TW202425395A - Recycling of electronic waste to recover lithium - Google Patents

Abstract

Disclosed herein is 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.

Description

Recycling Electronic Waste for Lithium

The present invention generally relates to a method for recovering lithium and any other transition metals from waste electronic materials comprising at least copper and one or more lithium salts, in particular, wherein the waste electronic materials are waste lithium-ion batteries.

The amount of obsolete electronic products used worldwide, especially rechargeable lithium-ion batteries, has been growing rapidly in recent years, and will continue to grow with the development of emerging markets such as electric vehicles and large-capacity power storage. As demand for electronic devices, especially those using lithium-ion batteries, increases, demand for metal/metal oxide components used in these devices is also increasing. The rapid growth in demand for some of these metals, such as cobalt, has put pressure on the sustainable supply of these resources. This has led to a rapid increase in the cost of these metals.

There has been little interest in developing processes to recover and recycle the various components and parts of modern electronic devices, such as batteries. In the case of batteries, this is primarily due to the relatively small number of lithium-ion batteries available for recycling and the relatively high cost of traditional pyrometallurgical and hydrometallurgical processes to achieve recycling. As the demand for lithium-ion batteries continues to increase, the amount of spent lithium-ion batteries available for recycling is also increasing. There is a need for low-cost, efficient recycling processes, particularly for the more complex metal/metal oxide compositions. Although the following discussion focuses on lithium-ion batteries, it is applicable to a range of electronic devices as they also contain a range of different metal compounds.

The composition of lithium-ion batteries has changed significantly in recent years. Although some battery recycling processes have been developed, these processes are mainly limited to recovering certain specific metals from certain types of batteries or raw materials. For example, the vast majority of early batteries were lithium-cobalt batteries, and the focus of recycling methods was on recovering the cobalt. As the demand for lithium increased, recycling methods shifted to recovering both cobalt and lithium. As battery technology developed further, other metals were added to the cathode, such as manganese, nickel, aluminum, iron and phosphorus. Methods for recovering lithium and cobalt are not applicable to recovering other metals, nor are they applicable to different battery chemistries.

As the use of lithium-ion batteries increases, the amount of spent lithium-ion batteries available for recycling will also increase. However, the supply of spent lithium-ion batteries will contain many different types of batteries. Recycling methods that are only applicable to a single battery type pose significant problems for the commercialization of such processes. Specifically, such methods require one or more sorting steps and pre-treatment steps. In view of this, it is necessary to develop a process that can recover a variety of metals from a variety of different types of lithium-ion batteries.

Most battery recycling processes are developed with regard to the dissolution of metal components in an acidic medium. This is a non-selective leaching process, during which most of the metals contained in the battery are dissolved. Batteries contain large amounts of various cheap metals such as iron, manganese and aluminum. Some batteries may also contain phosphorus. If these cheap metals and phosphorus are not removed before leaching, the acid consumption is high. Therefore, pre-treatment processes are required to separate iron and aluminum from valuable metal components such as cobalt, nickel, copper and lithium. This is done because the separation in these pre-treatment processes is not 100% effective and the recovery rate of these valuable metals is reduced.

It would be desirable to provide a method for recovering metals, particularly lithium, from discarded electronic devices such as batteries having a wide range of chemistries.

The object of the present invention is to solve one or more disadvantages of the prior art and/or to provide a useful alternative.

In one embodiment of the present invention, a method for recovering metals from electronic waste or leaching residue thereof is provided, wherein the electronic waste or leaching residue contains copper element and one or more lithium compounds, and the method comprises: Leaching the electronic waste or the leaching residue with a leaching solution containing ammonium sulfate in the presence of an oxidant to provide a leaching solution containing copper ions and lithium ions and a solid residue; and Separating the leaching solution and the solid residue.

The copper element refers to the copper metal.

In one embodiment, the electronic waste is composed of one or more types of lithium-ion batteries, preferably in the form of lithium-ion battery fragments. In an alternative embodiment, the electronic waste comprises a mixture of one or more types of lithium-ion batteries and other electronic waste such as printed circuit boards.

In one embodiment, the one or more lithium compounds include lithium metal oxides and/or lithium metal phosphates, such as in the form of LiMO ₂ , LiMPO ₄ , wherein M is one or more metals selected from the group consisting of aluminum, cobalt, manganese and/or nickel. In a preferred form, the one or more lithium metal compounds include LiNi w Co x A ly M nz O 2 , wherein w+x+y+z=1, and/or LiNixMnyCo _1-xy O ₂ , wherein 0 ≤ x+y ≤ 1, and/or LiNi _x Co _y Al _z O ₂ , wherein x+y+z=1, and/or LiFePO ₄ .

In one embodiment, the copper ions and _lithium ions exist in the form of CuSO4 and _Li2SO4 , respectively.

In one embodiment, the copper element is present in an amount sufficient to provide a redox potential of -100 mV or less, measured using an Ag/AgCl reference electrode; ideally, 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 dissolution of lithium ions in the electronic waste and the reduction of transition metals. In particular, the inventors have found that a redox potential of -100 mV or less is important for the formation of soluble manganese ions. If the redox potential is greater than -100 mV, manganese will appear more and more in the solid slag.

In one embodiment, the oxidant is present in an amount sufficient to provide a redox potential of +50 mV or more, as measured using an Ag/AgCl reference electrode. Ideally, the redox potential is +100 mV or more, and more ideally, the redox potential is +150 mV or more.

In one embodiment, the copper element is present in an amount of at least 4 wt% relative to the total weight of the electronic waste. Ideally, the copper element is present in an amount of at least 5 wt% relative to the total weight of the electronic waste. More ideally, the copper element is present in an amount of at least 6 wt% relative to the total weight of the electronic waste. Even more ideally, the copper element is present in an amount of at least 7 wt% relative to the total weight of the electronic waste. Most ideally, the copper element is present in an amount of at least 8 wt% relative to the total weight of the electronic waste.

In one embodiment, the oxidant comprises, consists of or consists essentially of a solid oxidant. More preferably, the oxidant is present in the electronic waste in the form of a metal oxide, particularly an oxide of cobalt, manganese or nickel. In some embodiments, the oxidant is a component of one or more lithium compounds, such as a cobalt, manganese and/or nickel component of a lithium metal oxide.

The inventors have discovered that the aforementioned leaching step promotes redox reactions between the copper element and the cobalt, manganese and nickel salts, which is beneficial to the formation of soluble salts of cobalt, copper, manganese and nickel ions.

In embodiments where nickel is present, the ideal copper:nickel ratio is 0.5:1 or greater, such as up to about 2:1.

In embodiments where cobalt is present, the copper:cobalt ratio is ideally 0.5:1 or greater, such as up to about 2:1.

In embodiments where manganese is present, the copper:cobalt ratio is ideally 0.5:1 or greater, such as up to about 2:1.

In embodiments where nickel and/or cobalt and/or manganese are present, the ideal copper:(nickel+cobalt+manganese) ratio is 0.5:1 or greater, such as up to about 2:1.

In one embodiment, the temperature is from about 0°C to up to the boiling point of the leachate under the leaching operating conditions or below, such as 100°C or below. Ideally, the temperature is from about 40°C. Ideally, the temperature is up to about 60°C.

In one embodiment, the leaching is performed under atmospheric pressure.

In one embodiment, the leaching is performed for up to 24 hours. Ideally, the leaching is performed for up to 18 hours. More ideally, the leaching is performed for up to 12 hours. Most ideally, the leaching is performed for up to 8 hours. Additionally or alternatively, the leaching is performed for at least 0.5 hours. Ideally, the leaching is performed for at least 1 hour. More ideally, the leaching is performed for at least 1.5 hours. Most ideally, the leaching is performed for at least 2 hours.

In one embodiment, the method further comprises recovering copper ions from the leachate. Ideally, the copper ions are recovered using a solvent extraction method, which comprises contacting the leachate with an extractant so that the copper ions are adsorbed into the extractant to form a copper-loaded extractant, and separating the copper-loaded extractant from the leachate. More ideally, the method further comprises extracting the copper ions from the copper-loaded extractant using an extractant such as sulfuric acid.

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

Ideally, before the step of crystallizing the ammonium lithium sulfate, the leachate is treated to make the leachate poor in ammonia, copper, nickel, cobalt, or manganese, and/or to make the leachate substantially free of ammonia, aluminum, copper, iron, nickel, cobalt, or manganese.

Ideally, prior to the step of crystallizing lithium ammonium sulfate, the leaching solution contains ammonia, copper, nickel, cobalt, and manganese, each at a concentration of 100 mg/L or less. Ideally, each at a concentration of 80 mg/L or less. Most ideally, each at a concentration of 60 mg/L or less.

In one embodiment, the electronic waste further comprises one or more transition metal salts, more preferably, transition metal oxides. In this case, it is further desirable that the oxidant is one or more transition metal salts or oxides, and the leaching solution comprises one or more transition metal ions.

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

In one form of the above embodiment, the one or more transition metals are selected from the group consisting of cobalt, manganese and/or nickel.

In the case where the electronic waste further comprises one or more transition metal salts, it is further desirable that the leaching is alkaline leaching, and the leaching solution further comprises ammonia in an amount such that the pH of the leaching solution is about 8.5 to about 10.5. More preferably, the leaching solution further comprises ammonium chloride. Ideally, the ammonium chloride is present at a concentration of at least 1 g/L.

In one embodiment, the leaching is alkaline leaching.

In one form of the above embodiment, the leaching solution further comprises ammonia and/or ammonium chloride. Ideally, the amount of ammonia is sufficient to make the pH of the leaching solution about 8.5 to about 10.5. Ideally, the ammonium chloride is present at a concentration of at least 1 g/L.

In one embodiment, the electronic waste further comprises one or more nickel salts, preferably in the form of nickel oxide, and the leaching solution further comprises ammonia in an amount such that the pH of the leaching solution is about 8.5 to about 10.5, and wherein the leaching solution comprises at least copper ions, lithium ions, and nickel ions. Preferably, the pH is about 9. More preferably, the pH is up to about 10.

In one form of the above embodiment, the leaching solution comprises ammonia and ammonium sulfate, and the ratio of ammonia to ammonium sulfate is about 1:2 to about 1:20.

In one form of the above embodiment, the ratio of copper:nickel is about 2:1 to about 0.5:1.

In one form of the above embodiment, the method further comprises recovering copper and nickel from the leachate by solvent extraction. Ideally, the solvent extraction process comprises contacting the leachate with an extractant so that copper ions and nickel ions are adsorbed into the extractant to form an extractant loaded with copper and nickel, and separating the extractant loaded with copper and nickel from the leachate. More preferably, the method further comprises extracting copper ions and nickel ions from the extractant loaded with copper and nickel using an extractant, such as sulfuric acid, wherein nickel ions are selectively recovered at a first extractant concentration, and then copper ions are recovered at a second extractant concentration, wherein the first extractant concentration is less than the second extractant concentration.

In one embodiment, the electronic waste further comprises cobalt, and the leaching solution further comprises ammonia, wherein the amount of ammonia is such that the pH of the leaching solution is about 8.5 to about 10.5, and wherein the leaching solution comprises at least copper ions, lithium ions, and cobalt ions.

In one form of the above embodiment, the ratio of copper:cobalt is about 2:1 to about 0.5:1.

In one form of the above embodiment, the aforementioned method further comprises recovering copper ions from the leachate, and after removing the copper ions, precipitating cobalt from the leachate.

Ideally, the step of precipitating cobalt from the leachate includes precipitating cobalt sulfide from the leachate. In embodiments where nickel and/or manganese are present in the electronic waste, the step of precipitating cobalt from the leachate is performed after recovering manganese and/or nickel. That is, ideally, prior to the step of precipitating cobalt, the leachate is substantially free of copper, manganese and nickel. For example, the leachate contains copper and/or manganese and/or nickel at a concentration of 100 mg/L or less. More ideally, the concentration of each is 80 mg/L or less. Most ideally, the concentration of each is 60 mg/L or less. This is to minimize the co-precipitation of copper, manganese and nickel sulfides, thereby providing a higher purity cobalt product.

In one embodiment, the electronic waste further comprises manganese, and the leaching solution further comprises a leachate containing manganese, and the method further comprises: treating the leachate with an oxidizing agent to form a precipitate of manganese and provide a manganese-poor leachate containing copper ions and lithium ions; and separating the manganese precipitate from the manganese-poor leachate.

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

In one form of the above embodiment, the ratio of copper:manganese is about 2:1 to about 0.5:1.

In one embodiment, the electronic waste further comprises iron and aluminum, the solid slag comprises iron and aluminum, and the leachate is an iron-poor or aluminum-poor leachate, and/or the leachate substantially does not comprise iron or aluminum.

In one embodiment, the leachate contains iron and aluminum at a concentration of 100 mg/L or less, respectively. More preferably, the concentration is 80 mg/L or less, respectively. Most preferably, the concentration is 60 mg/L or less, respectively.

In one embodiment, the electronic waste contains copper element and one or more compounds of cobalt, lithium and nickel, wherein the leaching solution further contains ammonia, and the leaching solution contains cobalt ions, copper ions, lithium ions and nickel ions; after the step of separating the leaching solution from the solid residue, the method further comprises: Subjecting the leaching solution to a solvent extraction step to remove copper ions and nickel ions from the leaching solution and form a copper-poor and nickel-poor leaching solution; The aforementioned poor copper and poor nickel leaching solution is subjected to a sedimentation step to remove cobalt ions from the aforementioned poor copper and poor nickel leaching solution and form a poor cobalt, poor copper and poor nickel leaching solution; and Recovering lithium from the aforementioned poor cobalt, poor copper and poor nickel leaching solution, wherein, before the step of recovering lithium, the aforementioned leaching solution is subjected to an ammonia recovery step, so that during the process of recovering lithium, the aforementioned poor cobalt, poor copper and poor nickel leaching solution is substantially free of ammonia.

In one form of the above embodiment, the cobalt ions include Co ²⁺ ions, and before subjecting the leachate to the solvent extraction step, the method further includes treating the leachate with an oxidizing agent to oxidize the Co ²⁺ ions to Co ³⁺ ions.

In one embodiment, the electronic waste comprises copper and one or more compounds of cobalt, lithium, manganese and nickel, wherein the leachate further comprises ammonia, and the leachate comprises cobalt ions, copper ions, lithium ions, manganese ions and nickel ions; after separating the leachate from the solid residue, the method further comprises: treating the leachate with an oxidant to form a manganese precipitate and provide a manganese-poor leachate, wherein the manganese-poor leachate comprises Co ³⁺ ions; and separating the precipitate of manganese from the aforementioned manganese-poor leaching solution; subjecting the aforementioned manganese-poor leaching solution to a solvent extraction step to remove the copper ions and nickel ions from the aforementioned manganese-poor leaching solution and form a copper-poor, manganese-poor, and nickel-poor leaching solution; The above-mentioned poor copper, poor manganese, and poor nickel leachate is subjected to a sedimentation step to remove cobalt ions from the above-mentioned poor copper, poor manganese, and poor nickel leachate to form a poor cobalt, poor copper, poor manganese, and poor nickel leachate; and lithium is recovered from the above-mentioned poor cobalt, poor copper, poor manganese, and poor nickel leachate; wherein before the step of recovering lithium, the above-mentioned leachate is subjected to an ammonia recovery step, so that during the process of recovering lithium, the above-mentioned poor cobalt, poor copper, and poor nickel leachate is substantially free of ammonia.

In one embodiment, the aforementioned leaching solution further comprises ammonia, the aforementioned leaching solution is a first leaching solution, the aforementioned solid residue is a first solid residue, and after the step of separating the aforementioned first leaching solution from the aforementioned first solid residue, the aforementioned method further comprises: Leaching the solid residue with a second leaching solution comprising ammonium sulfate to provide a second leaching solution and a second solid residue; and Separating the aforementioned second leaching solution and the second solid residue; Leaching the aforementioned second solid residue with an acid to provide a third leaching solution and a third solid residue; Separating the aforementioned third leaching solution and the aforementioned third solid residue; and Mixing the aforementioned first leaching solution, the aforementioned second leaching solution and the aforementioned third leaching solution to form a mixed leaching solution.

In one embodiment of the above-mentioned embodiment, the electronic waste contains copper element and one or more compounds of cobalt, lithium, manganese and nickel, and the above-mentioned method includes recovering one or more of cobalt, copper, lithium, manganese and nickel from the mixed leachate.

In one embodiment, the aforementioned leaching solution is substantially free of acid, and/or contains substances without added acid. In some cases, the natural pH value of the leaching solution during the aforementioned leaching process is lower than 7. In this case, this is due to the acidic species produced during the aforementioned leaching process. Therefore, in an ideal form of the invention, any acid present in the leaching solution is generated during the leaching process from the electronic waste.

In one embodiment, the leaching solution contains substantially no organic compounds, for example, no monomers, oligomers, polymers, surfactants, organic leaching agents, organic acids, organometallic compounds, etc.

In one embodiment, the leaching solution is substantially free of biological material. For example, the leaching solution is free of vegetable, fruit or animal biological matter.

In one embodiment, the method comprises: leaching the electronic waste for the first time with a first leaching solution to provide a first leachate and a solid residue, and leaching the leach residue with a leaching solution containing ammonium sulfate in the presence of an oxidant to provide a leachate containing copper ions and lithium ions and a solid residue.

It is understood by those skilled in the art that there may be an additional leaching step between the first leaching and the step of leaching the leached residue. For example, a second leaching solution may be used to perform a second leaching to produce a second leachate and a second leached residue, and the step of leaching the leached residue is one of the steps of leaching the second leached residue.

The first leaching (and the second leaching in various embodiments) can be, for example, an acid leaching, an alkaline leaching, etc. However, ideally, the first and/or second leaching solutions comprise one or more of ammonia, ammonium sulfate, and ammonium chloride. In embodiments thereof, the first and/or second leaching solutions comprise, consist of, consist essentially of, or consist of: (1) ammonia and ammonium chloride, (2) ammonia and ammonium sulfate, (3) ammonium sulfate and ammonium chloride, and (4) ammonia, ammonium chloride, and ammonium sulfate. In embodiments, the leachate is mixed with the first leachate (and the second leachate in embodiments including a second leaching step) to form a mixed leachate from which copper and lithium can be recovered, while cobalt, manganese, and nickel (if present) are recovered according to the above method.

The reference to any prior art in this specification does not imply an admission or representation that the prior art constitutes part of the common knowledge in any jurisdiction, or that a person of ordinary skill in the art could reasonably expect the prior art to be understood, regarded as relevant and/or combined with other prior arts.

As used herein, the use of the term "comprising" and variations of the term, such as "comprising", "comprises" and "comprised", is not intended to exclude additional additives, components, integers or steps, unless the context requires otherwise.

The present invention generally relates to a method for recovering precious metals, particularly lithium, from electronic waste containing the element copper and one or more lithium-containing salts.

The method comprises leaching the electronic waste with ammonium sulfate, during which the copper element is oxidized to copper ions, thereby providing a source of electrons to act as a reducing agent and thereby generating soluble lithium ions from the lithium-containing salt. If transition metals such as cobalt, manganese and nickel are present in the electronic waste, for example as a component of the lithium-containing salt or as a metal oxide, these are also reduced to water-soluble ions. Various soluble metal ions, especially lithium, can be selectively recovered as products. The ammonium sulfate can also be recovered and reused for further leaching.

The aforementioned method is particularly suitable for recovering lithium from spent lithium-ion batteries, in particular battery fragments (whether a single type of battery or mixed battery fragments from different lithium-ion batteries). The aforementioned method can be advantageously used on raw battery fragments, that is, battery fragments that have not been subjected to pre-treatment such as copper extraction and/or calcination (as opposed to black material). As non-limiting examples, the aforementioned method can be applied to extract ions of cobalt, copper, lithium, manganese and nickel, based on the chemical properties of the battery or mixed battery in the battery fragment.

In a preferred form of the present invention, the electronic waste includes a lithium ion battery, and the lithium ion battery includes a lithium metal oxide or a lithium metal phosphate, which discloses, without limitation, that the lithium ion battery includes nickel manganese cobalt (NMC), lithium cobalt oxide (LCO), lithium ion manganese oxide (LMO), lithium iron phosphate (LFP), and lithium nickel cobalt aluminum oxide (NCA) batteries and mixtures thereof. Generally, in such batteries, the lithium element exists in the form of one or more lithium salts such as LiMO ₂ and LiMPO ₄ , wherein M is a transition metal and/or LiNi _x Co _y Al _z O ₂ , wherein x + y + z = 1. The aforementioned electronic waste may further include other electronic waste, such as printed circuit boards, etc.

Without wishing to be bound by theory, the inventors believe that the aforementioned ammonium sulfate leaching promotes the oxidation-reduction of copper, which ultimately provides a source of electrons and soluble copper salts, and, in the process, reduces lithium metal salts (such as those mentioned above) to release lithium ions into solution, and optionally releases copper, cobalt, manganese and nickel ions, depending on the chemical properties of the lithium ion battery in the battery fragments. The aforementioned leaching is selective because cheap metals such as iron and aluminum may be present in the electronic waste, and the cheap metals are essentially retained in the solid residue together with the cheap phosphate compounds.

More specifically, during the ammonium sulfate leaching process, copper metal is oxidized to Cu(I). The aforementioned Cu(I) is oxidized to Cu(II) by a redox reaction with a lithium metal salt or other transition metal salt, thereby forming metal salts of soluble ions of lithium and/or cobalt, manganese and nickel (if present). In the absence of a copper metal source as a reducing agent, or a balanced lithium metal salt and/or other transition metal salt as an oxidant to convert Cu(I) and Cu(II), the aforementioned redox reaction will stop. Generally, the aforementioned method provides sufficient oxidant (in the form of lithium metal salt and/or other transition metal salt) and sufficient copper to enable the reaction to proceed to the end. If the oxidant in the form of lithium metal salt and/or other transition metal salt is insufficient, additional oxidant may be added, such as air, hydrogen peroxide, hypochlorite, etc.

The inventors have also found that it is useful to introduce ammonium chloride into the leaching process or as a component of the leaching solution, as this increases the stability of the Cu(I) ions in the solution, thereby making the leaching more effective and efficient.

The resulting leachate typically contains at least copper and lithium ions and, depending on the composition of the electronic waste, may additionally contain cobalt, manganese and nickel ions. When present, the cobalt, manganese and nickel ions may be selectively recovered according to the aforementioned method of the present invention.

In the case where the leachate contains copper ions and lithium ions, the copper ions can be recovered by solvent extraction. That is, the leachate is contacted with an extractant to recover copper ions from the leachate, forming an extractant loaded with copper. The extractant can then be extracted with a stripping agent (such as sulfuric acid) to recover copper, such as in the form of a copper sulfate solution.

The substantially copper-free leachate can be further processed to recover ammonium sulfate and lithium. The inventors have discovered that lithium ammonium sulfate can be crystallized from the leachate, for example, by concentrating the leachate, for example, by evaporating water from the leachate to crystallize the lithium ammonium sulfate. The lithium ammonium sulfate can then be recovered by a solid-liquid separation process (e.g., filtration, centrifugation, etc.), followed by thermal decomposition into lithium sulfate crystals, ammonia and sulfur trioxide gas. The sulfur trioxide gas can react with ammonia and water to regenerate ammonium sulfate.

If other transition metal ions are present in the leachate, such as cobalt, manganese and nickel ions, these ions may be selectively recovered prior to recovering lithium. In embodiments where cobalt, manganese and nickel are present, it is desirable to recover manganese from the leachate followed by cobalt before recovering copper and nickel.

In embodiments where manganese is present, manganese ions may be recovered by oxidizing the manganese to manganese oxides such as _{Mn2O3 , Mn3O4} and/or _MnO2 (but not MnO), with air being a suitable oxidant. If Co(II) ions are present during the oxidation process, such ions will be oxidized to Co(III) ions. In order to prevent _CoO precipitation, in addition to oxidizing the Co(II) ions to Co(III) ions, the aforementioned manganese recovery step is ideally carried out in the presence of ammonia, so that, as described above, ammonia forms a stable soluble sulfate complex with the cobalt ions, thereby reducing CoO precipitation in the aforementioned oxidation treatment step. The cobalt ions can then be recovered by precipitation with various salts such as carbonates and/or sulfides.

In embodiments including nickel and/or cobalt, the inventors have also found that it is useful to introduce ammonia during the leaching process or as a component of the leaching solution, because ammonia forms a complex with nickel and/or cobalt to form a stable soluble nickel and/or cobalt ammonia sulfate, particularly in the pH range of 9 to 10. This facilitates the selective extraction and recovery of nickel and/or cobalt.

In embodiments where the leachate contains both nickel and cobalt ions, it is desirable to extract copper and nickel ions simultaneously from the leachate, followed by recovery of cobalt ions and then recovery of lithium ions. However, one of ordinary skill in the art will appreciate that these metal ions may be extracted or otherwise recovered from the leachate in a different order, and/or that other metal ions may be recovered from the leachate at an intermediate step prior to or possibly after lithium recovery.

Nickel ions can be extracted simultaneously with copper ions by solvent extraction. To facilitate this, the aforementioned method can include an upstream oxidation step of oxidizing cobalt ions to Co(III). This prevents the recovery of cobalt during solvent extraction, thereby avoiding poisoning of the extractant by Co(II) ions. Then, before extracting the copper ions, the nickel ions can be selectively extracted from the extractant with a stripping agent. The ideal extractant is sulfuric acid, in which case the nickel ions can be extracted at a relatively lower sulfuric acid concentration than the copper ions, thereby allowing the selective recovery of nickel and copper ions. The cobalt can then be recovered from the permeate by precipitation (e.g., co-precipitation with the sulfide).

If ammonia is present, it can be recovered before recovering the lithium. Ammonia can be stripped from the leachate by steam.

If ammonium chloride is present, it will remain in the leachate and can be recovered (in the form of lithium ammonium sulfate as described above) after the lithium is recovered from the leachate.

The present invention will be described below in conjunction with the embodiments of the present invention, which are illustrative in nature and should not be construed as restrictive. [Implementation 1]

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

The method comprises an initial leaching step in which lithium-ion battery waste (possibly mixed with other electronic waste sources) is alkaline leached with a first leaching solution comprising ammonium sulfate. In this embodiment, the first leaching solution also comprises ammonia and ammonium chloride, both of which have been found to enhance the leaching process. Ammonia helps to form stable soluble complexes of nickel and cobalt, and ammonium chloride helps to stabilize Cu(I), thereby increasing the effectiveness of the leaching. The leaching is carried out at atmospheric pressure and ambient temperature. However, the leaching can be carried out at an elevated temperature, for example, at a temperature below the boiling point of the leaching solution.

The aforementioned alkaline leaching oxidizes the copper element contained in the lithium ion battery into soluble copper ions, which in turn provide a source of electrons to reduce or release the cobalt, lithium and nickel ions contained in the battery. Therefore, the aforementioned leaching results in the formation of a leachate containing soluble ions of copper, cobalt, lithium and nickel and a solid slag. The inventors have found that a large portion of the cobalt, nickel, copper and lithium is leached into the solution, for example, greater than about 90% of nickel, copper and cobalt, and greater than about 70% of lithium. Similarly, most of the aluminum and iron contained in the battery are retained in the solid slag, for example, greater than about 99% of the aluminum and iron.

The aforementioned leachate may be subjected to a solvent extraction step to extract copper and/or nickel. The aforementioned solvent containing copper and/or nickel may then be separated from the mixed leachate, and copper and/or nickel may then be recovered from the solvent. Copper and nickel may be recovered from the solvent by extraction with a stripping agent such as sulfuric acid. Typically, nickel may be selectively extracted with a lower residual acid concentration than copper, such as in a pH range of about 1 to 4, followed by extraction of copper by increasing the acid concentration, such as 50 g/L or more of _H2SO4 . This two-stage extraction allows for the selective recovery of copper and _nickel in their respective streams.

The leachate may then be further treated to recover the cobalt. In this embodiment, the cobalt is recovered by a cobalt precipitation process, wherein the leachate is treated with a sulfide, such as hydrogen sulfide or ammonium sulfide, to precipitate cobalt sulfide. The cobalt sulfide may then be recovered from the mixed leachate using any solid-liquid separation method known to those of ordinary skill in the art, such as filtration.

The aforementioned leachate has now been substantially free of cobalt, copper and nickel and can be further processed to recover ammonia, ammonium salt and lithium.

Ammonia is stripped from the aforementioned leachate, and the recovered ammonia is recycled and reused as part of the first leachate. The lithium in the leachate is usually in the form of lithium sulfate. The lithium sulfate can be crystallized with ammonium sulfate (for example, by an evaporation process) in the form of lithium ammonium sulfate and separated from the aforementioned leachate. The aforementioned lithium ammonium sulfate can then be thermally treated to decompose the lithium ammonium sulfate into lithium sulfate solid, ammonia gas and sulfur trioxide gas. The aforementioned ammonia and sulfur trioxide gas can be captured and reacted with water (for example, in a wet scrubber) to form ammonium sulfate, which can be recycled to the first and/or second leaching steps. [Implementation Method 2]

This embodiment describes a method for recovering metals from a feed containing one or more lithium ion battery types. In this particular embodiment, the feed contains copper metal and metal oxides of at least lithium and nickel.

The method comprises an initial leaching step in which lithium-ion battery waste (possibly mixed with other electronic waste sources) is subjected to alkaline leaching with a first leaching solution comprising ammonium sulfate. In this particular embodiment, the first leaching solution also comprises ammonia, which has been found to enhance the leaching process by promoting the formation of stable soluble nickel and cobalt complexes. The leaching is carried out at atmospheric pressure and ambient temperature. However, the leaching can be carried out at an elevated temperature, for example, at a temperature below the boiling point of the leaching solution.

The alkaline leaching oxidizes the copper element contained in the lithium ion battery into soluble copper ions, thereby providing an electron source to reduce or release the nickel and lithium ions contained in the battery. Therefore, the leaching results in the formation of a first leachate containing soluble ions of copper, lithium and nickel and a first solid slag.

Then, the first leachate and the first solid residue are separated.

The first solid slag contains cheap materials such as iron and aluminum, but depending on the type of lithium ion battery waste, the solid slag may also contain residual lithium and nickel compounds.

The amounts of lithium and nickel may be sufficient to warrant further processing and recovery of these metals. If so, the first solid residue may be subjected to a further leaching step with a second leaching solution comprising ammonium sulfate and, ideally, ammonium chloride. The inventors have found that ammonium chloride advantageously stabilizes Cu(I) ions. The second leaching is conducted at atmospheric pressure and ambient temperature. However, as described above, the second leaching may be conducted at an elevated temperature, such as a temperature below the boiling point of the leaching solution. The second leaching may be an oxidative leaching. That is, an oxidizing agent such as air, hydrogen peroxide, hypochlorite, etc. may be used during the leaching process to assist in the recovery of the metals. If the redox half-cell potential is below 100 mV, as is the case with typical LFP battery waste feeds, then the oxidant is assisting or enhancing the leaching process.

The second leaching provides a second leachate containing soluble ions of lithium and nickel and a second solid residue.

Then, the second leachate and the second solid residue are separated.

The first and second leachates are then mixed to form a mixed leachate, which is then subjected to a plurality of steps to selectively recover copper, lithium and nickel.

The mixed leachate may be subjected to a solvent extraction step to extract copper and/or nickel. In an alternative embodiment where the leachate contains manganese ions, the leachate is first treated to remove manganese, such as by an oxidation and precipitation process as described above. Additionally, in embodiments where the leachate contains cobalt ions, the leachate is first subjected to an oxidation process (e.g., during manganese recovery) to convert the cobalt ions to Co(III) to prevent poisoning of the extractant solvent by the cobalt ions. In any case, the copper and/or nickel-containing solvent may then be separated from the mixed leachate, and the copper and/or nickel may then be recovered from the solvent. Copper and nickel can be recovered from the solvent by extraction with a stripping agent such as sulfuric acid. Typically, nickel can be selectively extracted with a lower residual acid concentration than copper, for example, in the pH range of about 1 to 4, followed by extraction of copper by increasing the acid concentration (e.g., to greater than about 50 g/L _H2SO4 ). This two-stage extraction allows copper and _nickel to be selectively separated.

The aforementioned mixed leachate has now been substantially free of copper and nickel and can be further processed to recover ammonia, ammonium salt and lithium.

Ammonia is stripped from the leachate and the recovered ammonia is circulated and reused as part of the first leachate. The lithium in the leachate is usually in the form of lithium sulfate. The lithium sulfate can be crystallized with ammonium sulfate (e.g., by an evaporation process) in the form of lithium ammonium sulfate and separated from the leachate. The lithium ammonium sulfate can then be thermally treated to decompose the lithium ammonium sulfate into lithium sulfate solid, ammonia gas and sulfur trioxide gas. The ammonia and sulfur trioxide gas can be captured and reacted with water (e.g., in a wet scrubber) to form ammonium sulfate, which can be recycled to the first and/or second leaching steps.

FIG1 shows a process flow diagram of the method according to the above-described embodiment. The method of FIG1 describes the recovery of copper product 18 and lithium product 30. In this embodiment, feed stream 1 undergoes a pretreatment process, such as crushing 100, to make feed stream 1 suitable for further processing, which is typically <5 mm. The resulting crushed feed stream 2 is then passed into an alkaline leaching loop 110, where it is reacted with a solution comprising ammonia, ammonium sulfate with/without ammonium chloride 19, and ammonia top-up 3 and 22 to dissolve copper. The aforementioned alkaline leaching loop is operated under conditions such as about 50° C., atmospheric pressure, pH about 9.0, and about 10% solids. The alkaline leaching slurry 4 is subjected to a solid-liquid separation step 120, such as using a concentrator or a plurality of concentrators with a washing function, and the ammonia leaching solution 6 is introduced into the solvent extraction loop 160.

The thickener underflow 5 is introduced into the ammonium sulfate leaching circuit 130, where it reacts with the solution 7 containing the ammonium sulfates 24 and 32 and the ammonium sulfate supplement. Air 8 is sprayed into the aforementioned leaching circuit 130. The aforementioned ammonium sulfate leaching is operated at about 100°C, about Eh 120mV (Ag/AgCl electrode), and a solid content of about 10%. The aforementioned ammonium sulfate leaching effluent 9 is introduced into the thickener 140. The thickener underflow 11 is introduced into the filter 150, and the thickened slurry is filtered by the filter. The resulting filter cake is washed with water 12, and the filter liquor and the washed filter liquor are mixed with the thickener overflow 10 and the ammonia leachate 6.

The pregnant leach liquor is introduced into a copper solvent extraction loop 160 where it reacts with a copper extractant, such as a commercially available oxime extractant, such as LIX84I™. Copper is loaded onto the aforementioned copper extractant and the copper loaded extractant 14 is separated from the raffinate 19. The aforementioned loaded extractant 14 reacts with dilute sulfuric acid 16 or an anodic electrolyte, the anodic electrolyte coming from the copper electrolytic precipitation stage 180 of the copper extraction stage 170, to prepare a loaded extraction solution 15, the loaded extraction solution 15 comprising copper and a copper-poor extractant. The extracted organic matter (not shown) is recycled (not shown) to the extraction loop 160 to extract more copper. In the copper electrolytic precipitation stage 180, the copper product 18 is recovered from the copper-loaded extraction solution 15.

The copper-poor raffinate 19 containing ammonia and ammonium sulfate is introduced into the ammonia leaching loop 110 to recover more metal. The remaining filtrate 29 is introduced into the ammonia recovery loop 190, in which steam 21 is used to strip ammonia 22. The ammonia 22 recovered in this process is reused, in particular, for example, in the ammonia leaching 110.

The ammonia-free solution 24 is introduced into the ammonium sulfate leaching 130 and the crystallizer 200, in which the condensate 25 is removed by forced evaporation and the lithium ammonium sulfate 26 is crystallized. The discharge of the crystallizer is separated into solid and liquid using a centrifuge 210, and the concentrated solution 27 is introduced into the ammonium sulfate leaching 130. The lithium ammonium sulfate 28 is calcined in the kiln 220, and the solid (lithium sulfate 30) is collected in the kiln 220 for sale, and the exhaust gas 29 is collected in the wet scrubber using the washing water 31 to recover the ammonium sulfate solution 32. The solution is introduced into the ammonium sulfate leaching 130. 〔Implementation Method 3〕

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

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

The alkaline leaching oxidizes the copper element contained in the lithium ion battery into soluble copper ions, and reduces or otherwise releases nickel, cobalt, manganese and lithium ions contained in batteries such as nickel manganese cobalt (NMC), lithium cobalt oxide (LCO) and lithium ion manganese oxide (LMO). Therefore, the leaching forms a first leachate containing soluble ions of cobalt, copper, lithium, manganese and nickel and a first solid slag.

Then, the first leachate and the first solid residue are separated.

The first solid slag contains cheap materials such as iron and aluminum, but may also contain residual compounds of cobalt, lithium, manganese and nickel depending on the type of lithium-ion battery waste. For example, when the feed contains lithium iron phosphate (LFP) and lithium nickel cobalt aluminum oxide (NCA) batteries, some cobalt, lithium and nickel will remain in the first solid slag.

The amounts of cobalt, lithium, manganese and nickel may be sufficient to make further recovery of these metals economically feasible and therefore desirable. If so, the first solid residue may be subjected to a further leaching step with a second leaching solution comprising ammonium sulfate and, ideally, ammonium chloride. The second leaching is conducted at atmospheric pressure and ambient temperature. However, as described above, the second leaching may be conducted at an elevated temperature, such as a temperature below the boiling point of the leaching solution. The second leaching may be an oxidative leaching. That is, an oxidizing agent such as air, hydrogen peroxide, hypochlorite, etc. may be used during the leaching process to assist in the recovery of the metals. Typically, for feeds containing NCA and/or NMC battery materials, no oxidant is required, as the cobalt, nickel and manganese are present in sufficient amounts to provide a sufficiently high redox half-cell potential of >100 mV. However, if the aforementioned redox half-cell potential is below 100 mV, as is the case with typical LFP battery waste feeds, then an oxidant assists or enhances the aforementioned leaching process.

The second leaching provides a second leachate containing soluble ions of cobalt, lithium, manganese and nickel and a second solid residue.

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

In order to further recover these metals, the second solid residue is subjected to a size separation treatment to separate 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 leaching, such as with sulfuric acid, to provide a third leachate containing cobalt, lithium, manganese and nickel ions and a third solid residue. The third leaching is carried out at atmospheric pressure and ambient temperature. However, as described above, the third leaching can be carried out at an elevated temperature, such as a temperature below the boiling point of the leaching solution.

Then, the third leachate and the third solid residue are separated.

It should be understood that the aforementioned third acid leaching step is omitted in an alternative embodiment.

Aluminum, iron and phosphates are not extracted in significant amounts and are usually retained in the first, second and/or third solid residues. As such, the leaching process is selective for higher value metals such as copper, cobalt, lithium, manganese and nickel.

The first, second and third leachates may then be mixed to form a mixed leachate, and then a plurality of steps may be performed to selectively recover cobalt, copper, lithium, manganese and nickel.

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 _Mn2O3 , _Mn3O4 and/or _MnO2 (but not MnO). The inventors have discovered that, in the case where the aforementioned leachate also contains _cobalt ions, the presence of ammonia is important for complexing with the cobalt ions to retain them in the form of soluble Co(III) ions and prevent the formation of CoO precipitate. The manganese oxide precipitate can then be recovered from the combined leachate using any solid-liquid separation method known to those of ordinary skill in the art, such as filtration.

The mixed leachate may then be subjected to a solvent extraction step to extract copper and/or nickel. The copper and/or nickel loaded solvent may then be separated from the mixed leachate, followed by recovery of copper and/or nickel from the solvent. Copper and nickel may be recovered from the solvent by extraction with a stripping agent such as sulfuric acid. Typically, nickel may be selectively extracted with a lower residual acid concentration than copper, such as in the range of about pH 1 to 4, followed by extraction of copper by increasing the acid concentration (e.g., to about 50 g/L or more of _H2SO4 ). This two-stage extraction allows for selective separation of copper and _nickel .

In an alternative embodiment, copper and nickel may be recovered before manganese.

The mixed leachate may then be further treated to recover the cobalt. In this embodiment, the cobalt is recovered by a cobalt precipitation process, whereby the mixed leachate is treated with a sulfide such as hydrogen sulfide gas or ammonium sulfide to precipitate cobalt sulfide. The cobalt sulfide may then be recovered from the mixed leachate using any solid-liquid separation method generally known to those of ordinary skill in the art, such as filtration.

The aforementioned mixed leachate, now substantially free of cobalt, copper, manganese and nickel, may be further processed to recover ammonia, ammonium salts and lithium.

Ammonia is stripped from the leachate, and the recovered ammonia is recycled and reused as part of the first leachate. The lithium in the leachate is usually in the form of lithium sulfate. The lithium sulfate can be crystallized with ammonium sulfate (e.g., by an evaporation process) in the form of lithium ammonium sulfate and separated from the leachate. The lithium ammonium sulfate can then be thermally treated to decompose the lithium ammonium sulfate into lithium sulfate solid, ammonia gas and sulfur trioxide gas. The ammonia and sulfur trioxide gas can be captured and reacted with water (e.g., in a wet scrubber) to form ammonium sulfate, which can then be recycled to the first and/or second leaching steps.

The above process is described in more detail with reference to Figure 2. Figure 2 shows a schematic diagram of the process flow of the method of the present invention according to the above embodiment.

The process shown in 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 undergoes a pre-treatment process, such as crushing 100 to <5 mm, such as <1 mm, to make feed stream 1 suitable for further processing. The resulting crushed feed stream 2 is then sent to an alkaline leaching loop 110, where it reacts with a solution containing ammonia, ammonium sulfate with/without ammonium chloride 39, and ammonia supplements 3 and 40 to dissolve metal species. Conditions in the alkaline leach loop 110 include about 5-10% solids, about 50°C, atmospheric pressure, a residence time of about 12 hours, ammonia at a pH of about 9, about 200 g/L ammonium sulfate, and about 20 g/L ammonium chloride (if present).

The alkaline leaching slurry 4 obtained is subjected to a solid-liquid separation step 120, for example using a concentrator or a plurality of concentrators with a washing function, and the ammoniacal leaching solution 6 is introduced into a manganese oxide precipitation circuit 180.

The concentrator underflow 5 is introduced into the ammonium sulfate leaching loop 130 where it contacts a solution containing ammonium sulfate 47 and an ammonium sulfate supplement 7. The conditions in the ammonium sulfate leaching loop 130 include about 5-10% solids, about 100-105° C., atmospheric pressure, a residence time of about 4-12 hours, about 200 g/L of ammonium sulfate and 20 g/L of ammonium chloride.

The ammonium sulfate leach effluent 8 is introduced into a screen 140, for example, between 75 and 500 μm, for example, about 180 μm, to separate the coarse and fine fractions of particles. The coarse fraction 9 is stored and the fine fraction 10 is introduced into a concentrator 150. The concentrator overflow, for example, ammonium sulfate leachate 11, is introduced into a manganese oxide precipitation circuit 180.

The concentrator underflow 12 is introduced into the acid leaching loop 160 where it reacts with sulfuric acid 13. The conditions of the acid leaching loop 160 include a temperature in the range of about 20-100°C, such as 70°C, a pH of less than about 3, such as about pH 1.5, a residence time of about 4-12 hours, 30% solids and 98% acid additives.

The acid leach effluent 14 is filtered 170 and the solids are washed to produce a stored leach residue 15 and an acid leachate 17 which is introduced into a manganese oxide precipitation circuit 180 .

Leaching solutions 6, 11 and 17 are introduced into a manganese oxide precipitation circuit 180, where air 18 is injected into the solution to force the manganese oxide to precipitate. The precipitation slurry 19 is subjected to solid-liquid separation by thickening and filtering 190. The manganese product 20 is washed and stored.

The rich leached solution after manganese precipitation 21 is introduced into a copper and nickel solvent extraction loop 200 where it is reacted with a copper and nickel extractant, such as a commercially available oxime extractant, such as LIX84I™. Copper and nickel are loaded onto the copper extractant, and the loaded extractant 23 is separated from the raffinate 22. In the nickel extraction stage 210, the loaded extractant 23 is reacted with dilute sulfuric acid 24, such as 150 g/L sulfuric acid, to produce a loaded extraction solution containing nickel 25 and a nickel-poor extractant 28. In the copper extraction stage 220, the nickel-poor extractant 28 is reacted with a dilute sulfuric acid solution 29, such as 200 g/L sulfuric acid, to produce a copper-loaded extraction solution 30. The extracted organic matter (not shown) is circulated (not shown) to the extraction loop 200 to extract more copper and nickel. The nickel product 27 (apparently in the form of nickel sulfate) is recovered from the nickel-loaded extraction solution 25 in the nickel crystallization stage 230. In the copper electrolysis stage 240, the copper product 32 (apparently in the form of copper sulfate) is recovered from the copper-loaded extraction solution 30.

The copper- and nickel-poor raffinate 22 is introduced into the cobalt recovery loop 250, and a precipitant, such as hydrogen sulfide gas 33, is added to the cobalt recovery loop 250 to promote the precipitation of cobalt sulfide. The obtained slurry 34 is separated into solid and liquid by, for example, a concentrator and a filter 260, and washed with water 35 to produce a cobalt product 37.

Most of the filtrate 39 containing ammonia and ammonium sulfate is introduced into the ammonia leaching circuit 110 to recover more metals. The remaining filtrate 38 is introduced into the ammonia recovery circuit 270, where steam 41 is used to strip ammonia 40. The recovered ammonia 40 is reused in the process, in particular, for example, in the ammonia leaching 110.

The ammonia-free solution 42 is introduced into the ammonium sulfate leaching 130 and also introduced into the crystallizer 280, where the condensate 43 is removed by forced evaporation and the lithium ammonium sulfate 46 is crystallized. The crystallizer discharge is subjected to solid-liquid separation using a centrifuge 290, and the concentrated solution 45 is introduced into the ammonium sulfate leaching 130. The lithium ammonium sulfate 46 intermediate is calcined in the kiln 300. In the kiln 300, the solid lithium sulfate 48 is collected for sale, and the exhaust gas 47 is collected in a wet scrubber using wash water 49 to recover the ammonium sulfate solution 50. [Example] [Example 1]

This example discloses a single-stage alkaline leaching of raw lithium nickel manganese cobalt oxide 622 (NMC622) battery scrap using a leaching solution comprising ammonium sulfate, ammonia and ammonium chloride.

The NMC battery scrap contained 22.9wt% copper, 12.5wt% nickel, 4.9wt% cobalt, 6.2wt% manganese and 2.94wt% lithium in elemental amounts. The copper element was present in sufficient amounts to provide a redox potential of less than -150mV (Ag/AgCl electrode) during leaching.

The NMC battery fragments were reacted with a leaching solution containing 169 g/L ammonium sulfate, 46 g/L ammonia and 14.5 g/L ammonium chloride with a solid loading of 3.8 wt%. The leaching was carried out at a pH of 9.5, atmospheric pressure and a temperature of 50°C for 2 hours.

The extraction rates of nickel, cobalt, copper, lithium and manganese in the leaching solution were 97.5%, 96.4%, 99.3%, 95.5% and 96.1%, respectively.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover nickel, cobalt, copper, lithium and manganese from the leachate. Similarly, the method provided by the present invention can be used to recover the aforementioned ammonium sulfate, ammonia and ammonium chloride for repeated use. [Example 2]

This example discloses a three-stage leaching of a mixed feed of raw lithium nickel manganese cobalt oxide 622 (NMC622), lithium nickel manganese cobalt oxide 811 (NMC811), lithium nickel cobalt aluminum oxide (NCA) and lithium iron phosphate (LFP) battery scrap using a leaching solution comprising ammonium sulfate, ammonia and ammonium chloride.

An equal weight mixture of NMC811, NMC622, NCA and LFP battery fragments was prepared, the equal weight mixture containing 7.01wt% copper, 14.5wt% nickel, 2.48wt% cobalt, 2.16wt% manganese and 2.69wt% lithium. The copper element was present in an amount sufficient to provide a redox potential of less than -150mV (Ag/AgCl electrode) during leaching.

First, the battery fragment mixture was alkaline leached in a solution containing 215g/L ammonium sulfate, 105g/L ammonia and 21g/L ammonium chloride with a solid content of 9.8wt%. The leaching was carried out for 6 hours at a pH range of 9.4-9.9, atmospheric pressure and 50°C.

The extraction rates of nickel, cobalt, copper, lithium and manganese in the leaching solution were 37.6%, 57.6%, 81.5%, 47.8% and 67.9% respectively. The above metals were mainly extracted from NMC622 and NMC811 batteries.

The solid residue of the first leaching was found to contain 1.46 wt % copper, 10.2 wt % nickel, 1.19 wt % cobalt, 0.78 wt % manganese and 1.59 wt % lithium.

The solid residue was separated from the leachate and subjected to a second leaching using a solution containing 343 g/L of ammonium sulfate and 34 g/L of ammonium chloride at a solid loading of 6.9 wt%. The leaching was conducted in a solution such that the natural pH value was in the range of 5.1 to 5.3 and the natural redox potential was 165 mV (Ag/AgCl electrode). The leaching was conducted at atmospheric pressure and 100°C for 6 hours.

The extraction rates of nickel, cobalt, copper, lithium and manganese were 59.4%, 82.2%, 33.8%, 94.3% and 94.7% respectively. Except for nickel, all other metals were extracted from all types of batteries. Nickel was mainly extracted from materials NMC811 and NMC622, which were not leached from materials NMC811 and NMC622 in the previous alkaline leaching.

The extraction rates of nickel, cobalt, copper, lithium and manganese in the leaching solutions of the two leaching stages were 74.7%, 92.5%, 87.7%, 97.0% and 98.3% respectively.

The solid residue from the second leaching, particularly steel and aluminum foil, was initially screened at 180 microns to remove coarse material. The screened material contained 1.27 wt% copper, 5.44 wt% nickel, 0.28 wt% cobalt, 0.95 wt% manganese and 0.12 wt% lithium.

The solid residue was re-slurried in water to 30% solids, followed by addition of sulfuric acid to a target pH of 1.50. After leaching for 6 hours at 70°C, the extraction yields 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 the equivalent pure sulfuric acid process (>1200kg/t).

The recovery rates of nickel, cobalt, copper, lithium and manganese in all three leaching steps of the leachate, including metal losses associated with screening, were 96.8%, 98.2%, 97.7%, 98.6% and 93.0% respectively.

The aforementioned leachates from the three leaching steps can be mixed and then treated using the method provided by the present invention to selectively recover nickel, cobalt, copper, lithium and manganese. Similarly, the aforementioned ammonium sulfate, ammonia and ammonium chloride can be recovered using the method provided by the present invention for repeated use. [Example 3]

This example discloses the oxidative leaching of raw lithium iron phosphate (LFP) battery scrap using a single-stage aqueous leaching solution of ammonium sulfate and ammonium chloride.

Calculated as elements, the LFP battery fragments contained 6.7wt% copper and 1.99wt% lithium.

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

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

The extraction rate of copper in the leaching solution was 83.4%, and the extraction rate of lithium was 92.5%. The total iron extracted was only 0.5%.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover copper and lithium from the leachate. Similarly, the method provided by the present invention can be used to recover ammonium sulfate and ammonium chloride for reuse. [Example 4]

This example discloses the leaching of raw lithium nickel manganese cobalt oxide 811 (NMC811) battery scrap using a single-stage aqueous leaching solution of ammonium sulfate and ammonium chloride.

Calculated by elements, the NMC811 battery fragments contained 2.46wt% copper, 22.2wt% nickel, 2.72wt% cobalt, 1.72wt% manganese and 2.83wt% lithium.

The NMC811 battery fragments were reacted with an aqueous leachate solution containing 355 g/L ammonium sulfate and 17.7 g/L ammonium chloride at a solid loading of 4.0 wt%. Copper metal was additionally added in an amount of 250 kg/t, which may be introduced in the form of electronic waste, such as printed circuit boards.

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

The extraction rates of copper, nickel, cobalt, manganese and lithium in the leaching solution were 60.1%, 67.0%, 79.3%, 94.8% and 95.5%, respectively.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover copper, nickel, cobalt, manganese and lithium from the leachate. Similarly, the method provided by the present invention can be used to recover ammonium sulfate and ammonium chloride for repeated use. [Example 5]

This example discloses the leaching of raw lithium nickel cobalt aluminum oxide (NCA) battery scrap using a single-stage leaching aqueous solution comprising ammonium sulfate and ammonium chloride.

In terms of elements, the NCA battery fragments contain 0.95wt% copper, 24.3wt% nickel, 2.77wt% cobalt, 0.02wt% manganese and 3.20wt% lithium ions.

The NCA battery fragments were reacted with an aqueous leachate solution containing 355 g/L ammonium sulfate and 17.7 g/L ammonium chloride at 4.0 wt% solid loading. Copper metal was additionally added in an amount of 250 kg/t, which could be introduced in the form of electronic waste, such as printed circuit boards, etc.

Leaching was carried out at a natural pH range of 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.

The extraction rates of copper, nickel, cobalt, manganese and lithium in the leaching solution were 87%, 33.4%, 58.9%, 58.2% and 94.6%, respectively.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover copper, nickel, cobalt, manganese and lithium from the leachate. Similarly, the method provided by the present invention can be used to recover ammonium sulfate and ammonium chloride for repeated use. [Example 6]

This example discloses alkaline leaching of raw lithium-ion manganese oxide (LMO) battery scrap using a single-stage aqueous leaching solution comprising ammonia, ammonium sulfate, and ammonium chloride.

The LMO battery fragments contained 3.28 wt% copper, 3.65 wt% nickel, 1.24 wt% cobalt, 27.9 wt% manganese and 2.52 wt% lithium, calculated on an elemental basis.

The LMO battery fragments were reacted with an aqueous leachate solution containing 45 g/L ammonia, 180 g/L ammonium sulfate and 18 g/L ammonium chloride at a solid loading of 4.0 wt%. Copper metal was additionally added in an amount of 250 kg/t, which could be introduced in the form of electronic waste, such as printed circuit boards.

Leaching was carried out at a natural pH range of 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.

The extraction rates of copper, nickel, cobalt, manganese and lithium in the aforementioned leaching solution were 84.0%, 89.7%, 93.3%, 71.8% and 97.3%, respectively.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover copper, nickel, cobalt, manganese and lithium from the leachate. Similarly, ammonia, ammonium sulfate and ammonium chloride can be recovered for repeated use using the method provided by the present invention. [Example 7]

This example discloses alkaline leaching of raw lithium cobalt oxide (LCO) battery scrap using a single-stage aqueous leaching solution comprising ammonia, ammonium sulfate, and ammonium chloride.

Calculated on an elemental basis, the LCO battery scrap contained 5.42 wt% copper, 28.6 wt% cobalt and 3.46 wt% lithium.

The LCO battery fragments were reacted with an aqueous leachate solution containing 45 g/L ammonia, 180 g/L ammonium sulfate, and 18 g/L ammonium chloride at 4.0 wt% solid loading.

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 in the leachate were 93.8%, 24.1% and 25.9%, respectively.

Then 100kg/t of copper was added and leaching was continued for another 2 hours. After another 2 hours of leaching, the extraction rates of copper, cobalt and lithium in the leaching solution reached 97.6%, 67.5% and 68.9% respectively.

This example shows that when copper is added, the metal extraction rate is higher.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover copper, cobalt and lithium from the leachate. Similarly, the aforementioned ammonia, ammonium sulfate and ammonium chloride can be recovered and reused using the method provided by the present invention. [Example 8]

This example discloses a three-stage leaching of a mixed feed of raw lithium nickel manganese cobalt oxide 622 (NMC622), lithium nickel manganese cobalt oxide 811 (NMC811), lithium nickel cobalt aluminum oxide (NCA) and lithium iron phosphate (LFP) battery scrap using a leaching solution comprising ammonium sulfate and ammonia. No ammonium chloride is added.

Equal weight mixtures of NMC811, NMC622, NCA and LFP battery fragments (containing 7.01% copper, 14.5% nickel, 2.48% cobalt, 2.16% manganese and 2.69% lithium) were reacted in an aqueous solution containing 220g/L ammonium sulfate and 110g/L ammonia at 9.1% solid and 50°C. After leaching for 6 hours at a pH of 9.5-9.9 and a redox potential of less than -90mV (Ag/AgCl electrode), the extraction rates of the aforementioned nickel, cobalt, copper, lithium and manganese reached 58.8%, 45.8%, 49.4%, 47.4% and 78.3%, respectively. Metals were mainly extracted from NMC622 and NMC811 batteries.

The solid residue from the first leaching was found to contain 6.17% copper, 8.55% nickel, 0.468% cobalt, 0.67% manganese and 2.10% lithium.

The solid residue was reacted in a solution containing 354 g/L ammonium sulfate at 5.1% solid 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 extraction rates of nickel, cobalt, copper, lithium and manganese reached 15.1%, 77.6%, 67.7%, 75.5% and 8.5%, respectively. Except for nickel, all other metals were extracted from all types of batteries. Nickel was mainly extracted from materials NMC811 and NMC622, and nickel was not leached from materials NMC811 and NMC622 in the initial leaching.

The extraction rates of nickel, cobalt, copper, lithium and manganese in the two leaching stages were 64.5%, 85.5%, 87.5%, 86.1% and 79.8%, respectively.

The solid residue from the second leach was initially screened at 180 microns to remove coarse material, particularly steel and aluminum foil. The screened material contained 1.61% copper, 8.2% nickel, 0.49% cobalt, 0.69% manganese and 0.59% lithium.

The solid residue from the second leach was re-slurried in water to 30% solids followed by addition of sulfuric acid to a target pH of 1.90. After leaching for 6 hours at 70°C, the extraction yields of Ni, Co, Cu, Li and Mn reached 58.9%, 98.3%, 37.1%, 64.9% and 7.0%, respectively. The acid consumption was significantly lower (<100kg/t) than the equivalent pure sulfuric acid process (>1200kg/t). It is expected that metal extraction will increase with increasing acid addition.

The extraction rates of the aforementioned nickel, cobalt, copper, lithium and manganese in all three leaching stages (including metal losses associated with screening) reached 85.7%, 92.3%, 99.7%, 95.5% and 80.0%, respectively. [Example 9]

This embodiment discloses leaching a mixture of lithium iron phosphate (LFP) and lithium nickel cobalt aluminum oxide (NCA) battery fragments using a single-stage leaching aqueous solution comprising ammonium sulfate and ammonium chloride, wherein the mass ratio of LFP:NCA in the mixture of battery fragments is 4:1.

Calculated by elements, the battery scrap contained 0.26 wt % copper, 4.39 wt % nickel, 0.50 wt % cobalt, 19.0 wt % iron and 1.99 wt % lithium.

The battery scraps were reacted with an aqueous leachate solution containing 230 g/L ammonium sulfate, 23 g/L ammonium chloride and 5.5 g/L copper (in the form of copper sulfate) at a solid loading of 4.9 wt%. Copper sulfate was added because the copper content of the battery scraps was low.

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

The extraction rates of nickel, cobalt, iron and lithium in the leaching solution were 44.0%, 75.7%, 0.43% and 94.7%, respectively.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover copper, nickel, cobalt and lithium from the leachate. Similarly, the method provided by the present invention can be used to recover ammonium sulfate and ammonium chloride for repeated use. [Example 10]

This embodiment discloses leaching a mixture of lithium iron phosphate (LFP) and lithium nickel cobalt aluminum oxide (NCA) battery fragments using a single-stage leaching aqueous solution containing ammonium sulfate, wherein the mass ratio of LFP to NCA in the mixture of battery fragments is 4:1. No ammonium chloride is added in the aforementioned leaching process.

Calculated by elements, the battery scrap contained 0.26 wt % copper, 4.39 wt % nickel, 0.50 wt % cobalt, 19.0 wt % iron and 1.99 wt % lithium.

The battery scraps were reacted with an aqueous leachate solution containing 230 g/L ammonium sulfate and 5.5 g/L copper (in the form of copper sulfate) at a solid loading of 4.9 wt%. Copper sulfate was added due to the low copper grade of the battery scraps.

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

The extraction rates of nickel, cobalt, iron and lithium in the leaching solution were 20.5%, 43.4%, 0.26% and 81.6%, respectively.

Although not disclosed in this embodiment, the method provided by the present invention can be used to selectively recover copper, nickel, cobalt, manganese and lithium from the aforementioned leaching solution. Similarly, the method provided by the present invention can be used to recover ammonium sulfate and ammonium chloride for reuse.

It should be understood that the disclosure and definition in this specification can be extended to apply to all alternative combinations of two or more single features mentioned or evident from the text or drawings. All these different combinations constitute various optional aspects of the present invention.

1: Feed stream (LFP fragments) 3: Ammonia 6: Ammonia leachate 7: Ammonium sulfate 8: Air 9: Crude slag 10, 11: Ammonium sulfate leachate 12, 16: Water 13, 15: Leaching residue 17: Acid leachate 18: Copper product 19, 22: Raffinate 20: Manganese product 21: Steam 24: Ammonium sulfate leachate 25: Condensate 27: Nickel product 29: Drainage 30: Lithium product 31, 35: Wash water 37: Cobalt product 38: Drainage 39: Ammonia/Ammonium sulfate solution 40: Leaching ammonia solution 41: Steam 43: Condensate 45: Centrifugation to ammonium sulfate leaching 48: Lithium product 49: Washing water 50: Washing liquid to ammonium sulfate leaching 100: Crushing 110: Ammonia leaching 120: Solid-liquid separation step 130: Ammonium sulfate leaching 140: Concentrator 150, 260: Filter 160: Acid leaching 170, 190: Filter 180: Manganese oxide precipitation 200: Crystallizer 210: Centrifuge 220: Roasting 230: Washer 240: Copper sulfate electrolytic precipitation 270: Ammonia recovery 280: Crystallizer 290: Centrifuge 300: Baking 310: Washer

Further description of other aspects of the invention and further implementation of the aspects described in the above paragraphs will become clear from the following description, which is given by way of example and with reference to the drawings.

FIG1 shows a process flow diagram of a method according to an embodiment of the present invention.

FIG. 2 shows a process flow chart of a method according to another embodiment of the present invention.

1: Feed flow (LFP fragments)

2: Feed flow

3: Ammonia

4: Alkaline leaching slurry

5: Concentrator underflow

6: Ammonia leaching solution

7: Ammonium sulfate

8: Air

9: Ammonium sulfate leaching discharge

10: Ammonium sulfate leaching solution

11: Concentrator underflow

12: Water

13: Leaching residues

14: Extractant

15: Extraction solution

16: Dilute sulfuric acid

17: Acid leaching solution

18: Copper products

19: Extraction residue

21: Steam

22: Leaching ammonia solution

23: Extractant

24: Ammonium sulfate leaching

25: Condensate

26: Lithium ammonium sulfate

27: Centrifuge until ammonium sulfate is leached

28: Lithium ammonium sulfate

29: Discharge fluid

30: Lithium products

31: Washing water

32: Washing liquid to the entry and exit of ammonium sulfate

100: Broken

110: Ammonia leaching

120: Concentration Machine

130: Ammonium sulfate leaching

140: Concentrated Machine

150:Filter

160: Loop

170: Filtering

180:Copper sulfate electrolytic precipitation

190: Ammonia recovery

200:Crystallizer

210: Centrifuge

220: Roasting

230: Scrubber

Claims (25)

A method for recovering metals from electronic waste or its leaching residue, characterized in that the electronic waste or the leaching residue contains copper element and one or more lithium compounds, the method comprising: Leaching the electronic waste or the leaching residue with a leaching solution containing ammonium sulfate in the presence of an oxidant to provide a leachate containing copper ions and lithium ions and a solid residue; and Separating the leachate and the solid residue. The method of claim 1, wherein the copper element is present in an amount sufficient to provide a redox potential of -100 mV or less, the redox potential being measured using an Ag/AgCl reference electrode; ideally, the redox potential is -150 mV or less. The method of claim 1 or 2, wherein the oxidant is present in an amount sufficient to provide a redox potential of +50 mV or more, the redox potential being measured using an Ag/AgCl reference electrode; ideally, the redox potential is +100 mV or more, and more ideally, the redox potential is +150 mV or more. A method as described in any one of claims 1 to 3, wherein the temperature is from about 0°C to the boiling point or below the boiling point of the leachate under leaching operating conditions; ideally, the temperature is from about 40°C to the boiling point or below the boiling point of the leachate under leaching operating conditions. The method of any one of claims 1 to 4, wherein the leaching is carried out under atmospheric pressure. A method as described in any one of claims 1 to 5, wherein the leaching is carried out for up to 24 hours; ideally, the leaching is carried out for up to 18 hours; more ideally, the leaching is carried out for up to 12 hours; most ideally, the leaching is carried out for up to 8 hours; additionally or selectively, the leaching is carried out for at least 0.5 hours; ideally, the leaching is carried out for at least 1 hour; more ideally, the leaching is carried out for at least 1.5 hours; most ideally, the leaching is carried out for at least 2 hours. A method as described in any one of claims 1 to 6, wherein the method also includes recovering copper ions from the leachate. The method as described in claim 7, wherein, after the step of recovering copper ions from the leachate, the method also includes: crystallizing ammonium lithium sulfate from the leachate, and thermally decomposing the crystallized ammonium lithium sulfate to form a gas containing ammonia and sulfur oxides and solid lithium sulfate. The method as described in any one of claims 1 to 8, wherein, before the step of crystallizing ammonium lithium sulfate, the leachate is treated so that the leachate is ammonia-poor, copper-poor, nickel-poor, cobalt-poor, manganese-poor leachate and/or a leachate that is substantially free of ammonia, aluminum, copper, iron, nickel, cobalt or manganese. A method as described in any one of claims 1 to 9, wherein the electronic waste further comprises one or more transition metals, the oxidant is an oxide of the one or more transition metals, and the leaching solution comprises ions of the one or more transition metals. The method of claim 10, wherein the one or more transition metals are selected from the group consisting of cobalt, manganese and/or nickel. A method as described in any one of claims 1 to 11, wherein the electronic waste further comprises nickel, the leaching solution also comprises ammonia, and the amount of ammonia is such that the pH of the leaching solution is about 8.5 to about 10.5, wherein the leaching solution comprises at least copper ions, lithium ions and nickel ions. The method as described in claim 12, wherein the leaching solution comprises ammonia and ammonium sulfate, and the ratio of ammonia to ammonium sulfate is about 1:2 to about 1:20. A method as described in claim 12 or 13, wherein the method also includes simultaneously recovering copper ions and nickel ions from the leachate by solvent extraction. A method as described in any one of claims 1 to 11, wherein the electronic waste also contains cobalt, and the leaching solution further contains ammonia, the amount of ammonia is such that the pH of the leaching solution is about 8.5 to about 10.5, wherein the leaching solution contains at least copper ions, lithium ions and cobalt ions. The method of claim 15, wherein the method further comprises recovering copper ions from the leachate, and after removing the copper ions, precipitating cobalt from the leachate. The method of claim 16, wherein the step of precipitating cobalt from the leachate comprises precipitating cobalt sulfide from the leachate. A method as described in any one of claims 1 to 11, wherein the electronic waste further comprises manganese, the leaching solution further comprises a leachate containing manganese ions, and the method further comprises: Treating the leachate with an oxidizing agent to form a precipitate of manganese and provide a manganese-poor leachate containing copper ions and lithium ions; and Separating the manganese precipitate from the manganese-poor leachate. The method of claim 18, wherein the oxidant is air. A method as described in any one of claims 1 to 19, wherein the electronic waste further comprises iron and aluminum, the solid slag comprises iron and aluminum, and the leachate is an iron-poor, aluminum-poor leachate, and/or a leachate that substantially does not contain iron or aluminum. The method as described in claim 1, wherein the electronic waste contains copper element and one or more compounds of cobalt, lithium and nickel, wherein the leachate further contains ammonia, and the leachate contains cobalt ions, copper ions, lithium ions and nickel ions; after the step of separating the leachate from the solid slag, the method further comprises: Subjecting the leachate to a solvent extraction step to remove copper ions and nickel ions from the leachate and form a copper-poor, nickel-poor leachate; The poor copper and poor nickel leachate is subjected to a sedimentation step to remove cobalt ions from the poor copper and poor nickel leachate and form a poor cobalt, poor copper and poor nickel leachate; and Lithium is recovered from the poor cobalt, poor copper and poor nickel leachate, wherein, before the step of recovering lithium, the leachate is subjected to an ammonia recovery step, so that during the process of recovering lithium, the poor cobalt, poor copper and poor nickel leachate is substantially free of ammonia. A method as described in claim 21, wherein the cobalt ions include Co ²⁺ ions, and before subjecting the leachate to the solvent extraction step, the method further comprises treating the leachate with an oxidizing agent to oxidize the Co ²⁺ ions into Co ³⁺ ions. The method of claim 1, wherein the electronic waste comprises copper and one or more compounds of cobalt, lithium, manganese and nickel, wherein the leaching solution further comprises ammonia, and the leaching solution comprises cobalt ions, copper ions, lithium ions, manganese ions and nickel ions; after the step of separating the leaching solution from the solid slag, the method further comprises: treating the leaching solution with an oxidizing agent to form a precipitate of manganese and provide a manganese-poor leaching solution, wherein the manganese-poor leaching solution comprises Co ³⁺ ions; and separating the manganese precipitate from the manganese-poor leachate; subjecting the manganese-poor leachate to a solvent extraction step to remove the copper ions and nickel ions from the manganese-poor leachate and form a copper-poor, manganese-poor, and nickel-poor leachate; The poor copper, poor manganese and poor nickel leachate is subjected to a sedimentation step to remove cobalt ions from the poor copper, poor manganese and poor nickel leachate to form a poor cobalt, poor copper, poor manganese and poor nickel leachate; and lithium is recovered from the poor cobalt, poor copper, poor manganese and poor nickel leachate, wherein before the step of recovering lithium, the leachate is subjected to an ammonia recovery step, so that during the process of recovering lithium, the poor cobalt, poor copper and poor nickel leachate is substantially free of ammonia. The method as described in claim 1, wherein the leaching solution further comprises ammonia, the leachate is a first leachate, 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 leachate 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 Mixing the first leachate, the second leachate, and the third leachate to form a mixed leachate. The method of claim 24, wherein the electronic waste comprises the element copper and one or more compounds of cobalt, lithium, manganese and nickel, and the method comprises recovering one or more of the cobalt, copper, lithium, manganese and nickel from the mixed leachate.