or consists essentially of one or more types of lithium ion batteries, preferably in the form of lithium ion battery shreds. In alternative embodiments, the electronic waste comprises a mixture of one or more types of lithium ion batteries and other electronic waste, such as printed circuit boards and the like.

[0012] In an embodiment, the one or more lithium compounds comprise lithium metal oxides and/or lithium metal phosphates, such as in the form of LiMCh, LiMPCU, where M is a 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 comprises LiNiwCoxAlyMnzCh wherein w+x+y+z=l, and/or LiNixMi+Coi-x-yCh where 0 < x+y < 1 , and/or LiNivCovAL-Ch where x+y+z=l, and/or LiFcPCU.

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

[0014] In an embodiment, the elemental copper is present in an amount sufficient to provide an oxidation reduction potential of -100 mV or less as determined using an Ag/AgCl reference electrode. Preferably, the oxidation reduction potential is -150 mV or less. The inventors have found that an oxidation reduction potential of -lOOmV or less is useful for ensuring solubilisation of Li ions and reduction of transition metals in the electronic waste. In particular, the inventors have found that an oxidation reduction potential of -100 mV or less is important for forming soluble Mn ions. If the oxidation reduction potential is greater than -100 mV, Mn increasingly reports to the solid residue.

[0015] In an embodiment, the oxidant is present in an amount sufficient to provide an oxidationreduction potential of +50 mV or more as determined using an Ag/AgCl reference electrode. Preferably, the oxidation reduction potential is +100 mV or more, and more preferably +150 mV or more. [0016] In an embodiment the elemental copper is present in an amount of at least 4 wt% with respect to the total weight of the electronic 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 an embodiment, the oxidant comprises, consists of, or consists essentially of a solid oxidant. More preferably, the oxidant is in the form of a metal oxide present in the electronic waste, and in particular an oxide of Co, Mn, or Ni. In some embodiments, the oxidant is a component of the one or more lithium compounds, such as a Co, Mn, and/or Ni component of the lithium metal oxides.

[0018] The inventors have found that the leaching step mediates oxidation reduction reactions between the 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 in which Ni is present, it is preferred that the Cu:Ni ratio is 0.5:1 or greater, such as up to about 2:1.

[0020] In embodiments in which Co is present, it is preferred that the Cu:Co ratio is 0.5:1 or greater, such as up to about 2:1.

[0021] In embodiments in which Mn is present, it is preferred that the Cu:Co ratio is 0.5:1 or greater, such as up to about 2:1.

[0022] In embodiments in which 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, such as such as up to about 2:1.

[0023] In an embodiment, the temperature is from about 0 °C and up to a temperature at or less than the boiling point of the leach solution at operating conditions of the leach, for example less than 100 °C. Preferably, the temperature is from about 40 °C. Preferably the temperature is up to about 60 °C.

[0024] In an embodiment, the leach is conducted at atmospheric pressure. [0025] In an embodiment, the leach is conducted for up to 24 hours. Preferably, the leach is conducted for up to 18 hours. More preferably, the leach is conducted for up to 12 hours. Most preferably, the leach is conducted for up to 8 hours. Additionally or alternative, the leach is conducted for at least 0.5 hours. Preferably the leach is conducted for at least 1 hour. More preferably, the leach is conducted for at least 1.5 hours. Most preferably, the leach is conducted for at least 2 hours.

[0026] In an embodiment, the method further comprises recovering Cu ions from the leachate. Preferably, the Cu ions are recovered using a solvent extraction process, the solvent extraction process comprising contacting the leachate with an extractant to adsorb Cu ions into 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 form of the above embodiment, after the step of recovering Cu ions from the leachate, the method further comprises: crystallising ammonium lithium sulfate from the leachate, and thermally decomposing the crystallised ammonium lithium sulfate to form a gas comprising ammonia and sulfur oxides, and solid lithium sulfate.

[0028] Preferably, prior to the step of crystallising ammonium lithium sulfate, the leachate is treated such that the leachate is an ammonia-, Cu-, Ni-, Co-, Mn-lean leachate and/or the leachate comprises substantially no ammonia, Al, Cu, Fe, Ni, Co, or Mn.

[0029] Preferably, prior to the step of crystallising ammonium lithium sulfate, the leachate comprises ammonia-, Cu-, Ni-, Co-, Mn each at a concentration of 100 mg/L or less. Preferably, each at a concentration of 80 mg/L or less. Most preferably, each at a concentration of 60 mg/L or less.

[0030] In an embodiment, the electronic waste further comprises one or more transition metal salts, and more preferably transition metal oxides. In such cases, it is further preferred that the oxidant is the one or more transition metal salts or oxides, and the leachate comprises ions of the one or more transition metals. [0031] In one form of the above embodiment, the one or more transition metal salts are a component of the lithium metal oxides and/or lithium metal phosphates.

[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] In the case where the electronic waste further comprises one or more transition metal salts, it is further preferred that the leach is an alkaline leach, and the leach solution comprises ammonia in sufficient amount to provide a pH of from 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 an embodiment, the leach is an alkaline leach.

[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 that the pH of the leach solution is from about 8.5 up to about 10.5. Preferably, the ammonium chloride is present at a concentration of at least 1 g/L.

[0036] In an embodiment, the electronic waste further comprises one or more Ni salts, preferably in the form of oxides of Ni, and the leach solution further comprises ammonia in an amount that the pH of the leach solution is from about 8.5 to about 10.5, and wherein the leachate comprises 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 from about 1:2 to about 1:20.

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

[0039] In one form of the above embodiment, the method further comprises contemporaneously recovering Cu and Ni from the leachate via a solvent extraction process. Preferably, the solvent extraction process comprising contacting the leachate with an extractant to adsorb Cu and Ni ions into the extractant to form a Cu,Ni-loaded extractant, and separating the Cu,Ni-loaded extractant from the leachate. More preferably, the method further comprises stripping the 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 an embodiment, the electronic waste further comprises Co, and the leach solution further comprises ammonia in an amount that the pH of the leach solution is from about 8.5 to about 10.5, and wherein the leachate comprises at least Cu, Li, and Co ions.

[0041] In one form of the above embodiment, a 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 comprises recovering Cu ions from the leachate, and after removal of Cu ions, precipitating Co from the leachate.

[0043] Preferably, the step of precipitating Co from the leachate comprises precipitating cobalt sulfide from the leachate. In embodiments in which Ni and/or Mn is present in the electronic waste, the step of precipitating Co from the leachate occurs subsequent to recovery of Mn and/or Ni. That is, it is preferred that prior to the step of precipitating Co, the leachate is substantially free of Cu, Mn, and Ni. By way of example, the leachate comprises Cu and/or Mn and/or Ni each at a concentration of 100 mg/L or less. More preferably, each at a concentration of 80 mg/L or less. Most preferably, each at a concentration of 60 mg/L or less. This is to minimize the coprecipitation of sulfides of Cu, Mn, and Ni and thus provide cobalt product of higher purity.

[0044] In an embodiment, the electronic waste further comprises Mn, and the leach solution further comprises leachate comprises Mn, and the method further comprises: treating the leachate with an oxidant to form a precipitate of Mn and provide an Mn-lean leachate comprising Cu ions and Li ions; and separating the precipitate of Mn from the Mn-lean leachate.

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

[0046] In one form of the above embodiment, a ratio of Cu:Mn is from about 2:1 to about 0.5:1. [0047] In an embodiment, the electronic waste further comprises Fe and Al, the solid residue comprises Fe and Al, and the leachate is an Fe-, Al-lean leachate and/or the leachate comprises substantially no Fe or Al.

[0048] In an embodiment, the leachate comprises Fe and Al each at a concentration of 100 mg/L or less. More preferably, each at a concentration of 80 mg/L or less. Most preferably, each at a concentration of 60 mg/L or less.

[0049] In an embodiment, the electronic waste comprises elemental copper, and one or more compounds of Co, Li, and Ni, and wherein the leach solution further comprises ammonia, and 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 ions and Ni ions from the leachate and form a Cu-,Ni-lean leachate; subjecting the Cu-,Ni-lean leachate to a precipitation step to remove Co ions from the Cu-,Ni-lean leachate and form a Co-,Cu-,Ni-lean leachate; and recovering Li from the Co-,Cu-,Ni-lean leachate, wherein prior to the step of recovering Li, the leachate is subjected to an ammonia recovery step such that during the recovery of Li, the Co-,Cu-,Ni-lean leachate is substantially free of ammonia.

[0050] In one form of the above embodiment, the Co ions comprise Co ²⁺ ions, and prior to the step of subjecting the leachate to the solvent extraction step, the method further comprises treating the leachate with an oxidant to oxidise the Co ²⁺ ions to Co ³⁺ ions.

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

[0052] In an 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 leachate and a second solid residue; and 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; and combining the first leachate, the second leachate, and the third leachate to form a combined leachate.

[0053] In one form of the above embodiment, the electronic 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.

[0054] In an embodiment, the leach solution is substantially free of acid, and/or comprises no added acid species. In some instances, the natural pH of the leach solution during the leach is less than 7. In such instances, this is due to acid species that are evolved during the leach process. Thus, in preferred forms of the invention, any acids present in the leach solution are generated during the leach from the electronic waste.

[0055] In an embodiment, the leach solution is substantially free of organic compounds. By way of example, the leach solution comprises no monomers, oligomers, polymers, surfactants, organic lixiviants, organic acids, organometallic compounds and the like.

[0056] In an embodiment, the leach solution is substantially free of biological material. By way of example, the leach solution comprises no vegetable, fruit, or animal biomatter. [0057] In an embodiment, the method comprises: subjecting electronic waste to a first leach with a first leach solution to provide a first leachate and the solid residue, and leaching the leach residue with the leach solution comprising ammonium sulphate in the presence of the oxidant to provide the leachate comprising Cu ions and Li ions and the solid residue.

[0058] The skilled person will appreciate that there may be additional leaching steps between the first leach and the step of leaching the leach residue. For example, there may be a second leach with a second leach solution which results 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 and the like. However, it is preferred that the first and/or second leach solution comprises one or more of ammonia, ammonium sulfate, and ammonium chloride. In embodiments thereof, the first and/or second leach solution comprises, consists of, or consists essentially of a solution 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 leachate is combined with the first leachate (and second leachate in embodiments which include a second leaching step) to form a combined leachate from which Cu and Li can be recovered, along with Co, Mn, and Ni if present according to the methods generally described above.

[0060] Reference to any prior art in the specification is not an acknowledgment or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be understood, regarded as relevant, and/or combined with other pieces of prior art by a skilled person in the art.

[0061] As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps.

Brief Description of Drawings

[0062] Further aspects of the present 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. [0063] Figure 1 is a process flow diagram illustrating the method of the invention in accordance with one embodiment thereof.

[0064] Figure 2 is a process flow diagram illustrating the method of the invention in accordance with another embodiment thereof.

Description of Embodiments

[0065] The invention broadly relates to a method for recovering valuable metals, and in particular lithium, from electronic waste that comprises elemental copper and one or more lithium containing salts.

[0066] The method comprises leaching the electronic waste with ammonium sulfate during which the elemental copper is oxidized to copper ions thus providing a source of electrons to act as a reductant and thereby produce soluble lithium ions from the lithium containing salts. If transition metals such as cobalt, manganese, and nickel are present in the electronic waste, e.g., as a component of the lithium containing salts, or as a metal oxide and the like, these are likewise reduced to soluble ions. The various soluble metals ions, and in particular, lithium can be selectively recovered as products. The ammonium sulfate can likewise be recovered and reused for further leaching.

[0067] The method is particularly applicable to the recovery of lithium from waste lithium-ion batteries, and in particular battery shreds (whether of a single type of battery or a blend of battery shreds from different lithium-ion batteries). The method can advantageously be applied to raw battery shreds, that is, battery shreds (as opposed to black mass) that have not undergone prior treatment process such as copper stripping and/or calcination. By way of non-limiting example, the method may be applied to extract ions of Co, Cu, Li, Mn, and Ni depending on the chemistry of the battery or blend of batteries in the battery shreds.

[0068] In preferred forms of the invention, the electronic waste comprises lithium-ion batteries that include lithium metal oxides or lithium metal phosphates, a non-limiting disclosure of which includes nickel manganese cobalt (NMC), lithium cobalt oxide (LCO), and lithium-ion manganese oxide (LMO), lithium iron phosphate (LFP) and lithium nickel cobalt aluminium oxide (NCA) batteries, and mixtures thereof. Generally, in these batteries, the lithium is present in the form of one or more lithium salts of the form LiMCh, LiMPCU, where M is a transition metal, and/or LiNhCovAL-th where x + y + z = 1. The electronic waste may further comprise other electronic waste such as printed circuit boards and the like.

[0069] Without wishing to be bound by theory, the inventors are of the view that the ammonium sulfate leach mediates a copper oxidation-reduction which ultimately provides a source of electrons 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 ions of Cu, Co, Mn, and Ni depending on the chemistry of the Li-ion batteries in the battery shreds. The leach is selective in that low value metals such as iron and aluminium that may be present in the electronic waste are substantially retained in the solid residue, along with low value phosphate compounds.

[0070] In more detail, during the ammonium sulphate leach, copper metal is oxidized to Cu(I). The Cu(I) in turn is oxidised to Cu(II) via an oxidation-reduction reaction with lithium metal salts or other transition metal salts resulting in the formation of soluble ions of Li and/or of Co, Mn, and Ni (if these are present). In the absence of a source of copper metal to act as a reductant or a balance of lithium metal salts and/or other transition metal salts to act as an oxidant to convert Cu(I) to Cu(II), the oxidation-reduction reaction would cease. Generally, the method provides sufficient oxidant (in the form of lithium metal salts and/or other transition metal salts) and sufficient copper to enable the reaction to carry through to completion. If insufficient oxidant in the form of lithium metal salts and/or other transition metal salts is present, additional oxidant may be added, for example air, hydrogen peroxide, hypochlorite and the like.

[0071] The inventors have also found that introducing ammonium chloride during the leach or including it as a component of the leach solution is useful since this improves the stability of the Cu(I) ions in solution which in turn results in a more effective and efficient leach.

[0072] The resultant leachate generally comprises at least Cu and Li ions, and may additionally comprise Co, Mn, and Ni ions depending on the composition of the electronic waste. When present, the Co, Mn, and Ni ions may be selectively recovered according to methods described herein.

[0073] In the case where the leachate comprises Cu and Li ions, the Cu ions may be recovered via a solvent extraction process. That is, the leachate is contacted with an extractant to recover Cu ions from the leachate and form a Cu-loaded extractant. The extractant can then be stripped with a stripping agent, such as sulfuric acid, to recover Cu such as in the form of CuSCU (aq). [0074] The leachate, being substantially free of Cu can then be treated to recover ammonium sulphate and Li. The inventors have found that ammonium lithium sulfate can be crystallised from the leachate, e.g., by concentrating the leachate, such as by evaporating water from the leachate, to crystallise ammonium lithium sulfate. The ammonium lithium sulfate can then be recovered by a solid-liquid separation process (e.g., filtration, centrifugation, and the like) and then thermally decomposed to lithium sulfate crystals, ammonia gas, and sulfur trioxide gas. The sulfur trioxide gas can be reacted with the ammonia gas and water to regenerate ammonium sulfate.

[0075] If other transition metal ions, such as ions of Co, Mn, and Ni are present in the leachate, then these can be selectively recovered prior to the recovery of lithium. In embodiments in which Co, Mn, and Ni are present, it is preferred that Mn is recovered from the leachate prior to recovery of Cu and Ni and then recovery of Co.

[0076] In embodiments in which Mn is present, Mn ions can be recovered via oxidation of Mn to manganese oxides such as MmCh, MmCU and/or MnCh (but not MnO) a suitable oxidant is air. If Co(II) ions are present during the oxidation process, then these will be oxidised to Co(III) ions. To prevent precipitation of CoO, in addition to the oxidation of Co(II) ions to Co(III) ions, the Mn recovery step is preferably carried out in the presence of ammonia since, as discussed above, ammonia forms stable soluble sulphate complexes with Co ions, and thus mitigates against the precipitation of CoO during the oxidation treatment step. Co ions can subsequently be recovered via precipitation with a variety of different salts, for example, carbonate and/or sulfides.

[0077] In embodiments which include Ni and/or Co, the inventors have also found that introducing ammonia during the leach or including it as a component of the leach solution is useful since complexes with Ni and/or Co to form stable soluble Ni and/or Co ammonia sulphates, particularly at pH values in the range of 9-10. This aids in the selective extraction and recovery of Ni and/or Co.

[0078] In embodiments in which the leachate includes both Ni ions and Co ions, it is preferred that Cu and Ni ions are contemporaneously extracted from the leachate, followed by the recovery of Co ions, and then the recovery of Li ions. However, the skilled person will appreciate that these metal ions may be extracted or otherwise recovered from the leachate in different order and/or that other metal ions may be recovered from the leachate at intervening stages prior to the recovery of lithium or potentially after the recovery of lithium.

[0079] Ni ions can be contemporaneously extracted with Cu ions via solvent extraction. To facilitate this, the method may include an upstream oxidation step to oxidise Co ions to Co(III). This prevents cobalt from being recovered during solvent extraction, and thus poisoning of the extractant with Co(II) ions. The Ni ions can then be selectively stripped from the extractant with a stripping agent prior to stripping of Cu ions. It is preferred that the extractant is sulfuric acid, in which case Ni ions can be stripped at relatively lower sulfuric acid concentration than Cu ions thus permitting the selective recovery of Ni and Cu ions. Co can be subsequently recovered from the leachate via precipitation, e.g., with sulfide.

[0080] If ammonia is present, then this can be recovered prior to the recovery of lithium. Ammonia can be steam stripped from the leachate.

[0081] If ammonium chloride is present, this is retained in the leachate and can be recycled after the recovery of lithium from the leachate (in the form of lithium ammonium sulfate as discussed above).

[0082] The invention will be described below in relation to embodiments thereof which are intended to be illustrative in nature and should not be construed in a limiting manner.

Embodiment 1

[0083] This embodiment describes a method for the recovery of metals from a feed containing electronic waste comprising one or more lithium-ion battery types. In this embodiment, the feed comprises copper metal and metal oxides of at least cobalt, lithium, and nickel.

[0084] The method includes an initial leaching step in which lithium-ion battery waste (which may be blended with other sources of electronic waste) is subjected to an alkaline leach with a first leach solution comprising ammonium sulphate. In this embodiment, the first leach solution additionally comprises ammonia and ammonium chloride which are both found to enhance the leach process. Ammonia assists in the formation of stable soluble complexes of Ni and Co, and ammonium chloride promotes the stability of Cu(I) thus enhancing the effectiveness of the leach. The leach is carried out at atmospheric pressure and at ambient temperatures. However, the leach may be carried out at elevated temperatures, for example, at temperatures of less than the boiling point of the leach solution.

[0085] The alkaline leach oxidises elemental copper contained in the lithium-ion batteries into soluble copper ions, and this in turn provides a source of electrons to reduce or otherwise liberate cobalt, lithium, and nickel ions contained in the batteries. Thus, the leach results in the formation of a leachate comprising soluble ions of copper, cobalt, lithium, and nickel, and a solid residue. The inventors have found that a significant proportion of the contained cobalt, nickel, copper and lithium is leached into solution, for example, greater than about 90% nickel, copper and cobalt, and greater than about 70% lithium. Likewise, a significant proportion of the aluminium, iron, contained in the battery is retained in the solid residue, for example, greater than about 99% of aluminium and iron,.

[0086] The leachate can be subjected to a solvent extraction step for the extraction of copper and/or nickel. The solvent, loaded with copper and/or nickel can then be separated from the combined leachate, with copper and/or nickel subsequently being recovered from the solvent. Copper and nickel may be recovered from the solvent via stripping with a stripping agent, such as sulfuric acid. Generally, nickel can be selectively stripped with a lower residual acid concentration than for copper, e.g., in the pH range of about 1-4 with copper being subsequently stripped by increasing the acid concentration e.g., to greater than about 50 g/L H2SO4. This two- stage stripping allows the copper and nickel to be selectively recovered in separate streams.

[0087] The leachate can then be subjected to further treatment to recover cobalt. In this embodiment, cobalt is recovered via a cobalt precipitation process whereby 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 solidliquid separation process generally known to those skilled in the art, such as filtration.

[0088] The leachate, now substantially depleted of cobalt, copper, and nickel can be further treated to recover ammonia, ammonium salts, and lithium.

[0089] 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 crystallised 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 to a lithium sulfate solid, ammonia gas, and sulfur trioxide gas. The ammonia and sulfur trioxide gases can be captured and reacted together with water, such as in a wet scrubber, to form ammonium sulfate which can then be recycled to the first and/or second leaching steps.

Embodiment 2

[0090] This embodiment describes a method for the recovery of metals from a feed containing one or more lithium-ion battery types. In this particular embodiment, the feed comprises copper metal and metal oxides of at least lithium, and nickel.

[0091] The method includes an initial leaching step in which lithium-ion battery waste (which may be blended with other sources of electronic waste) is subjected to an alkaline leach with a first leach solution comprising ammonium sulphate. In this particular embodiment, the first leach solution additionally comprises ammonia which is found to enhance the leach process by promoting the formation of stable soluble Ni and Co complexes. The leach is carried out at atmospheric pressure and at ambient temperatures. However, the leach may be carried out at elevated temperatures, for example, at temperatures of less than the boiling point of the leach solution.

[0092] The alkaline leach oxidises elemental copper contained in the lithium-ion batteries into soluble copper ions, and thus provides a source of electrons to reduce or otherwise liberate nickel and lithium ions contained in the batteries. Thus, the leach results in the formation of a first leachate comprising soluble ions of copper, lithium, and nickel, and a first solid residue.

[0093] The first leachate is then separated from the first solid residue.

[0094] The first solid residue comprises low value materials such as iron and aluminium but depending on the types of lithium-ion battery waste, can also contain residual lithium and nickel compounds.

[0095] The quantities of lithium and nickel may be in amounts sufficient that warrant further treatment 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 comprising ammonium sulfate and preferably ammonium chloride. The inventors have found that ammonium chloride advantageously stabilizes Cu(I) ions. The second leach is carried out at atmospheric pressure and at ambient temperature. However, as above, the second leach may be carried out at elevated temperature, such as at temperatures of less than the boiling point of the leach solution. The second leach may be an oxidative leach. That is, an oxidant such as air, hydrogen peroxide, hypochlorite and the like may be used during the leach to aid in the recovery of metals. If the redox half-cell potential was less than 100 mV, such as is typically the case with a feed of LFP battery waste, then an oxidant is useful to aid or enhance the leaching process.

[0096] The second leach provides a second leachate comprising soluble ions of lithium and nickel, and a second solid residue.

[0097] The second leachate is then separated from the second solid residue.

[0098] The first and second leachates are then be combined to form a combined leachate which may then be subjected to a number of steps for the selective recovery of copper, lithium, and nickel.

[0099] The combined leachate can be subjected to a solvent extraction step for the extraction of copper and/or nickel. In alternative embodiments in which the leachate includes Mn ions, the leachate would first be subjected to treatment to remove Mn, e.g. through an oxidation and precipitation process as generally discussed above. In addition, in embodiments in which the leachate includes Co ions, the leachate would first be 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 with Co ions. In any case, the solvent, loaded with copper and/or nickel can then be separated from the combined leachate, with copper and/or nickel subsequently being recovered from the solvent. Copper and nickel may be recovered from the solvent via stripping with a stripping agent, such as sulfuric acid. Generally, nickel can be selectively stripped with a lower residual acid concentration than for copper, e.g., in the pH range of about 1-4 with copper being subsequently stripped by increasing the acid concentration e.g., to greater than about 50 g/L H2SO4. This two-stage stripping allows the copper and nickel to be selectively separated.

[0100] The combined leachate, now substantially depleted of copper and nickel can be further treated to recover ammonia, ammonium salts, and lithium. [0101] 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 crystallised 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 to a lithium sulfate solid, ammonia gas, and sulfur trioxide gas. The ammonia and sulfur trioxide gases can be captured and reacted together with water, such as in a wet scrubber, to form ammonium sulfate which can then be recycled to the first and/or second leaching steps.

[0102] Figure 1 is a process flow diagram illustrating a method in accordance with the abovedescribed embodiment. The method of Figure 1 describes the recovery of a copper product 18 and a lithium product 30. In this embodiment, a feed stream 1 is subjected to a pre-treatment process, for example shredding 100, to render the feed stream 1 suitable for further processing, which is typically <5mm. The resulting shredded feed stream 2 is then passed to an alkaline leach circuit 110, in which it is contacted with a liquor containing ammonia, ammonium sulfate with/without ammonium chloride 19, and ammonia top-up 3 and 22 to solubilise copper. The alkaline leach circuit is operated, for example, at about 50 °C, atmospheric pressure, about pH 9.0, at about 10% solids. The resultant alkaline leached slurry 4 is subjected to a solid liquid separation step 120, such as a thickener, or number of thickeners with washing, and the ammonia leach liquor 6, is directed to the solvent extraction circuit 160.

[0103] Thickener underflow 5 is directed to an ammonium sulfate leach circuit 130, where it is contacted with a solution containing ammonium sulfate 24 and 32 and ammonium sulfate top-up 7. Air 8 is sparged to the leach circuit 130. The ammonium sulfate leach is operated at about 100 °C, about Eh 120 mV (Ag/AgCl electrode) and at about 10% solids. The ammonium sulfate leach discharge 9 is directed to a thickener 140. Thickener underflow 11 is directed to a filter 150, whereby the thickened slurry is filtered. The resulting filter cake is washed with water 12 and the filtrate and wash filtrate are combined with the thickener overflow 10 and ammonia leach liquor 6.

[0104] The pregnant leach liquor is directed to a copper solvent extraction circuit 160 where it is contacted with a copper extractant, such as a commercially available oxime extractant, for example LIX84I™. Copper is loaded onto the copper extractant and a loaded extractant 14 is separated from a raffinate 19. The loaded extractant 14 is contacted with dilute sulfuric acid 16 or anolyte from a copper electrowinning stage 180 in a copper strip stage 170 to produce a loaded strip liquor 15 containing copper and a copper depleted extractant. A stripped organic (not shown) is recycled (not shown) to the extraction circuit 160 to extract more copper. A copper product 18 is recovered from the copper loaded strip liquor 15 in a copper electrowinning stage 180.

[0105] The copper depleted raffinate 19, which contains ammonia and ammonium sulfate, is directed to the ammonia leach circuit 110 to recover more metal. The remaining filtrate 29 is directed to an ammonia recovery circuit 190, in which steam 21 is used to strip ammonia 22. Recovered ammonia 22 is re-used in the process, specifically for example in the ammonia leach 110.

[0106] Ammonia free liquor 24 is directed to the ammonium sulfate leach 130 and also to a crystalliser 200 in which condensate 25 is removed by forced evaporation and lithium ammonium sulfate 26 is crystallised. The crystalliser discharge is subjected to solid liquid separation using a centrifuge 210 and the centrate 27 is directed to the ammonium sulfate leach 130. The lithium ammonium sulfate 28 is subjected to calcination in a kiln 220 in which the solids, lithium sulfate 30, are collected for sale and an off-gas 29 is collected in a wet scrubber, utilising scrub water 31, to recover ammonium sulfate solution 32. This liquor is directed to the ammonium sulfate leach 130.

Embodiment 3

[0107] This embodiment describes a method for the recovery of metals from a feed containing one or more lithium-ion battery types. In this particular embodiment, the feed comprises copper metal and metal oxides of at least cobalt, lithium, manganese, and nickel.

[0108] The method includes an initial leaching step in which lithium-ion battery waste (which may be blended with other sources of electronic waste) is subjected to an alkaline leach with a first leach solution comprising ammonium sulphate. In this particular embodiment, the first leach solution additionally comprises ammonia which is found to enhance the leach process as described previously. The leach is carried out at atmospheric pressure and at ambient temperatures. However, the leach may be carried out at elevated temperatures, for example, at temperatures of less than the boiling point of the leach solution. [0109] The alkaline leach oxidises elemental copper contained in the lithium-ion batteries into 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-ion manganese oxide (LMO) batteries. Thus, the leach results in the formation of a first leachate comprising soluble ions of cobalt, copper, lithium, manganese, and nickel, and a first solid residue.

[0110] The first leachate is then separated from the first solid residue.

[0111] The first solid residue comprises low value materials such as iron and aluminium but depending on the types of lithium-ion battery waste, can also contain residual cobalt, lithium, manganese and nickel compounds. For example, where the feed comprises lithium iron phosphate (LFP) and lithium nickel cobalt aluminium oxide (NCA) batteries, some of the cobalt, lithium, and nickel is retained in the first solid residue.

[0112] The quantities of cobalt, lithium, manganese, and nickel may be in amounts sufficient that further recovery of these metals is economically viable and thus desirable. If so, the first solid residue may be subjected to a further leaching step with a second leach solution comprising ammonium sulfate and preferably ammonium chloride. The second leach is carried out at atmospheric pressure and at ambient temperature. However, as above, the second leach may be carried out at elevated temperature, such as at temperatures of less than the boiling point of the leach solution. The second leach may be an oxidative leach. That is, an oxidant such as air, hydrogen peroxide, hypochlorite and the like may be used during the leach to aid in the recovery of metals. Generally, with a feed that comprises NCA and/or NMC battery materials an oxidant is not required since cobalt, nickel, and manganese are present in sufficient quantities to provide a sufficiently high redox half-cell potential of >100 mV. However, if the redox half-cell potential was less than 100 mV, such as is typically the case with a feed of LFP battery waste, then an oxidant is useful to aid or enhance the leaching process.

[0113] The second leach provides a second leachate comprising soluble ions of cobalt, lithium, manganese, and nickel, and a second solid residue.

[0114] The second leachate is then separated from the second solid residue. As above, depending on the types of batteries present, the second solid residue may contain residual cobalt, lithium, manganese, and nickel in commercially recoverable amounts. [0115] 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% of the residual nickel and also contains some residual cobalt, lithium, and manganese. The fine fraction is subjected to an acid leach, such as with sulfuric acid, to provide a third leachate comprising ions of cobalt, lithium, manganese, and nickel, and a third solid residue. The third leach is carried out at atmospheric pressure and at ambient temperature. However, as above, the third leach may be carried out at elevated temperature, such as at temperatures of less than the boiling point of the leach solution.

[0116] The third leachate is then separated from the third solid residue.

[0117] It will be appreciated that in alternative embodiments, the third acid leach step is omitted.

[0118] Aluminium, iron, and phosphate are not extracted to significant amounts and are generally retained in the first, second, and/or third solid residues. Given this, the leaching process is selective for higher value metals such as copper, cobalt, lithium, manganese, and nickel.

[0119] The first, second, and third leachates may then be combined to form a combined leachate which may then be subjected to a number of steps for the selective recovery of cobalt, copper, lithium, manganese, and nickel.

[0120] To recover 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 MmCh, MmC and/or MnCh (but not MnO). The inventors have found that where the leachate additionally comprises cobalt ions, the presence of ammonia is important to complex with the cobalt ions to retain these in the form of soluble Co(III) ions and prevent the formation of a CoO precipitate. The manganese oxide precipitate can then be recovered from the combined leachate using any solid-liquid separation process generally known to those skilled in the art, such as filtration.

[0121] The combined leachate can then be subjected to a solvent extraction step for the extraction of copper and/or nickel. The solvent, loaded with copper and/or nickel can then be separated from the combined leachate, with copper and/or nickel subsequently being recovered from the solvent. Copper and nickel may be recovered from the solvent via stripping with a stripping agent, such as sulfuric acid. Generally, nickel can be selectively stripped with a lower residual acid concentration than for copper, e.g., in the pH range of about 1-4 with copper being subsequently stripped by increasing the acid concentration e.g., to greater than about 50 g/L H2SO4. This two-stage stripping allows the copper and nickel to be selectively separated.

[0122] In alternative embodiments, Cu and Ni can be recovered prior to Mn recovery.

[0123] The combined leachate can then be subjected to further treatment to recover cobalt. In this embodiment, cobalt is recovered via a cobalt precipitation process whereby the combined leachate is treated with a sulfide, such as hydrogen sulfide gas or ammonium sulfide, to precipitate cobalt sulfide. The cobalt sulfide can then be recovered from the combined leachate using any solid-liquid separation process generally known to those skilled in the art, such as filtration.

[0124] The combined leachate, now substantially depleted of cobalt, copper, manganese, and nickel can be further treated to recover ammonia, ammonium salts, and lithium.

[0125] 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 crystallised 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 to a lithium sulfate solid, ammonia gas, and sulfur trioxide gas. The ammonia and sulfur trioxide gases can be captured and reacted together with water, such as in a wet scrubber, to form ammonium sulfate which can then be recycled to the first and/or second leaching steps.

[0126] The process is described in more detail with reference to Figure 2. Figure 2 is a process flow diagram illustrating the method of the invention according to the embodiment generally described above.

[0127] The method of Figure 2 describes the recovery of a nickel product 27, a copper product 32, a cobalt product 37 and a lithium product 48. In this embodiment, feed stream 1 is subjected to a pre-treatment process, for example shredding 100 to <5mm, for example <lmm, to render the feed stream 1 suitable for further processing. The resulting shredded feed stream 2 is then passed to an alkaline leach circuit 110, in which it is contacted with a liquor containing ammonia, ammonium sulfate with/without ammonium chloride 39, and ammonia top-up 3 and 40 to solubilise metal species. Conditions in the alkaline leach circuit 110 include about 5-10% solids, about 50°C, atmospheric pressure, about a 12 hour residence time, a pH of about 9 with ammonia about 200 g/L ammonium sulfate, and about 20 g/L ammonium chloride if present.

[0128] The resultant alkaline leached slurry 4 is subjected to a solid liquid separation step 120, such as a thickener, or number of thickeners with washing, and the ammonia leach liquor 6, is directed to the manganese oxide precipitation circuit 180.

[0129] The thickener underflow 5 is directed to an ammonium sulfate leach circuit 130, where it is contacted with a solution containing ammonium sulfate 47 and ammonium sulfate top-up 7. Conditions in the ammonium sulfate leach circuit 130 include about 5-10% solids, about 100 - 105°C, atmospheric pressure, about 4 - 12 hours residence time, about 200 g/L ammonium sulfate and 20 g/L ammonium chloride.

[0130] The ammonium sulfate leach discharge 8 is directed to a screen 140, for example of between 75 - 500 pm, for example about 180 pm, to separate a coarse fraction and a fine fraction of particles. The coarse fraction 9 is stored and the fine fraction 10 is directed to a thickener 150. The thickener overflow, for example ammonium sulfate leach liquor 11, is directed to a manganese oxide precipitation circuit 180.

[0131] The thickener underflow 12 is directed to an acid leach circuit 160, where it is contacted with sulfuric acid 13. The conditions for the acid leach circuit 160 included a temperature in the range of about 20 to 100°C, for example 70°C, a pH of less than about 3, for example a pH of about 1.5, a residence time of between about 4 - 12 hours, 30% solids and 98% acid addition.

[0132] An acid leach discharge 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, that is directed to the manganese oxide precipitation circuit 180.

[0133] The leach liquors 6, 11 and 17 are directed to the manganese oxide precipitation circuit 180 in which air 18 is sparged into the liquor to force the precipitation of manganese oxides. A precipitation slurry 19 is subject to solid liquid separation by thickening and filtration 190. A manganese product 20 is washed and stored.

[0134] A pregnant leach liquor post manganese precipitation 21 is directed 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, for example LIX84I™. Copper and nickel are loaded onto the copper extractant and a loaded extractant 23 is separated from a raffinate 22. The loaded extractant 23 is contacted with dilute sulfuric acid 24, for example 150 g/L sulfuric acid, in a nickel strip stage 210 to produce a loaded strip liquor containing nickel 25 and a nickel depleted extractant 28. The nickel depleted extractant 28 is contacted with dilute sulfuric acid liquor 29, for example 200 g/L sulfuric acid, in the copper strip stage 220 to produce a loaded strip liquor 30 containing copper. A stripped organic (not shown) is recycled (not shown) to the extraction circuit 200 to extract more copper and nickel. A nickel product 27 (ostensibly in the form of nickel sulfate) is recovered from the nickel loaded strip liquor 25 in a nickel crystallisation stage 230. A copper product 32 (ostensibly in the form of copper sulfate) is recovered from the copper loaded strip liquor 30 in a copper electrowinning stage 240.

[0135] The copper and nickel depleted raffinate 22 is directed to a cobalt recovery circuit 250 in which a precipitation reagent, for example hydrogen sulfide gas 33, is added to force the precipitation of cobalt sulfide. A resulting slurry 34 is subjected to solid liquid separation, for example by way of a thickener and filter 260, and washed with water 35 to produce a cobalt product 37.

[0136] Most of a resulting filtrate 39, which contains ammonia and ammonium sulfate, is directed to the ammonia leach circuit 110 to recover more metal. The remaining filtrate 38 is directed to an ammonia recovery circuit 270, in which steam 41 is used to strip ammonia 40. A recovered ammonia 40 is re-used in the process, specifically for example in the ammonia leach 110.

[0137] An ammonia free liquor 42 is directed to the ammonium sulfate leach 130 and also to a crystalliser 280 in which a condensate 43 is removed by forced evaporation and lithium ammonium sulfate 46 is crystallised. The crystalliser discharge is subjected to solid liquid separation using a centrifuge 290 and the centrate 45 is directed to the ammonium sulfate leach 130. The lithium ammonium sulfate 46 intermediate is subjected to calcination in a kiln 300 in which the solids, lithium sulfate 48, are collected for sale and an off-gas 47 is collected in a wet scrubber, utilising scrub water 49, to recover ammonium sulfate solution 50.

Examples

Example 1

[0138] This example reports a single stage alkaline leach of raw lithium-ion nickel manganese cobalt 622 (NMC622) battery shreds with a leach solution of ammonium sulfate, ammonia, and ammonium chloride.

[0139] The NMC battery shreds contained 22.9 wt% Cu, 12.5 wt% Ni, 4.9 wt% Co, 6.2 wt% Mn and 2.94 wt% Li on an elemental basis. Elemental copper was present in sufficient amount to provide an oxidation reduction potential of less than -150 mV (Ag/AgCl electrode) during the leach.

[0140] The NMC battery shreds were reacted with an aqueous leach solution containing 169 g/L ammonium sulfate, 46g/L ammonia and 14.5 g/L ammonium chloride at a loading of 3.8 wt% solids. The leach was carried out at a pH of 9.5, at atmospheric pressure, and a temperature of 50 °C for 2 hours.

[0141] 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.

[0142] Although not reported in this example, nickel, cobalt, copper, lithium and manganese can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonium sulfate, ammonia, and ammonium chloride can be recovered for reuse using the methods disclosed herein.

Example 2

[0143] This example reports a three- stage leach of a blended 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 shreds with a leach solution of ammonium sulfate, ammonia, and ammonium chloride. [0144] An equal weight blend of NMC811, NMC622, NCA and LFP battery shreds 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 sufficient amount to provide an oxidation reduction potential of less than -150 mV (Ag/AgCl electrode) during the leach.

[0145] The battery shred blend was first subjected to an alkaline leach in a solution containing 215g/L ammonium sulfate, 105g/L ammonia and 21g/L ammonium chloride at loading of 9.8 wt% solids. The leach was carried out at a pH range of 9.4-9.9, at atmospheric pressure, and at a temperature of 50 °C for 6 hours.

[0146] 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.

[0147] 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.

[0148] This solid residue was separated from the leachate and subjected to a second leach with a solution containing 343g/L ammonium sulfate and 34g/L ammonium chloride at a loading of 6.9 wt% solids. The leach was carried out in a solution such that the natural pH was in the range of 5.1-5.3 and the natural oxidation reduction potential was 165mV (Ag/AgCl electrode). The leach was conducted at atmospheric pressure and at a temperature of 100 °C for a period of 6 hours.

[0149] The extraction of nickel, cobalt, copper, lithium and manganese reached 59.4%, 82.2%, 33.8%, 94.3% and 94.7%, respectively. The metals, with the exception of nickel, were extracted from all battery types. Nickel was extracted mainly from NMC811 and NMC622 material that was not leached in the preceding alkaline leach.

[0150] The extraction of nickel, cobalt, copper, lithium and manganese in the leachate across both leach stages reached 74.7%, 92.5%, 87.7%, 97.0% and 98.3%, respectively.

[0151] The solid residue from the second leach was initially screened at 180 micron to remove coarse material, in particular steel and aluminium 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. [0152] The solid residue was re-pulped in water to 30% solids then sulfuric acid was added to a target pH 1.50. After 6 hours of leaching at 70 °C the extraction of nickel, cobalt, copper, lithium and manganese reached 99.5%, 99.0%, 98.8%, 96.3% and 92.6%, respectively. The acid consumption was significantly lower (<200kg/t) than an equivalent sulfuric acid only flowsheet (>1200kg/t).

[0153] The extraction of nickel, cobalt, copper, lithium and manganese into the leachate across all three leach stages and including metal losses associated with screening, reached 96.8%, 98.2%, 97.7%, 98.6% and 93.0%, respectively.

[0154] The leachates from the three leach steps can be combined and subsequently treated for the selective recovery of nickel, cobalt, copper, lithium and manganese using methods disclosed herein. Likewise, the ammonium sulfate, ammonia, and ammonium chloride can be recovered for reuse using the methods disclosed herein.

Example 3

[0155] This example reports the oxidative leach of raw lithium iron phosphate (LFP) battery shreds with a single stage aqueous leach solution of ammonium sulfate and ammonium chloride.

[0156] The LFP battery shreds contained 6.7 wt% Cu and 1.99 wt% Li on an elemental basis.

[0157] The LFP battery shreds 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 oxidation reduction potential of +150 mV (Ag/AgCl electrode).

[0158] The leach was carried out at the natural pH which was in the range of 4.9-5.2, at atmospheric pressure, and a temperature of 100 °C for 4 hours.

[0159] The extraction of copper and lithium into the leachate was found to be 83.4% and 92.5% respectively. Only 0.5% Fe was co-extracted.

[0160] Although not reported in this example, copper and lithium can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein. Example 4

[0161] This example reports the leach of raw lithium-ion nickel manganese cobalt 811 (NMC811) battery shreds with a single stage aqueous leach solution of ammonium sulfate and ammonium chloride.

[0162] The NMC811 battery shreds contained 2.46 wt% Cu, 22.2 wt% Ni, 2.72 wt% Co, 1.72 wt% Mn and 2.83 wt% Li on an elemental basis.

[0163] The NMC811 battery shreds 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 at an amount of 250 kg/t, which may be introduced in the form of scrap electronics e.g., printed circuit boards and the like.

[0164] The leach was carried out at the natural pH which was in the range of 4.7-5.5, a natural redox potential of about 15-150 mV (Ag/AgCl electrode), at atmospheric pressure, and a temperature of 100 °C for 4 hours.

[0165] 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.

[0166] Although not reported in this example, copper, nickel, cobalt, manganese and lithium can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

Example 5

[0167] This example reports the leach of raw lithium nickel cobalt aluminum Oxide (NCA) battery shreds with a single stage aqueous leach solution of ammonium sulfate and ammonium chloride.

[0168] The NCA battery shreds contained 0.95 wt% Cu, 24.3 wt% Ni, 2.77 wt% Co, 0.02 wt% Mn and 3.20 wt% Lion an elemental basis. [0169] The NCA battery shreds 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 at an amount of 250 kg/t, which may be introduced in the form of scrap electronics e.g., printed circuit boards and the like.

[0170] The leach was carried out at the natural pH which was in the range of 4.5-4.9, a natural redox potential of about -16-30 mV (Ag/AgCl electrode), at atmospheric pressure, and a temperature of 100 °C for 4 hours.

[0171] The extraction of copper, nickel, cobalt, manganese and lithium into the leachate was 87%, 33.4%, 58.9%, 58.2% and 94.6%, respectively.

[0172] Although not reported in this example, copper, nickel, cobalt, manganese and lithium can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

Example 6

[0173] This example reports the alkaline leach of raw lithium-ion manganese oxide (LMO) battery shreds with a single stage aqueous leach solution of ammonia, ammonium sulfate, and ammonium chloride.

[0174] The LMO battery shreds contained 3.28 wt% Cu, 3.65 wt% Ni, 1.24 wt% Co, 27.9 wt% Mn and 2.52 wt% Li on an elemental basis.

[0175] The LMO battery shreds were reacted with an aqueous leach solution containing 45g/L ammonia, 180g/L ammonium sulfate and 18g/L ammonium chloride at a loading of 4.0 wt% solids. Additional copper metal was added at an amount of 250 kg/t, which may be introduced in the form of scrap electronics e.g., printed circuit boards and the like.

[0176] The leach was carried out at the natural pH which was in the range of 8.8 -9.1, a redox potential of about -123 to -250 mV (Ag/AgCl electrode), at atmospheric pressure, and a temperature of 50 °C for 4 hours. [0177] 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.

[0178] Although not reported in this example, copper, nickel, cobalt, manganese and lithium can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonia, ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

Example 7

[0179] This example reports the alkaline leach of raw lithium cobalt oxide (LCO) battery shreds with a single stage aqueous leach solution of ammonia, ammonium sulfate, and ammonium chloride.

[0180] The LCO battery shreds contained 5.42 wt% Cu, 28.6 wt% Co and 3.46 wt% Li on an elemental basis.

[0181] The LCO battery shreds were reacted with an aqueous leach solution containing 45g/L ammonia, 180g/L ammonium sulfate and 18g/L ammonium chloride at a loading of 4.0 wt% solids.

[0182] The leach was carried out at the natural pH of 9.2, a redox potential of -150 mV (Ag/AgCl electrode), at atmospheric pressure, and a temperature of 50 °C for 2 hours. After 2 hours, the extraction of copper, cobalt and lithium into the leachate was 93.8%, 24.1% and 25.9%, respectively.

[0183] lOOkg/t of copper was then added and the leaching was carried out for an additional 2 hours. After the additional 2 hours of leaching, the extraction of copper, cobalt and lithium into the leachate reached 97.6%, 67.5% and 68.9%, respectively.

[0184] This example demonstrates that higher metal extraction occurs with the addition of copper.

[0185] Although not reported in this example, copper, cobalt, and lithium can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonia, ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

Example 8

[0186] This example reports a three-stage leach of a blended 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 shreds with a leach solution of ammonium sulfate and ammonia. No ammonium chloride was added.

[0187] An equal weight blend of NMC811, NMC622, NCA and LFP battery shreds, containing 7.01% Cu, 14.5% Ni, 2.48% Co, 2.16% Mn and 2.69% Li was reacted in a solution containing 220g/L ammonium sulfate and HOg/L ammonia at 9.1% solids and 50C. After 6 hours of leaching at pH 9.5-9.9 and an oxidation reduction potential of less than -90 mV (Ag/AgCl electrode), the extraction of nickel, cobalt, copper, lithium and manganese reached 58.8%, 45.8%, 49.4%, 47.4% and 78.3%, respectively. The metals were extracted mainly from NMC622 and NMC811 batteries.

[0188] 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.

[0189] This solid residue was reacted in a solution containing 354g/L ammonium sulfate at 5.1% solids and 100C. After 6 hours of leaching, in which the natural pH was 4.2-5.4 and the natural oxidation reduction potential was 360-530mV (Ag/AgCl electrode), the extraction of nickel, cobalt, copper, lithium and manganese reached 15.1%, 77.6%, 67.7%, 75.5% and 8.5%, respectively. The metals, with the exception of nickel, were extracted from all battery types. Nickel was extracted mainly from NMC811 and NMC622 material that was not leached in the primary leach.

[0190] The extraction of nickel, cobalt, copper, lithium and manganese across both leach stages reached 64.5%, 85.5%, 87.5%, 86.1% and 79.8%, respectively.

[0191] The solid residue from the second leach was initially screened at 180 micron to remove coarse material, in particular steel and aluminium foil. The screen undersize contained 1.61% Cu, 8.2% Ni, 0.49% Co, 0.69% Mn and 0.59% Li. [0192] The solid residue was re-pulped in water to 30% solids then sulfuric acid was added to a target pH 1.90. After 6 hours of leaching at 70 °C the extraction of nickel, cobalt, copper, lithium and manganese reached 58.9%, 98.3%, 37.1%, 64.9% and 7.0%, respectively. The acid consumption was significantly lower (<100kg/t) than an equivalent sulfuric acid only flowsheet (>1200kg/t). Higher metal extraction is expected with higher acid addition.

[0193] The extraction of nickel, cobalt, copper, lithium and manganese across all three leach stages and including metal losses associated with screening, reached 85.7%, 92.3%, 99.7%, 95.5% and 80.0%, respectively.

Example 9

[0194] This example reports the leach of a mixture of lithium iron phosphate (LFP) and nickel cobalt aluminum (NCA) battery shreds at an LFP:NCA mass ratio of 4:1 with a single stage aqueous leach solution of ammonium sulfate and ammonium chloride.

[0195] The battery shreds contained 0.26 wt% Cu, 4.39 wt% Ni, 0.50 wt% Co, 19.0 wt% Fe and 1.99 wt% Ei on an elemental basis.

[0196] The battery shreds were reacted with an aqueous leach solution containing 230g/E ammonium sulfate, 23g/E ammonium chloride and 5.5 g/E Cu (as copper sulfate) at a loading of 4.9 wt% solids. Copper sulfate was added due to the low copper grade of the battery shreds.

[0197] The leach was carried out at natural pH which was in the range of 4.80-5.13, a redox potential of +123 to +180 mV (Ag/AgCl electrode), at atmospheric pressure, and a temperature of 100 °C for 8 hours.

[0198] The extraction of nickel, cobalt, iron and lithium into the leachate was 44.0%, 75.7%, 0.43% and 94.7%, respectively.

[0199] Although not reported in this example, copper, nickel, cobalt and lithium can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein. Example 10

[0200] This example reports the leach of a mixture of lithium iron phosphate (LFP) and nickel cobalt aluminum (NCA) battery shreds at an LFP:NCA mass ratio of 4:1 with a single stage aqueous leach solution of ammonium sulfate. No ammonium chloride was added to the leach.

[0201] The battery shreds contained 0.26 wt% Cu, 4.39 wt% Ni, 0.50 wt% Co, 19.0 wt% Fe and 1.99 wt% Ei on an elemental basis.

[0202] The battery shreds were reacted with an aqueous leach solution containing 230g/E ammonium sulfate and 5.5 g/E Cu (as copper sulfate) at a loading of 4.9 wt% solids. Copper sulfate was added due to the low copper grade of the battery shreds.

[0203] The leach was carried out at natural pH which was in the range of 4.22-5.05, a redox potential of +91 to +126 mV (Ag/AgCl electrode), at atmospheric pressure, and a temperature of 100°C for 8 hours.

[0204] The extraction of nickel, cobalt, iron and lithium into the leachate was 20.5%, 43.4%, 0.26% and 81.6%, respectively.

[0205] Although not reported in this example, copper, nickel, cobalt, manganese and lithium can be selectively recovered from the leachate using methods disclosed herein. Likewise, the ammonium sulfate and ammonium chloride can be recovered for reuse using the methods disclosed herein.

[0206] It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.