Process for separating chemical elements from a polymetallic sample

Abstract

The present application relates to a process for separating chemical elements M1, M2 and / or M3 contained in a solid sample, such as end of life batteries or black masses, wherein M1 is an alkali metal, M2 is a transition metal and M3 is aluminum.

Description

[0001] PROCESS FOR SEPARATING CHEMICAL ELEMENTS FROM A POLYMETALLIC SAMPLE

[0002] TECHNICAL FIELD

[0003] The invention relates to the separation of metallic compounds from polymetallic samples, such as end of life batteries.

[0004] TECHNICAL BACKGROUND

[0005] Energy storage has become a global issue and a major challenge. Since the 1980s, the annual world consumption of oil has become greater than the quantities of new deposits discovered. It is therefore necessary to turn to other sources of energy, such as renewable energies, and to develop technologies for the storage of these energies in order to better manage these resources. Efforts to reduce oil consumption are particularly linked to the development of electric vehicles and batteries. While Lithium-ion batteries are now commonly used in computers and mobile phones, there remains some limitations for large-scale applications like electric vehicles. In particular, such applications require high amounts of strategic metals, such as cobalt or rare earth metals, which are expensive. The development of effective and selective recycling processes is therefore crucial in this field.

[0006] Most recycling processes, such as hydrometallurgical recycling processes, involve leaching metals from the black mass, which is a type of waste comprising crushed and shredded used battery cells. It contains mixtures of valuable metals including lithium, manganese, cobalt and nickel. Such leaching is classically performed in acidic or basic conditions, and triggers dissolution of metals. Once the metals are in solution, different separation steps are implemented to recover the metals.

[0007] However, due to the harshness of the conditions implemented for leaching metals from the black mass, impurities are also dissolved and post-treatment is needed to remove them from valuable metals. For instance, copper and aluminum are present in black mass but are not among the most valuable metals.

[0008] It would thus be useful to develop pre-treatments to be implemented before the metal leaching step of black mass, that would allow separating impurities such as copper and aluminum. Such process would among other simplify the separation treatment steps of the valuable metals, as the leached solutions would comprise less impurities and thus less further separation steps would be required to isolate valuable metals. Advantageously, such process would be carried out with a solid sample, such as a black mass, which comprises high amounts of impurities, such as copper and aluminum.

[0009] SUMMARY OF THE INVENTION

[0010] In this respect, the inventors have developed a pre-treatment process of black mass that allows removing impurities such as copper and aluminum before metallic leaching of the black mass. The process of the invention may also allow separating lithium before metallic leaching.

[0011] Thus, the present invention relates to a process for separating chemical elements Ml, M2 and / or M3 contained in a solid sample, said process comprising the steps of: a) contacting said solid sample with a first aqueous solution, so as to obtain a first liquid phase enriched in Ml, and a first solid residue, b) separating said first liquid phase and said first solid residue, c) contacting the solid sample or, when steps a) and b) are performed, the first solid residue with ammonium carbonate in a solution, so as to obtain a second liquid phase enriched in M2 and a second solid residue, d) separating said second liquid phase and said second solid residue, e) contacting the second solid residue with a base in a solution, so as to obtain a third liquid phase enriched in M3 and a third solid residue, f) separating said third liquid phase and said third solid residue, g) contacting the second solid residue or, when steps e) and f) are performed, the third solid residue with an oxidizing agent in a solution, so as to obtain a fourth liquid phase enriched in Ml and a fourth solid residue, h) separating said fourth liquid phase enriched in Ml and said fourth solid residue, and / or i) recovering Ml, M2 and / or M3 respectively from the first and / or fourth liquid phases, the 2ndliquid phase, and the third liquid phase, wherein

[0012] Ml is an alkali metal, such as lithium Li, sodium Na or a mixture thereof,

[0013] M2 is a transition metal, such as copper Cu, nickel Ni, cobalt Co or a mixture thereof, and M3 is aluminum. The separating process according to the invention allows removing Ml, M2 and / or M3, especially copper, aluminum and lithium, from the black mass before the metallic leaching step. It thus affords simplifying the further separating process of valuable metals, by limiting the amount of impurities in the leached solutions. The process also allows drastically limiting the amount of leaching reactant, such as acid or base. The process according to the invention may finally allow recovering lithium before metallic leaching, thus limiting contamination of metals with lithium, and increasing the lithium concentration in the recovered lithium, limiting by the way the post-treatment and cost thereof.

[0014] In some embodiments, Ml is lithium and M2 is copper.

[0015] In some embodiments, the process of the invention comprises the steps of: c) contacting the solid sample with ammonium carbonate in a solution, so as to obtain a second liquid phase enriched in M2 and a second solid residue, d) separating said second liquid phase and said second solid residue, and i) recovering M2 from the second liquid phase.

[0016] In some embodiments, the second solid residue comprises a solid Si comprising Ml and a solid S2 comprising M3, the solid S2 having a larger mean particle size than that of the solid Si, and step d) comprises the following substeps: d') separating the solid S2 from the second liquid phase and from the solid Si; d”) recovering the solid S2, d’”) separating the solid Si from the second liquid phase ; and d””) recovering the solid Si, preferably wherein: the solid sample comprises less than 2% by weight of Ml, more than 5% by weight of M2 and more than 10% by weight of M3, relative to the total weight of the solid sample, and the amounts of M2 and M3 in the solid Si recovered at the end of step d””) are lower than the respective amounts of M2 and M3 in the solid sample.

[0017] In some embodiments, steps (a) to (i) are implemented, and the solid sample is the solid Si recovered at step d” ” ).

[0018] In some embodiments, the solid sample comprises Ml, M2 and M3 and the process of the invention comprises the steps of: a) contacting the solid sample with a first aqueous solution, so as to obtain a first liquid phase enriched in Ml, and a first solid residue, b) separating said first liquid phase and said first solid residue, c) contacting the first solid residue with ammonium carbonate in a solution, so as to obtain a second liquid phase enriched in M2 and a second solid residue, d) separating said second liquid phase and said second solid residue, e) contacting the second solid residue with a base in a solution, so as to obtain a third liquid phase enriched in M3 and a third solid residue, f) separating said third liquid phase and said third solid residue, g) contacting the third solid residue with an oxidizing agent in a solution, so as to obtain a fourth liquid phase enriched in Ml and a fourth solid residue, h) separating said fourth liquid phase enriched in Ml and said fourth solid residue, and i) recovering Ml, M2 and M3 respectively from the first and / or fourth liquid phases, the 2ndliquid phase, and the third liquid phase.

[0019] In some embodiments, the first aqueous solution comprises or consists of water, preferably demineralized water.

[0020] In some embodiments, in step c), ammonium carbonate is generated in situ in the solution, by contacting CO2 with ammonia.

[0021] In some embodiments, steps c)-d) are implemented at least twice, each further iteration of step c) being implemented with the solid residue of the previous iteration of step d).

[0022] In some embodiments said process further comprises, after step d): e’) heating the second liquid phase to a temperature Tl, so as to obtain M2 in a solid form, and f’) recovering M2 in a solid form.

[0023] In some embodiments, in step e’) said temperature Tl is comprised between 60°C and 110°C, preferably between 70°C and 100°C.

[0024] In some embodiments, said process further comprises, after step d): e”) electroplating M2 on a substrate, and f”) recovering M2 in a solid form.

[0025] In some embodiments, in step e), the base is sodium hydroxide or potassium hydroxide, preferably sodium hydroxide, and is used at a concentration comprised between 0.5 mol / L and 5 mol / L. In some embodiments, steps e) and f) are implemented at least twice, and the third liquid phase separated in each iteration of step f) is used as the solution of the next iteration of step e), so as to obtain a third liquid phase enriched in M3, preferably saturated in M3.

[0026] In some embodiments, the third liquid phase is saturated in M3, and M3 is recovered in a solid form from said third liquid phase, preferably by filtration.

[0027] In some embodiments, said process further comprises, after step f): g’) contacting CO2 with the third liquid phase, so as to obtain M3 in a solid form, and h’) recovering M3 in a solid form, preferably as a hydroxide.

[0028] In some embodiments, in step g), the oxidizing agent is a persulfate salt, such as ammonium persulfate or sodium persulfate, preferably ammonium persulfate.

[0029] In some embodiments, step g) is implemented in activation conditions selected from the group consisting of addition of sodium hydroxide, lithium hydroxide and / or ammonia, preferably sodium hydroxide, use of a high-shear mixer and use of mechanochemistry.

[0030] In some embodiments, in step i), Ml is recovered by contacting the first and / or fourth liquid phases with a carbonate salt, preferably sodium carbonate, or a phosphate salt, preferably phosphate ammonium, and separating Ml in solid form, preferably as a carbonate.

[0031] In some embodiments,

[0032] - Ml in a solid form is a carbonate, a hydroxide, a phosphate, a sulfate, or a combination thereof, of Ml,

[0033] - M2 in a solid form is a carbonate, a hydroxide, an oxide, or a combination thereof, of M2, preferably a hydroxycarbonate of M2.

[0034] -M3 in a solid form is a carbonate, a hydroxide, an oxide or a combination thereof, of M3.

[0035] In some embodiments, the solid sample is originating from a battery or a used battery.

[0036] In some embodiments, separating step b), d) and / or f) is a filtration or a centrifugation, preferably a filtration.

[0037] In some embodiments, the concentration of ammonium carbonate at step c) is comprised between 0.05 mol / L and 5 mol / L, preferably between 0.1 mol / L and 2 mol / L.

[0038] In some embodiments, the concentration of the solid sample of step a) or of step c) and / or of the solid residue of step c), step e) and / or step g) is comprised between 100 g / L and 400 g / L, preferably it is about 200 g / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a histogram showing the leaching yield and purity of each element (initially present in a Jelly Roll black mass) in a solution obtained after a leaching step using ammonium persulfate or sodium persulfate as an oxidizing agent (Example 4a.).

[0040] Figure 2 is a histogram showing the Li extraction yields obtained after different leaching steps from a black mass using ammonium persulfate as an oxidizing agent and using either NaOH, LiOH or NH4OH as a base (Example 4b.).

[0041] Figure 3 is a histogram showing the Li and Ni purities in a solution obtained after different leaching steps from a black mass using ammonium persulfate as an oxidizing agent and using either NaOH, LiOH or NH3 as a base (Example 4b.).

[0042] Figure 4 is a histogram showing the Cu, Ni and Li purities in a solution obtained after a lithium leaching step whether preceded or not by a copper leaching step (denoted step c) - Example 4d.).

[0043] Figure 5 is a histogram showing the Cu, Ni and Li extraction yields obtained after a lithium leaching step whether preceded or not by a copper leaching step (denoted step c) - Example 4d.).

[0044] DETAILED DESCRIPTION OF THE INVENTION

[0045] The separating process of the invention is implemented on a solid sample comprising at least chemical elements Ml, M2 and / or M3.

[0046] According to the process of the invention, M2 is necessarily separated and recovered from the solid sample. In some embodiments, only M2 is separated from the solid sample. In other embodiments, Ml and / or M3 are also separated from the solid sample.

[0047] Ml is an alkali metal, such as lithium or sodium, preferably lithium.

[0048] M2 is a transition metal, such as copper, cobalt or nickel, preferably copper.

[0049] M3 is aluminum.

[0050] In the present invention, embodiments disclosed for one alkali metal (such as lithium) and / or for one transition metal (such as copper) may be implemented similarly with other alkali metals (such as Na) and / or with other transition metals (such as cobalt or nickel) respectively. In other words, the invention also encompasses the processes implemented with different alkali metals and / or different transition metals.

[0051] The process according to the invention comprises at least steps c), d) and i).

[0052] In some embodiments, the process according to the invention further comprises step a). In such embodiments, the process of the invention necessarily also comprises step b). In some embodiments, the process according to the invention comprises steps a), b), c), d) and i).

[0053] In some embodiments, the process according to the invention further comprises step e). In such embodiments, the process of the invention necessarily also comprises step f). In some embodiments, the process according to the invention comprises steps c), d), e), f) and i). In some embodiments, the process according to the invention comprises steps a), b), c), d), e), f) and i).

[0054] In some embodiments, the process according to the invention further comprises step g). In such embodiments, the process of the invention necessarily also comprises step h). In some embodiments, the process according to the invention comprises steps c), d), g), h) and i). In some embodiments, the process according to the invention comprises steps a), b), c), d), g), h) and i). In some embodiments, the process of the invention comprises steps c), d), e), f), g), h) and i).

[0055] In some embodiments, the process according to the invention comprises all steps, i.e. steps a) to i). In some embodiments, steps are implemented in the a) to i) order. In other embodiments, steps may be implemented in a different order. Steps a) and b), when present, may be implemented before all other steps. Steps c) and d) are necessarily implemented before steps g) and h), when steps g) and h) are present.

[0056] In the present invention, each step is described to be implemented on the solid sample recovered at the previous step, all consecutive steps a) to i) being considered to be implemented. Of course, when not all steps are implemented, each step is performed on the solid sample recovered at the previous implemented step of the process.

[0057] In some embodiments, the process according to the invention may comprise additional preliminary or intermediate steps before and / or between steps a) to i). For instance, a preliminary step may be implemented before step a) to remove poly vinylidene fluoride (PVDF). Such preliminary step may be performed by washing, such as washing with dimethylsulfoxide DMSO solvent, or by calcination. In some embodiments, intermediate steps are implemented between two steps of the process in order to separate other elements from the sample. For instance, an intermediate step for separating at least one, preferably all, of Ni, Co and Mn may be implemented before aluminum pre-leaching steps e) and f), preferably between copper preleaching steps c) and d) and aluminum pre-leaching steps e) and f).

[0058] The solid sample on which the separating process according to the invention is carried out can be any type of solid sample comprising Ml, M2 and / or M3 as defined herein, preferably comprising Ml, M2 and M3. It can be a solid sample of any origin. For instance, the solid sample may be originating from a battery, wastes from batteries production, effluents from steel industry or dairy industry, red mud, ores, or fly ash. In a particular embodiment, the solid sample is a sample originating from a battery, for instance a nickel-metal hydride or Li-ion battery, or a component thereof (such as a battery cathode). The solid sample may be of any one of the following formulae: LaiNigCoMn, AlxFeyNizMnCoO with x and y being each independently from 0.1 and 10, and z is an integer from 1 to 8 (preferably 8), LiAlwCuFeNikMnCoO with w being from 0.1 and 10 and k is an integer from 1 to 8 (preferably 8), or LiAlo.iNio.sCoo.iMno.iO.

[0059] Steps a) and b): lithium selective pre-leaching

[0060] The first step of the process according to the invention is a selective pre-leaching step of the alkali metal, such as lithium or sodium, preferably lithium, present in the solid sample. When the solid sample is black mass, the presence of available lithium may be due among others to the classical mechanical pre-treatment of black mass. The pre-leaching step of leaching is implemented by suspending and / or dissolving the solid sample in water.

[0061] Step a) of the separating process according to the invention thus consists in contacting said solid sample with a first aqueous solution, so as to obtain a first liquid phase enriched in Ml, Ml being preferably lithium, and a first solid residue.

[0062] The concentration of the solid sample in the first aqueous solution is preferably comprised between lOOg / L and 300g / L, preferably between 150g / L and 250g / L, more preferably between 175g / L and 225g / L. In specific embodiments, the concentration of the solid sample in the first aqueous solution is about 200g / L.

[0063] In some embodiments, the aqueous solution of step a) is water. Water may be demineralized water or carbonated water, preferably demineralized water.

[0064] Contacting step a) may be implemented at any temperature and pressure, and for any duration, allowing the alkali metal, such as lithium or sodium, preferably lithium, to dissolve in water. In some embodiments, contacting step a) is implemented at ambient pressure.

[0065] In some embodiments, contacting step a) is implemented at a temperature higher than room temperature, preferably at a temperature comprised between 50°C and 100°C, more preferably at a temperature comprised between 70°C and 90°C, in particular at a temperature comprised between 75°C and 85°C. In some embodiments, contacting step a) is implemented at a temperature of about 80°C.

[0066] In some embodiments, contacting step a) is implemented for a duration comprised between 15 minutes and 10 hours, preferably comprised between 30 minutes and 4 hours, more preferably comprised between 1 hour and 3 hours. In some embodiments, contacting step a) is implemented for a duration of about 2 hours.

[0067] Step b) of separating said first liquid phase and said first solid residue may be performed by any liquid-solid separation known in the art. Step b) may be for instance carried out by filtration, centrifugation, or reverse osmosis.

[0068] More generally, each recovering and / or separating step of the process of the invention may be independently carried out by filtration, centrifugation, or reverse osmosis.

[0069] In some embodiments, step b) is implemented by filtration with a pore size comprised between 0.5 micrometer and 5 micrometers, preferably comprised between 0.5 micrometer and 2 micrometers, more preferably a pore size of about 1 micrometer.

[0070] The alkali metal, such as lithium, is recovered in the first liquid phase, preferably as a hydroxide. Further treatment may be implemented on said first liquid phase, in order to obtain the alkali metal Ml in a solid form and preferably separate Ml in a solid form from the corresponding liquid phase.

[0071] “Mn in a solid form”, n being an integer ranging from 1 to 3, refers to a solid, in particular a solid salt, comprising the chemical element Mn. Preferably, “Mn in a solid form” is a carbonate of Mn, a hydroxide of Mn, an oxide of Mn, or a combination thereof.

[0072] Steps a)-b) typically allow recovering the alkali metal, such as lithium or sodium, preferably lithium, with a yield comprised between 4 and 15% in weight relative to the total weight of alkali metal, such as lithium, in the solid sample. ■ Steps c) and d): copper selective pre-leaching

[0073] The second step of the process according to the invention is a selective pre-leaching step of the transition metal, such as copper, present in the solid sample or in the first solid residue obtained after lithium pre-leaching.

[0074] In some embodiments, copper pre-leaching steps c) and d) are implemented after lithium preleaching steps a) and b). In such embodiments, step c) is carried out with the first solid residue obtained at the end of step b).

[0075] In other embodiments, copper pre-leaching steps c) and d) are implemented without carrying out prior steps a) and b). In such embodiments, step c) is carried out with the solid sample. In such embodiments, the process of the invention may comprise steps c), d) and i) and enables to separate at least M2, such as copper, from the solid sample. In other words, in such embodiments, the process of the invention preferably does not comprise steps a), b), e), f), g) and / or h). Such embodiments are typically carried out with a solid sample which comprises an important amount of metallic impurities. For example, the solid sample may comprise less than 2% by weight of Ml, such as lithium (e.g. between 0 % and 2% by weight), more than 5% by weight of M2, such as copper (e.g. between 5% and 95 % by weight) and more than 10% by weight of M3 (e.g. between 10% and 95 % by weight). Each weight percentage is expressed relative to the total weight of the solid sample. This may be the case, for example, for a battery, such as a Li-ion battery. In such embodiment, the solid sample is a sample typically originating from a battery, a used battery, or a component thereof (such as a battery cathode). The solid sample may be a black mass.

[0076] Step c) of the separating process according to the invention consists in contacting the first solid residue obtained at step b) or the solid sample with ammonium carbonate in a solution, so as to obtain a second liquid phase enriched in M2 and a second solid residue.

[0077] The concentration of the first solid residue or the solid sample in the solution is preferably comprised between lOOg / L and 300g / L, preferably between 150g / L and 250g / L, more preferably between 175g / L and 225g / L. In specific embodiments, the concentration of the first solid residue in the first aqueous solution is about 200g / L.

[0078] Especially when step c) is carried out with the solid sample (i.e. without carrying out prior steps a) and b)), the concentration of the solid sample in the solution may depend on the required M2 concentration in the second liquid phase. It is the knowledge of one skilled in the art to determine the necessary amount of the solid sample to be contacted with the solution in order to obtain the required M2 concentration in the second liquid phase, for example in order to obtain a M2 (such as copper) concentration comprised between 35 g / L and 40g / L.

[0079] The solution is preferably an aqueous solution.

[0080] Contacting step c) may be implemented at any temperature and pressure, and for any duration, allowing the transition metal, such as copper, nickel or cobalt, preferably copper, to dissolve in the solution.

[0081] In some embodiments, contacting step c) is implemented at ambient pressure.

[0082] In some embodiments, contacting step c) is implemented at a temperature higher than room temperature, preferably at a temperature comprised between 50°C and 100°C, more preferably at a temperature comprised between 70°C and 90°C, in particular at a temperature comprised between 75°C and 85°C. In some embodiments, contacting step c) is implemented at a temperature of about 80°C. In other embodiments, especially when step c) is carried out with the solid sample, contacting step c) is implemented at ambient temperature or higher than the ambient temperature, for instance it may be implemented at a temperature comprised between 20°C and 40°C.

[0083] In some embodiments, especially when step c) is carried out with the solid sample, contacting step c) is carried out under a continuous air flow.

[0084] In some embodiments, contacting step c) is implemented for a duration comprised between 15 minutes and 10 hours, preferably comprised between 30 minutes and 4 hours, more preferably comprised between 1 hour and 3 hours. In some embodiments, contacting step c) is implemented for a duration of about 2 hours.

[0085] In some embodiments, ammonium carbonate is introduced in the solution as an ammonium carbonate salt, for example at a concentration comprised between 0.05 mol / L and 5 mol / L, preferably between 0.05 mol / L and 3 mol / L, more preferably at a concentration comprised between 0.1 mol / L and 2 mol / L.

[0086] In other embodiments, ammonium carbonate is formed in situ, for instance by contacting an ammonia solution with carbon dioxide, preferably by contacting gaseous carbon dioxide (for instance by bubbling) with an ammonia solution. The concentration of NH4OH in the ammonia solution may be comprised between 0.05 mol / L and 3 mol / L, preferably comprised between 0.1 mol / L and 2 mol / L. Alternatively, the concentration of NH4OH in the ammonia solution may be comprised between 2.5 mol / L and 10 mol / L. It is within the knowledge of one skilled in the art to determine the necessary amount of carbon dioxide, especially the necessary amount of gaseous carbon dioxide, to be contacted with the ammonia solution in order to obtain the desired amount and / or concentration of ammonium carbonate. In some embodiments, carbon dioxide, especially gaseous carbon dioxide, is contacted with the ammonia solution in an amount suitable for a solution pH of at least 8, preferably at least 8.5, for example between 8.5 and 9.5, to be obtained. In an embodiment, carbon dioxide, especially gaseous carbon dioxide, is contacted with the ammonia solution in an amount suitable for a solution pH of about 8.5 to be obtained.

[0087] Step d) of separating said second liquid phase and said second solid residue may be performed by any liquid- solid separation known in the art. Step d) may be for instance carried out by filtration, centrifugation, or reverse osmosis.

[0088] In some embodiments, step d) is implemented by filtration with a pore size comprised between 0.5 micrometer and 5 micrometers, preferably comprised between 0.5 micrometer and 2 micrometers, more preferably a pore size of about 1 micrometer.

[0089] The transition metal, such as copper, nickel or cobalt, preferably copper, is recovered in the second liquid phase, preferably as Cu(NH3)4CO3. Further treatment may be implemented on said second liquid phase, in order to obtain the transition metal M2 in a solid form and preferably separate M2 in a solid form from the corresponding liquid phase. M2 in a solid form is preferably a carbonate or a hydroxide of M2, preferably a carbonate or a hydroxide of copper.

[0090] Such further treatment may be for instance evaporation and / or stripping.

[0091] In some embodiments, the further treatment comprises contacting the second liquid phase with a gas flow, such as a nitrogen flow or a pressurized air flow, so as to evaporate NH3 and / or CO2, and to precipitate M2 in a solid form, preferably copper in a solid form. In other embodiments, the further treatment comprises placing the second liquid phase under reduced pressure, preferably under vacuum, such as at a pressure comprised between 100 mbars and 400 mbars, preferably between 200 mbars and 400 mbars, so as to evaporate NH3 and / or CO2, and to precipitate M2 in a solid form, preferably copper in a solid form. Such further evaporation treatment is preferably performed at a temperature higher than room temperature, preferably at a temperature comprised between 50°C and 100°C, more preferably at a temperature comprised between 70°C and 90°C, in particular at a temperature comprised between 75°C and 85°C. In some embodiments, the further evaporation treatment is implemented at a temperature of about 80°C. In some embodiments, steps c)-d) are implemented at least twice, each further iteration of step c) being implemented with the second solid residue separated at the previous iteration of step d). In some embodiments, steps c)-d) are implemented twice, three times or four times, preferably twice. Implementing steps c)-d) at least twice is particularly useful when the solid sample contains high amounts of transition metal M2, such as copper, cobalt or nickel, preferably copper. High amounts may refer for instance to amounts of at least 2 wt %, at least 5 wt % or at least 10 wt %.

[0092] In some embodiments, the amount of transition metal M2, such as copper, in the solid sample is of at least about 2 % in weight relative to the total weight of the solid sample. In such embodiments, steps c) and d) are typically implemented at least twice.

[0093] Steps c)-d) typically allow recovering the transition metal, such as copper, with a yield comprised between 90 and 100% in weight relative to the total weight of the transition metal M2 in the solid sample.

[0094] In other embodiments, especially when step c) is carried out with the solid sample (i.e. without carrying out prior steps a) and b)), the second solid residue obtained at the end of step c) typically comprises two solids: a solid Si comprising Ml and a solid S2 comprising M3, the solid S2 having a larger mean particle size than that of the solid Si. For instance, the solid Si has a mean particle size comprised between 1pm and 100pm; whereas the solid S2 has a mean particle size higher than 100pm, for example comprised between 100pm and 2mm. The mean particle size may be determined by any suitable technique known in the art, such as for instance by Laser diffraction analysis, Scanning Electron Microscopy, Transmission Electron Microscopy or diffraction light scattering. It is understood that a mean particle size refers to the diameter of the sphere, when the particles are perfect spherical particles, and to the equivalent diameter, when the particles are not perfect spherical particles (i.e. the diameter of a sphere that would behave the same way as the non-spherical particle). The mean size is an arithmetic mean value in number.

[0095] In these embodiments, step d) comprises the following substeps: d') separating the solid S2 from the second liquid phase and from the solid Si; d”) recovering the solid S2, d’”) separating the solid Si from the second liquid phase ; and d””) recovering the solid Si.

[0096] Substep d’) may be implemented by any known liquid-solid separation technique. For example, it can be implemented by a filtration step with a pore size allowing the second liquid phase and the solid Si to pass through, while retaining the solid S2. For instance, substep d’) may be implemented by filtration with a pore size comprised between 100 pm and 500 pm.

[0097] At the end of substep d”), the recovered solid S2 typically comprises M3 which may be advantageously valorized, for example by a dissolution in a caustic solution. For instance, the recovered solid S2 is a carbonate, a hydroxide, an oxide or a combination thereof of M3.

[0098] Substep d”’) may also be implemented by any known liquid-solid separation technique. For example, it can be implemented by a filtration step with a pore size allowing the second liquid phase to pass through, while retaining the solid Si. For instance, substep d”’) may be implemented by filtration with a pore size comprised between 0.5 pm and 5 pm, preferably comprised between 0.5 pm and 2 pm, and more preferably a pore size of about 1 pm.

[0099] At the end of substep d””), the recovered solid Si comprises Ml, such as lithium. It also typically comprises remaining traces of M2, such as copper, and traces of M3. The amounts of M2 and M3 in the recovered solid Si are typically lower than the respective amounts of M2 and M3 in the solid sample. That is to say, the recovered solid Si typically comprises less than 5% by weight of M2 and less than 10% by weight of M3, relative to the total weight of the solid Si. In such embodiments (when step d) comprises substeps d’) to d””)), steps e) and f) as described below may not be implemented, since M3 is recovered at the end of substep d”) in the solid S2.

[0100] Advantageously, the remaining traces of M2 and M3 in the recovered solid Si may be further separated and recovered, for instance by implementing steps (a) to (i) with the solid Si recovered at step d””) as the solid sample (used in step a)). In other words, the process of the invention may comprise at least 2 iterations of steps a) to i): in the first iteration, steps c), d’)- d””) and i) are implemented, and in the second iteration, steps a) to i) are implemented.

[0101] In some embodiments, the process further comprises, after step d): e’) heating the second liquid phase to a temperature Tl, so as to obtain M2 in a solid form, and f’) recovering M2 in a solid form.

[0102] In some embodiments, in step e’) said temperature Tl is comprised between 60°C and 110°C, preferably between 70°C and 100°C.

[0103] In some embodiments, ammonium carbonate is added in the second liquid phase during step e’ ) and a liquid phase is obtained and recovered at the end of step f ’ ) . The liquid phase recovered at the end of step f’) may advantageously be reused in a further step c), when steps c)-d) are implemented at least twice.

[0104] In alternative embodiments, the process further comprises, after step d): e”) electroplating M2 on a substrate, and f”) recovering M2 in a solid form.

[0105] Typically, a liquid phase is obtained and recovered at the end of step f”), which is depleted in M2, such as copper. In some embodiments, the liquid phase recovered at the end of step f”) is reused in a further step c), when steps c)-d) are implemented at least twice, with a supplement of ammonium carbonate if needed.

[0106] In one embodiment, the substrate in step e”) is a grid electrode, such as titanium, platinum or stainless steel grid electrode. For example, the substrate in step e”) is a titanium grid counterelectrode, preferably coated with a Mixed Metal Oxide (or MMO).

[0107] Electroplating step e”) may for instance be implemented in at least one, preferably all, the following conditions: o electrical potential range : from -0.5VAg / Agci to -0.7VAg / Agci; o room temperature (ie 25 °C ±5 °C); o room atmosphere ; o stirring, preferably 250 rpm stirring ; o Glassy carbon working electrode, preferably with a 7 cm2surface; o platinum counter-electrode ; o Ag / AgCl reference electrode ; and / or o deposition time comprised between 1.5 and 4 hours, preferably about 2 hours.

[0108] Alternatively, electroplating step e”) may for instance be implemented in at least one, preferably all, the following conditions: o current density: from 200 A / m2to 400 A / m2, preferably 300 A / m2; o room temperature (ie 25 °C ±5 °C); o room atmosphere; o without any stirring; o titanium electrode, preferably cylindrical and / or with a 120 cm2surface; o titanium grid counter-electrode, preferably coated with a MMO; and / or o deposition time comprised between 1.5 and 4 hours, preferably about 2 hours.

[0109] At the end of step f’) or f”), M2, such as copper, is advantageously recovered in a solid form with a high purity, and may be further valorized. ■ Steps c) and f): aluminum selective pre-leaching

[0110] The third step of the process according to the invention is a selective pre-leaching step of aluminum present in the second solid residue obtained after M2 pre-leaching.

[0111] Step e) of the separating process according to the invention consists in contacting the second solid residue with a base in a solution, so as to obtain a third liquid phase enriched in M3 and a third solid residue.

[0112] The concentration of the second solid residue in the solution is preferably comprised between lOOg / L and 400g / L, preferably between 150g / L and 300g / L, more preferably between 175g / L and 225g / L. In specific embodiments, the concentration of the second solid residue in the first aqueous solution is about 200g / L.

[0113] The solution is preferably an aqueous solution.

[0114] The base may be any suitable base known in the art, preferably a strong base, more preferably sodium hydroxide or potassium hydroxide. In a preferred embodiment, the base is sodium hydroxide.

[0115] The concentration of base in the solution is preferably comprised between 0.1 mol / L and 6 mol / L, preferably between 0.5 mol / L and 5 mol / L, preferably between 1 mol / L and 2.5 mol / L, more preferably about 1 mol / L, 1.5 mol / L, 2 mol / L or 2.5 mol / L, in particular about 1 mol / L.

[0116] Contacting step e) may be implemented at any temperature and pressure, and for any duration, allowing the aluminum to dissolve in water.

[0117] In some embodiments, contacting step e) is implemented at ambient pressure.

[0118] In some embodiments, contacting step e) is implemented at a temperature higher than room temperature, preferably at a temperature comprised between 50°C and 100°C, more preferably at a temperature comprised between 70°C and 90°C, in particular at a temperature comprised between 75°C and 85°C. In some embodiments, contacting step e) is implemented at a temperature of about 80°C.

[0119] In some embodiments, contacting step e) is implemented for a duration comprised between 15 minutes and 10 hours, preferably comprised between 30 minutes and 4 hours, more preferably comprised between 1 hour and 3 hours. In some embodiments, contacting step e) is implemented for a duration of about 2 hours. Step f) of separating said first liquid phase and said first solid residue may be performed by any liquid- solid separation known in the art. Step f) may be for instance carried out by filtration, centrifugation, or reverse osmosis.

[0120] In some embodiments, step f) is implemented by filtration with a pore size comprised between 0.5 micrometer and 5 micrometers, preferably comprised between 0.5 micrometer and 2 micrometers, more preferably a pore size of about 1 micrometer.

[0121] In some embodiments, steps e)-f) are implemented at least twice, preferably 2 to 5 times, and each further iteration of step e) is performed with the third liquid phase of the previous iteration of step f). In some embodiments, steps e)-f) are implemented 2, 3, 4 or 5 consecutive times.

[0122] Aluminum is recovered in the third liquid phase, preferably as a NaAIOi. Further treatment may be implemented on said third liquid phase, in order to obtain M3 in a solid form and preferably separate M3 in a solid form from the corresponding liquid phase.

[0123] Further treatment may be implemented for instance by saturation of the third liquid phase, especially when steps e)-f) are repeated, and further separation of M3 in a solid form from the corresponding liquid phase by any suitable method, preferably by filtration. Saturation of the liquid phase may be performed at a temperature higher than room temperature, preferably at a temperature comprised between 50°C and 100°C, more preferably at a temperature comprised between 70°C and 90°C, in particular at a temperature comprised between 75°C and 85°C. In some embodiments, saturation of the liquid phase is implemented at a temperature of about 80°C.

[0124] Alternatively, further treatment may be performed by contacting the third liquid phase with carbon dioxide, preferably gaseous carbon dioxide. The amount of carbon dioxide to be added may be determined by one skilled in the art depending among others on the desired pH to obtain. In some embodiments, carbon dioxide is added until a pH of 8 or less, preferably a pH of 7.5 or less, is obtained. In a specific embodiment, carbon dioxide is added until a pH of about 7.5 is obtained. In such embodiment, M3, preferably aluminum, preferably precipitates as a hydroxide.

[0125] Steps g) and h ): lithium selective leaching

[0126] The fourth step of the process according to the invention is a selective leaching step of the alkali metal such as lithium or sodium, preferably lithium, that is present in the third solid residue after lithium pre-leaching, copper pre-leaching and aluminum pre-leaching. Step g) of the separating process according to the invention consists in contacting the third solid residue with an oxidizing agent in a solution, so as to obtain a fourth liquid phase enriched in Ml and a fourth solid residue.

[0127] The concentration of the third solid residue in the solution is preferably comprised between lOOg / L and 400g / L, preferably between 150g / L and 250g / L, more preferably between 175g / L and 225g / L. In specific embodiments, the concentration of the first solid residue in the first aqueous solution is about 200g / L.

[0128] The solution is preferably an aqueous solution. In some embodiments, the aqueous solution comprises the first liquid phase obtained at step b). In some other embodiments, the aqueous solution comprises water.

[0129] Contacting step g) may be implemented at any temperature and pressure, and for any duration, allowing the transition metal, such as copper, to dissolve in the solution.

[0130] In some embodiments, contacting step g) is implemented at ambient pressure.

[0131] In some embodiments, contacting step g) is implemented at a temperature higher than room temperature, preferably at a temperature comprised between 50°C and 100°C, more preferably at a temperature comprised between 70°C and 90°C, in particular at a temperature comprised between 75°C and 85°C. In some embodiments, contacting step g) is implemented at a temperature of about 80°C.

[0132] In some embodiments, contacting step g) is implemented for a duration comprised between 15 minutes and 10 hours, preferably comprised between 30 minutes and 4 hours, more preferably comprised between 1 hour and 3 hours. In some embodiments, contacting step g) is implemented for a duration of about 2 hours.

[0133] In some embodiments, the oxidizing agent is a persulfate, such as ammonium persulfate or sodium persulfate. Preferably, the oxidizing agent is ammonium persulfate. Such oxidizing agent enable to leach Ml, such as lithium, with a high yield and purity. In other embodiments, the oxidizing agent is a perchlorate. In other embodiments, the oxidizing agent is ozone.

[0134] The amount of oxidizing agent may vary in a wide range, and it may be comprised between 0.5 and 1 equivalent in moles relative to the moles of lithium present in the third solid residue. In specific embodiments, the amount of oxidizing agent is about 0.5 equivalent, about 0.65 equivalent, about 0.75 equivalent or about 1 equivalent in moles relative to the moles of lithium present in the third solid residue. In some embodiments, the oxidizing agent is contacted with the third solid residue in presence of an activating agent, such as a base. The presence of a base during the leaching step makes it possible to obtain stable and satisfactory leaching yields of Ml, while reducing the necessary amount of the oxidizing agent and while increasing the final purity of the obtained solution. The base may be selected from the group consisting of sodium hydroxide, lithium hydroxide and ammonia, preferably it is sodium hydroxide. The amount of base may vary in a wide range, and it may be comprised between 0.5 and 2.5 equivalent in moles relative to the moles of lithium present in the third solid residue. In specific embodiments, the amount of base is about 0.5 equivalent, about 0.65 equivalent, about 1 equivalent, about 1.5 equivalent or about 2.5 equivalents in moles relative to the moles of lithium present in the third solid residue.

[0135] In some embodiments, step g) is implemented by mechanochemistry. Advantageously, mechanochemistry makes it possible to extract Ml, such as lithium, with a high extraction yield while reducing the amount of reagents used and of effluents produced.

[0136] Step h) of separating said fourth liquid phase and said fourth solid residue may be performed by any liquid- solid separation known in the art. Step h) may be for instance carried out by filtration, centrifugation, or reverse osmosis.

[0137] In some embodiments, step h) is implemented by filtration with a pore size comprised between 0.5 micrometer and 5 micrometers, preferably comprised between 0.5 micrometer and 2 micrometers, more preferably a pore size of about 1 micrometer.

[0138] The alkali metal, such as lithium, is recovered in the fourth liquid phase, preferably as lithium sulfate. Further treatment may be implemented on said fourth liquid phase, in order to obtain the transition metal Ml in a solid form and preferably separate Ml in a solid form from the corresponding liquid phase. Ml in a solid form is preferably a carbonate or a phosphate of Ml, preferably a carbonate or a phosphate of lithium.

[0139] Such further treatment may be for instance performed by contacting the fourth liquid phase with a carbonate, such as sodium carbonate, or a phosphate, such as ammonium phosphate.

[0140] In some embodiments, the further treatment is performed by contacting the fourth liquid phase with a carbonate, such as sodium carbonate, optionally in presence of a base, such as sodium hydroxide. The amount of base to be added may be determined by the desired pH to obtain. In some embodiments, the pH to obtain is about 9, about 10, about 11 or about 12. Addition of the base may trigger precipitating other metals present in said fourth solution, such as nickel. In some embodiments, the carbonate, such as sodium carbonate, is added in an amount comprised between 1 and 2 equivalents in moles relative to the moles of Ml, such as lithium, present in the fourth solid residue. In specific embodiments, the amount of carbonate, such as sodium carbonate, is about 1 equivalent, about 1.5 equivalent, or about 2 equivalents.

[0141] In some embodiments, the further treatment is performed by contacting the fourth liquid phase with a phosphate, such as ammonium phosphate, optionally in presence of a base, such as sodium hydroxide. The amount of base to be added may be determined by the desired pH to obtain. In some embodiments, the pH to obtain is about 9, about 10 or about 11. Addition of the base may trigger precipitating other metals present in said fourth solution, such as nickel.

[0142] In some embodiments, the phosphate, such as ammonium phosphate, is added in an amount comprised between 1 and 3 equivalents in moles relative to the moles of Ml, such as lithium, present in the fourth solid residue. In specific embodiments, the amount of carbonate, such as sodium carbonate, is about 1 equivalent, about 2 equivalents, or about 3 equivalents.

[0143] Step i ): recovery of Ml, M2 and M3

[0144] The last step of the process according to the invention is the recovery of Ml, M2 and M3. The processes to be implemented for recovering Ml, M2 and M3 are detailed as “further treatments” for each separating steps b), d), f) and h).

[0145] Advantageously, Ml, M2 and / or M3 are recovered in a valuable form.

[0146] Advantageously, all the steps of the process of the invention described above may be implemented on an industrial scale.

[0147] In the present application, the term "about" (or ca.) preceding a value is well-known to the skilled artisan and means that said value may vary to a certain extent depending on the context in which the term is used. If certain uses of this term are not clear to the skilled artisan depending on the context, then "about" means ± 20%, preferably ± 10% of said value.

[0148] Unless otherwise indicated, when a range is expressed by means of the expression "comprised between", the limit values are included within the range described.

[0149] The invention will also be described in further detail in the following examples, which are not intended to limit the scope of this invention, as defined by the attached claims. EXAMPLES

[0150] Example 1. Process according to the invention

[0151] Example la. Lithium selective pre-leaching

[0152] 60 g of black mass were suspended in 300 mL demineralized water in a stirred round-bottom flask. The obtained suspension was heated to 80°C for 2 hours, and filtered with a 1 micrometer tissue filter.

[0153] Example lb. Copper selective pre-leaching

[0154] The solid residue (filtration retentate) obtained at example la. was suspended in 300 mL demineralized water in a stirred round-bottom flask. 4.12 g ammonium carbonate (0.14 mol / L) were added. The obtained suspension was heated to 80°C for 2 hours, and filtered with a 1 micrometer tissue filter.

[0155] Alternatively, the reaction was performed by suspending the solid residue (filtration retentate) obtained at example la. in 300 mL of an aqueous solution of 0.1 mol / L to 2 mol / L NH4OH. Carbon dioxide was bubbled in the obtained solution until pH 8.5 was reached. The obtained suspension was filtered with a 1 micrometer tissue filter.

[0156] The obtained solution (filtration permeate) was evaporated until precipitation of copper in a solid form. Table 1 below presents the purity of copper in the recovered solids with different evaporation conditions.

[0157] Example 1c. Aluminum selective pre-leaching

[0158] The solid residue (filtration retentate) obtained at example lb. was suspended in a solution of 30g sodium hydroxide in 300 mL demineralized water (2.5 mol / L) in a stirred round-bottom flask. The obtained suspension was heated to 80°C for 2 hours, and filtered with a 1 micrometer tissue filter.

[0159] The reaction was also successfully implemented by amending the following features: i. Replacing sodium hydroxide with potassium hydroxide, ii. Replacing 2.5 mol / L sodium hydroxide concentration with 1 mol / L, 1.5 mol / L or 2 mol / L, iii. Replacing 200 g / L black mass concentration with lOOg / L or 400g / L, iv. Replacing 80°C heating with room temperature stirring.

[0160] Carbon dioxide was bubbled in the obtained solution (filtration permeate) until obtaining the desired pH (7.5). The obtained suspension was filtered with a 1 micrometer tissue filter.

[0161] Table 2 below presents the purity of aluminum in the recovered solids with different reaction conditions.

[0162] Table 2

[0163] Example Id. Lithium selective leaching

[0164] The solid residue (first filtration retentate) obtained at example 1c. was suspended in 300 mL of the solution (filtration permeate) obtained at example la. in a stirred round-bottom flask. 6.56 g of sodium hydroxide (0.55 mol / L, 0.5 equivalent / black mass Li) and 37.45 g ammonium persulfate (0.55 mol / L, 0.5 equivalent / black mass Li) were added. The obtained suspension was heated to 80°C for 2 hours, and filtered with a 1 micrometer tissue filter.

[0165] The reaction was also successfully implemented by amending the following features: i. Replacing sodium hydroxide with ammonia or lithium hydroxide, ii. Replacing sodium hydroxide concentration with 0.5 equivalent / Li, 0.65 equivalent / Li, 0.75 equivalent / Li or 1 equivalent / Li, iii. Replacing ammonium persulfate concentration with 0.5 equivalent / Li, 0.65 equivalent / Li, 1 equivalent / Li, 1.5 equivalent / Li or 2.5 equivalent / Li, iv. Replacing 200 g / L black mass concentration with 100 g / L or 400 g / L, v. Replacing 80°C heating with 50°C heating.

[0166] The obtained solution (filtration permeate) was contacted with sodium carbonate (1, 1.5 or 2 equivalent / Li), and the pH was optionally adjusted to 9, 10, 11 or 12 by addition of a base such as sodium hydroxide. Lithium was recovered as lithium carbonate by filtration. Alternatively, the obtained solution (filtration permeate) was contacted with ammonium phosphate (1, 2 or 3 equivalent / Li), and the pH was optionally adjusted to 9, 10 or 11 by addition of a base such as ammonia. Lithium was recovered as lithium carbonate by filtration.

[0167] Table 3 below presents the purity of lithium in the recovered solids with different reaction conditions.

[0168] Table 3

[0169] Example 2. Optimization of the copper pre-leaching step conditions

[0170] Example 2a. Impact of a lithium pre-leaching step on copper pre-leaching step

[0171] A copper pre-leaching step was performed by suspending 10 g of a black mass in 50 mL of a (NH4)2CO3solution at 2 mol / L (15.7 g in 50 mL). The suspension was stirred and heated to 80 °C for 2 hours, and then filtered.

[0172] The same copper pre-leaching step was carried out, but after the black mass was subjected to steps a) and b) of the process of the invention (i.e. the black mass was first contacted with water so as to pre-leach lithium).

[0173] The pre-leaching yields of Cu, Ni and Li - initially present in the black mass - were determined for both experiments : 100 % of Cu were pre-leached for both experiments; 0% of Ni and 0.3% of Li were pre-leached when step a) was performed before the copper pre-leaching step whereas 0.5% of Ni and 7% of Li were pre-leached when step a) was not carried out before the copper pre-leaching step.

[0174] This example demonstrates that the implementation of step a) of the process of the invention before the copper pre-leaching step c) enables to prevent Li from being leached during the copper-pre-leaching step, and thus to improve the purity of the pre-leached copper. Example 2b. High concentration of ammonium carbonate

[0175] A black mass was suspended in demineralized water (200 g / L). The obtained suspension was heated to 80°C for 2 hours, and filtered.

[0176] 10 g of the solid residue (filtration retentate) thus obtained were suspended in 50 mL of a (NH4)2CO3solution at 2 mol / L (15.7 g in 50 mL). The suspension was stirred and heated to

[0177] 80 °C for 2 hours, and then filtered.

[0178] Table 4 below presents the pre-leaching yield of each element initially present in the black mass. Then, the obtained pre-leaching solution was heated to 80 °C and at pressure of 100 mbar for 4 hours, until the obtention of complete precipitation of copper and of a colorless solution.

[0179] Tables 5 and 6 below present respectively the yield of each element in the obtained colorless solution and the purity of each element in the obtained precipitate (or solid residue).

[0180] Table 5

[0181] This example demonstrates that even at high (NEU CCh concentration, an almost total precipitation of copper is observed.

[0182] Example 3. Process according to another embodiment of the invention

[0183] In this example, an initial solid sample originating form battery recycling comprising important amount of Cu and Al was provided. The composition of this initial solid sample was as follow:

[0184] Table 7 The following steps were performed:

[0185] 1) Copper pre-leaching:

[0186] 65.1 g of the initial solid sample were mixed with 400 mL of water (162 g / L) and 4 equivalents of NH3 were added as (NEU CCh. The mixture was stirred by bubbling air at ambient temperature for 2 hours. The objective was to leach 100 % of the copper initially present in the solid sample and obtain a first pre-leaching solution comprising about 35 g / L of copper.

[0187] A first solid residue was obtained and recovered by a filtration step and it was then re-leached with a (NEUjiCCh solution so as to analyze the residual copper content which was not leached and / or not washed.

[0188] 2) Electroplating of Cu from the first pre-leaching solution obtained at step 1):

[0189] The first pre-leaching solution was subjected to an electrochemical treatment: the first preleaching solution was placed into a 300 mL reactor which comprises a Ti cylindrical electrode of 120 cm2and a MMO-coated titanium grid counter-electrode. The whole was connected to a SX generator. At ambient temperature and without any stirring, a current density of 300 A / m2(i.e. a current of 2.8 A for about 2 hours) was applied. A kinetic monitoring of the copper concentration in the solution was performed each hour. When the copper concentration into the solution reached about 10 g / L the electrochemical treatment was stopped and the solution obtained was recovered, as well as the copper electroplated on the MMO-coated titanium grid counter-electrode.

[0190] 3) Reuse of the solution obtained at step 2) in a further copper pre-leaching step:

[0191] An appropriate amount of the initial solid sample was introduced in the solution obtained at step 2), comprising about 10 g / L of Cu, so as to obtain a second pre-leaching solution comprising 35 g / L of copper. The mixture was stirred by bubbling air at ambient temperature for 2 hours.

[0192] A second solid residue was obtained and recovered by a filtration step and it was then re-leached with a (NEUjiCCh solution so as to analyze the residual copper content which was not leached and / or not washed.

[0193] 4) Electroplating of Cu from the second pre-leaching solution obtained at step 3):

[0194] The second pre-leaching solution was subjected to the same electrochemical treatment as explain in step 2) above. In this example, copper was selectively electroplated and the solution obtained after the electrochemical treatment was reused in a further copper pre-leaching step (step c) of the process of the invention).

[0195] Example 4. Optimization Lithium leaching step conditions

[0196] Example 4a. Leaching of lithium with different oxidizing agents

[0197] A Jelly Roll (JR) black mass was provided with the following composition:

[0198] Table 8

[0199] The JR black mass was contacted with ammonium or sodium persulfate as oxidizing agent (0.65 eq. of ammonium or sodium persulfate in moles relative to moles of Li present in the JR black mass; 85 g / L of the JR black mass). The contacting step were performed at 80°C for 6 hours.

[0200] Figure 1 represents the leaching yield obtained after each leaching (either with ammonium or sodium persulfate) for each element initially present in the JR black mass. It also represents the purity of each element in both leaching solutions.

[0201] Figure 1 shows that both ammonium persulfate and sodium persulfate allow Ei to be leached with high yield and purity.

[0202] Example 4b. Eeaching of lithium with ammonium persulfate and a base

[0203] The same JR black mass as in Example 4a. was used in this example.

[0204] The JR black mass was contacted with ammonium persulfate as described above and a base (NaOH, LiOH or NH4OH - 0.5 eq. in moles of the base relative to moles of Li present in the JR black mass) was further added during the leaching step.

[0205] Figures 2 and 3 show respectively the Li extraction yields and Li purity obtained after each leaching (either with NaOH, LiOH or NH4OH). They show that the addition of a base makes it possible to obtain stable and satisfactory Li extraction yields, while reducing the necessary amount of oxidizing agent and while increasing the selectivity for Li and thus increasing the final purity of the obtained leaching solution.

[0206] Example 4c. Leaching of lithium with ammonium persulfate and by mechanochemistry

[0207] Lithium leaching steps were performed on two different JR black masses: - JR1 black mass contained 0 wt% copper and 0 wt% aluminum,

[0208] - JR2 black mass contained 2 wt% copper and 3.2 wt% aluminum.

[0209] The Li leaching steps were carried out by mechanochemistry with the following conditions:

[0210] - 6 cycles of 10 minutes;

[0211] - 1 g of JR black mass;

[0212] - 30 g of ZrO beads,

[0213] - 0.5 equivalent in moles of ammonium persulfate relative to the moles of Li present in each JR black mass;

[0214] - Solid / liquid ratio of 1.

[0215] As a comparative example, these two JR black masses were also subjected to Li leaching step in a round-bottom flask (i.e. not by mechanochemistry), using 0.5 equivalent in moles of ammonium persulfate and 0.5 equivalent in moles of NaOH relative to the moles of Li present in each JR black mass.

[0216] The results in terms of Li extraction yields for each leaching step are shown in Table 9 below:

[0217] Table 9

[0218] This example demonstrates that mechanochemistry makes it possible to extract Li with a high extraction yield while reducing the amount of reagents used and of effluents produced.

[0219] Example 4d. Impact of the copper pre-leaching step on lithium leaching step

[0220] First, a lithium pre-leaching step was performed: a black mass was suspended in demineralized water (200 g / L) and the obtained suspension was heated to 80°C for 2 hours, and then filtered.

[0221] The obtained solid residue was then subjected to a lithium leaching step with a persulfate salt as oxidizing agent and with NaOH as a base as described above.

[0222] As comparative example, the same lithium leaching step was carried out, but after the obtained solid residue was subjected to a copper pre-leaching step: the solid sample was suspended in a (NH4)2CO3solution (0.25 mol / L: 200 g / L) and the suspension was then heated at 80°C for 2 hours.

[0223] Figures 4 and 5 show respectively the Li, Cu and Ni purities and extraction yields obtained after the lithium leaching step, whether preceded or not by the copper pre-leaching step. This example demonstrates that the implementation of step c) of the process of the invention before the lithium leaching step enables to obtain a better Li purity and extraction yield.

[0224] Example 5. Yields of metal recovery from different black masses

[0225] Table 10 below presents the yield of metal recovery for different black masses with a process as described in example 1. Table 10

[0226] Scrap cathode black mass contains 0.3 wt% aluminum and 0 wt% copper.

[0227] JR1 black mass contains 0 wt% copper and 0 wt% aluminum.

[0228] JR2 black mass contains 2 wt% copper and 3.2 wt% aluminum.

[0229] JR3 black mass contains 0.5 wt% copper and 0.3 wt% aluminum.

Claims

CLAIMS1. A process for separating chemical elements Ml, M2 and / or M3 contained in a solid sample, said process comprising the steps of: a) contacting said solid sample with a first aqueous solution, so as to obtain a first liquid phase enriched in Ml, and a first solid residue, b) separating said first liquid phase and said first solid residue, c) contacting the solid sample or, when steps a) and b) are performed, the first solid residue, with ammonium carbonate in a solution, so as to obtain a second liquid phase enriched in M2 and a second solid residue, d) separating said second liquid phase and said second solid residue, e) contacting the second solid residue with a base in a solution, so as to obtain a third liquid phase enriched in M3 and a third solid residue, f) separating said third liquid phase and said third solid residue, g) contacting the second solid residue or, when steps e) and f) are performed, the third solid residue with an oxidizing agent in a solution, so as to obtain a fourth liquid phase enriched in Ml and a fourth solid residue, h) separating said fourth liquid phase enriched in Ml and said fourth solid residue, and / or i) recovering Ml, M2 and / or M3 respectively from the first and / or fourth liquid phases, the 2ndliquid phase, and the third liquid phase, whereinMl is an alkali metal, such as sodium, lithium or a mixture thereof, preferably lithium;M2 is a transition metal, such as copper, cobalt, nickel or a mixture thereof, preferably copper, andM3 is aluminum.

2. The process according to claim 1, which comprises the steps of: c) contacting the solid sample with ammonium carbonate in a solution, so as to obtain a second liquid phase enriched in M2 and a second solid residue, d) separating said second liquid phase and said second solid residue, and i) recovering M2 from the second liquid phase.

3. The process according to claim 2, wherein the second solid residue comprises a solid Si comprising Ml and a solid S2 comprising M3, the solid S2 having a larger mean particle size than that of the solid Si, and wherein step d) comprises the following substeps: d') separating the solid S2 from the second liquid phase and from the solid Si; d”) recovering the solid S2, d’”) separating the solid Si from the second liquid phase ; and d””) recovering the solid Si, preferably wherein: the solid sample comprises less than 2% by weight of Ml, more than 5% by weight of M2 and more than 10% by weight of M3, relative to the total weight of the solid sample, and the amounts of M2 and M3 in the solid Si recovered at the end of step d””) are lower than the respective amounts of M2 and M3 in the solid sample.

4. The process according to claim 1, wherein steps (a) to (i) are implemented, and wherein the solid sample is the solid Si recovered at step d””) of a process according to claim 3.

5. The process according to claim 1, wherein the solid sample comprises Ml, M2 and M3, and which comprises the steps of: a) contacting said solid sample with a first aqueous solution, so as to obtain a first liquid phase enriched in Ml, and a first solid residue, b) separating said first liquid phase and said first solid residue, c) contacting the first solid residue with ammonium carbonate in a solution, so as to obtain a second liquid phase enriched in M2 and a second solid residue, d) separating said second liquid phase and said second solid residue, e) contacting the second solid residue with a base in a solution, so as to obtain a third liquid phase enriched in M3 and a third solid residue, f) separating said third liquid phase and said third solid residue, g) contacting the third solid residue with an oxidizing agent in a solution, so as to obtain a fourth liquid phase enriched in Ml and a fourth solid residue, h) separating said fourth liquid phase enriched in Ml and said fourth solid residue, and i) recovering Ml, M2 and M3 respectively from the first and / or fourth liquid phases, the 2ndliquid phase, and the third liquid phase.

6. The process according to claim 5, wherein steps c)-d) are implemented at least twice, each further iteration of step c) being implemented with the solid residue of the previous iteration of step d).

7. The process according to any one of claims 1 to 6, wherein, in step c), ammonium carbonate is generated in situ in the solution, by contacting CO2 with ammonia.

8. The process according to any one of claims 1 to 7, wherein said process further comprises, after step d): e’) heating the second liquid phase to a temperature Tl, so as to obtain M2 in a solid form, and f’) recovering M2 in a solid form, wherein in step e’) temperature Tl is preferably comprised between 60°C and 110°C, more preferably between 70°C and 100°C.

9. The process according to any one of claims 1 to 7, wherein said process further comprises, after step d): e”) electroplating M2 on a substrate, and f”) recovering M2 in a solid form.

10. The process according to any one of claims 1 to 9, wherein in step e), the base is sodium hydroxide or potassium hydroxide, preferably sodium hydroxide, and is used at a concentration comprised between 0.5 mol / L and 5 mol / L.

11. The process according to any one of claims 1 to 10, wherein steps e) and f) are implemented at least twice, and the third liquid phase separated in each iteration of step f) is used as the solution of the next iteration of step e), so as to obtain a third liquid phase enriched in M3, preferably saturated in M3.

12. The process according to any one of claims 1 to 11, wherein said process further comprises, after step f): g’) contacting CO2 with the third liquid phase, so as to obtain M3 in a solid form, and h’) recovering M3 in a solid form, preferably as a hydroxide.

13. The process according to any one of claims 1 to 12, wherein, in step g), the oxidizing agent is a persulfate salt, such as ammonium persulfate or sodium persulfate, preferably ammonium persulfate.

14. The process according to any one of claims 1 to 13, wherein step g) is implemented in activation conditions selected from the group consisting of addition of sodium hydroxide, lithium hydroxide and / or ammonia, use of a high-shear mixer and use of mechanochemistry.

15. The process according to any one of claims 1 to 14, wherein, in step i), Ml is recovered by contacting the first and / or fourth liquid phases with a carbonate salt, preferably sodium carbonate, or a phosphate salt, preferably phosphate ammonium, and separating Ml in solid form, preferably as a carbonate.

16. The process according to any one of claims 1 to 15, wherein:- Ml in a solid form is a carbonate, a hydroxide, a phosphate, a sulfate, or a combination thereof, of Ml,- M2 in a solid form is a carbonate, a hydroxide, an oxide, or a combination thereof, of M2, preferably a hydroxycarbonate of M2.-M3 in a solid form is a carbonate, a hydroxide, an oxide or a combination thereof, of M3.

17. The process according to any one of claims 1 to 16, wherein the solid sample is originating from a battery or a used battery.

18. The process according to any one of claims 1 to 17, wherein the concentration of ammonium carbonate at step c) is comprised between 0.05 mol / L and 5 mol / L, preferably between 0.1 mol / L and 2 mol / L.

19. The process according to any one of claims 1 to 18, wherein the concentration of the solid sample of step a) or of step c) and / or of the solid residue of step c), step e) and / or step g) is comprised between 100 g / L and 400 g / L, preferably it is about 200 g / L.

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