Process for the recovery of li, ni and co from black mass obtained from end-of-life batteries

Abstract

The present invention relates to a process for recovering Li, Ni and Co with high purity and under mild conditions from black mass obtained from end-of-life batteries. The process is versatile as it allows working with different types of black mass depending on the targeted Li, Ni and Co products. The process combines steps of washing / flotation, leaching, pH control, and (selective) liquid-liquid extraction.

Description

[0001] PROCESS FOR THE RECOVERY OF LI, NI AND CO FROM BLACK MASS OBTAINED FROM END-OF-LIFE BATTERIES

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of recovery of Li, Ni and Co species, particularly to the recovery of said metals from black mass obtained from end-of-use electric vehicle batteries.

[0004] BACKGROUND

[0005] The demand for lithium-ion batteries (LIBs) is steadily increasing. Besides portable electronic devices (e.g., smartphones, tablets, video cameras), E-vehicles are the main application fields of lithium-ion batteries. Currently, the vast majority of E-vehicles have batteries the active material of which is from the NMC (LiNixMnyCozCE) or LFP (LiFePO4) family.

[0006] Compared to other battery systems, LIBs have several advantages such as high working voltage, large energy density, no memory effect, low self-discharge rate, and long cycle life. The rapid growth in the use of LIBs requires a significant amount of valuable metals such as cobalt, copper, lithium, manganese, and nickel. Elements Li, Ni and Co have been categorized as Critical Raw Materials according to the 2023 report of the European Commission (Study on the Critical Raw Materials for the EU 2023, Final Report, DOI: 10.2873 / 725585).

[0007] These elements, among many other characteristics, possess chemical properties that make them essential elements for the formulation of cathode active material (CAM) that is used in the manufacture of LIBs. LIB typically comprises positive and negative electrodes, the electrolyte, a separator, and a casing. The black mass obtained from LIBs of electric vehicle batteries is a mixture of plastic components, metals such aluminum, copper, iron, electrode materials and organic compounds. The elements of interest for CAM fabrication (Li, Ni and Co) are found together with graphite in the material of the battery electrodes. Electrode materials are classified according to the active material of the cathode, which usually includes Li, Ni, Co and Mn in different formulations: LCO: LiCoCE, LMO: Li2MnO4, NMC: LiNixMnyCozCh, NCA: LiNixCoyAlzCh, LFP: LiFePCU.

[0008] The reserves of Li, Co and Ni are limited and unevenly distributed geographically. Furthermore, the fast-changing technologies and shorter lifetime of electronic devices increase the disposal number of spent LIBs, thus, it is expected, that the mandatory recycling of LIBs will be further increased to contribute to a circular economy and minimize waste materials.

[0009] Hydrometallurgical and pyrometallurgical approaches, such as Accurec and Umicore (pyrometallurgical) or Recupyl and GEM (hydrometallurgical), respectively, are in use for metal recovery from LIBs. They employ acidic aqueous solutions and / or high processing temperatures. Pyrometallurgical approaches recover cobalt, nickel, and copper in the form of a metal alloy, however the recycling efficiency is lower than in hydrometallurgical processes due to the downcycling of manganese, aluminium, and lithium. Hydrometallurgical approaches are instead known for their ability to be highly selective towards different metals, but can involve complex multi-step recovery routes.

[0010] Alternatively, the COOL-Process (CCL-leaching), which involves as core step a leaching with supercritical CO2 (scCCL) and was initially developed for the production of Li2COs from lithium containing ores, like zinnwaldite and spodumene, has been recently adapted to recover battery-grade Li from black mass (Sandra Pavon et al., Metals 2021, 11(2), 259). Therefore, a COOL-process may represent a preliminary treatment for Li recovery which may be followed by further steps for the recovery of other valuable metals (Doreen Kaiser et al., Chemie Ingenieur Technik, 2021 vol. 93 (11), 1833-1839), however it requires high pressure equipment.

[0011] EP4082973 Al and WO2023 / 024599 Al describe methods for recovering a positive electrode active material precursor particularly in lithium batteries.

[0012] US 2022 / 127697 Al focuses on the recovery of at least valuable cobalt and nicke, from an acidic solution obtained by subjecting waste containing positive electrode materials for lithium ion secondary batteries to a wet process, the acidic solution comprising cobalt ions, nickel ions and other impurities.

[0013] US 2021 / 384563 Al discloses methods for recycling anode materials from a recycling stream derived from exhausted Li ion batteries. Such method includes receiving a precipitate almost exclusively composed of graphite.

[0014] Thus, there is a need in the art for alternative processes that maximize the separation efficiencies of valuable metals, such as Li, Ni and Co under mild conditions.

[0015] BRIEF DESCRIPTION OF THE INVENTION

[0016] The inventors have developed a process that allows the efficient recovery of Li, Ni and Co from black mass (abbreviated as BM) under consistently mild conditions. The process is versatile as it allows working with different types of black mass depending on the targeted Li, Ni and Co products. The process combines steps of washing / flotation, leaching, pH control, and (selective) liquid-liquid extraction, however the sequence of operations in the present invention allows to obtain Li, Ni and Co with high purity and under mild conditions since no high pressures nor temperatures or a combination thereof are required. Furthermore, the salts generated in the process facilitate the synthesis process of cathode active materials being already in liquid form and may also lead to improved discharge capacity.

[0017] Thus, according to an aspect, the invention refers to a process for recovering Li, Ni and Co from black mass comprising said elements, said process comprising the steps of: a) contacting black mass with an aqueous solution to obtain an aqueous solution (A) comprising at least 30 wt.% of the starting Li present in the black mass and a solid residue (A’); b) leaching the solid (A’) with an aqueous solution of an inorganic acid having a pH between 0 and 3, to obtain a leached aqueous solution (B), comprising Li, Ni and Co, and a non-leached solid residue (B’) comprising the remaining Ni and Co; c) adjusting the pH of the aqueous solution (B) in the range 3.5 - 6.5, to obtain an aqueous solution (C) comprising Li, Ni and Co and a solid residue (C’); d) extracting Co from the aqueous solution (C) with at least one Co-selective organic extractant, to obtain an organic phase (D) comprising Co and an aqueous phase (D’) comprising Li and Ni, said Li and Ni being optionally further separated by selective precipitation and / or extraction; e) leaching the solid residue (B’) obtained in step b) by contacting it with a mixture comprising an aqueous solution of an inorganic acid and an oxidizing agent at a temperature between 25 and 60°C, to obtain an aqueous solution (E) and a solid residue (E’), wherein the aqueous solution (E) comprises Ni and Co and wherein the solid residue (E’) may comprise Co; f) adjusting the pH of the aqueous solution (E) in the range 4.5 - 6.5 to obtain an aqueous solution (F) and a solid residue (F’); and g) extracting the aqueous solution (F) with at least one Ni-and Co-selective organic solvent to obtain an organic phase (G) comprising Ni and Co, and an aqueous phase (G’); and, optionally: h) when the solid residue (E’) comprises Co, leaching said solid residue (E’) with at least an aqueous solution of an inorganic acid to obtain an aqueous solution (H) comprising Co and a solid residue (H’); i) adjusting the pH of the aqueous solution (H) in the range 2.5 - 6.0 to obtain an aqueous solution (I) and a solid residue (F); and j) extracting the aqueous solution (I) with at least one Co-selective organic solvent to obtain an organic phase (J) comprising Co and an aqueous phase (J’).

[0018] Another aspect of the invention refers to the use of the recovered Li, Ni and Co in making a cathode active material (CAM).

[0019] BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 shows a flow-chart diagram of an embodiment of the process of the invention as also detailed in Example 1.

[0021] Figure 2 shows a flow-chart diagram of another embodiment of the process of the invention. It corresponds to the same process as in Example 1 but including the optional steps h) to j). Figure 3 shows a flow-chart diagram of another embodiment of the process of the invention. It corresponds to the process of Example 2, which is the same process as in Example 1 but conducting washing step a) with flotation agents.

[0022] Figure 4 shows a flow-chart diagram of another embodiment of the process of the invention. It corresponds to the same process as in Example 1 but including the optional steps h) to j) and conducting the washing step with flotation agents.

[0023] DETAILED DESCRIPTION OF THE INVENTION

[0024] All terms as used herein in this application, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. Other more specific definitions for certain terms as used in the present application are as set forth below and are intended to apply uniformly throughout the specification and claims unless an otherwise expressly set out definition provides a broader definition.

[0025] Throughout the description and claims the word “comprises" and variations of the word, are not intended to exclude other technical features, additives, components or steps. Furthermore, the word “comprise” encompasses the cases of “consist of’ and “consists essentially of’. Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention.

[0026] For the purposes of the invention, any ranges given include both the lower and the upper end-points of the range. Ranges or values given, such as temperatures, times, ratios, pH values and the like, should be considered approximate when they are defined by the term “about” (i.e. with a 5% margin of variation around indicated point). Various embodiments of the invention will be discussed below.

[0027] In the context of the invention, the term “diameter”, when referring to the diameter of a particle, refers to an average diameter of a particle whereby 80% of the population of particles have a diameter below a certain value or within a specific range. Such term is also commonly referred to in the art as “D80”.

[0028] The different yields mentioned throughout the specification, including the examples, are calculated as follows:

[0029] For leaching steps, the yield (expressed as a percentage) of leaching of metal species is calculated as (i) the ratio of the weight amount of metals in the liquid fraction resulting from the lixiviation step to the weight amount of metals in the black mass or as (ii) the ratio of the difference between the weight amount of metals in the black mass and the weight amount of metals in the leaching residue.

[0030] As will be appreciated by the skilled person, both approaches for the determination of the leaching yield provide identical results. For precipitation steps, the precipitation yield (expressed as a percentage) is calculated as (i) the ratio of the weight amount of a metal in the precipitated solid fraction to the weight amount of the same metal in the inlet liquid fraction or as (ii) the ratio of the difference between the weight amount of metal in the inlet liquid fraction and the weight amount of said metal in the precipitation liquor, to the weight amount of said metal in the inlet liquid fraction.

[0031] As will be appreciated by the skilled person, both approaches for the determination of the precipitation yield provide identical results.

[0032] For extraction steps, the extraction yield (expressed as a percentage) of metal species is calculated as (i) the relationship between the weight of the metal of interest in the inlet charged aqueous liquor minus the weight of this metal in the discharged aqueous liquor and the weight of the metal of interest in the inlet charged aqueous liquor or as (ii) the ratio between the weight of the metal of interest in the charged organic phase and the weight of the metal of interest in the inlet charged aqueous liquor.

[0033] As will be appreciated by the skilled person, both approaches for the determination of the extraction yield provide identical results.

[0034] For stripping steps, the stripping yield (expressed as a percentage) of the metal species is calculated as (i) the ratio between the weight of the metal of interest in the inlet charged organic phase minus the weight of the metal in the discharged organic phase and the weight of the metal of interest in the inlet charged organic phase or as (ii) the ratio of the weight of the metal of interest in the charged aqueous phase and the weight of this metal of interest in the inlet charged organic phase.

[0035] As will be appreciated by the skilled person, both approaches for the determination of the stripping yield provide identical results.

[0036] Step a)

[0037] In step a), black mass comprising Li, Ni and Co is contacted with an aqueous solution.

[0038] The term “black mass” (BM) as used throughout the application refers to a product originating from Li-ion batteries or their waste, such as new or waste Li-ion batteries, spent or end-of-life batteries, production or battery scrap, electrode materials or other pre- processed battery materials.

[0039] The Li-ion batteries are usually dismantled; metals such as Al, Fe, and Cu from casing and cabling are separated, then battery materials are shredded, optionally pre-processed, for example by grinding and / or heat treatment (the latter removes most of electrolyte or graphite materials), resulting in a powder or filter cake, which can be further processed to briquets or pellets. In the latter case, the pre-treatment may comprise mixing black mass with other compounds, not originating from Li-ion batteries or their waste, to produce those briquets or pellets. The exact composition may vary significantly, depending on producer or application. However, for the purpose of the present invention, typical black mass comprising at least carbon materials, lithium, cobalt, nickel, copper, manganese, and iron is used. In a preferred embodiment of the present invention, the black mass comprises amounts of lithium, nickel and cobalt in the ranges of 1-5 wt%, 10-30 wt% and 1-8 wt%, respectively, with respect to the weight of the black mass. In a more preferred embodiment, the black mass comprises amounts of lithium, nickel and cobalt in the ranges of 2-4 wt%, 15-25 wt% and 2-6 wt%, respectively, with respect to the weight of the black mass. The other metals and the carbon materials mentioned above can sum up to 80, 90, or 100% by weight with respect to the weight of the black mass.

[0040] In an embodiment, the black mass subjected to step a) is pre-treated by grinding. Preferably, the grinding of black mass afford particles with a D80 particle size comprised between 1 and 500 pm, more preferably between 10 and 300 pm, even more preferably between 25 and 250 pm as measured by laser diffraction, also known as Laser diffraction spectroscopy, by means of Laser diffraction analyzer such as "Mastersizer 2000" and commercialized by the Malvern Company.

[0041] This technique allows obtaining the particle size and particle size distribution by measuring the intensity of light scattered as a laser beam passes through a dispersed particulate sample.

[0042] Step a) allows to at least partially separate lithium from the black mass, thus obtaining an aqueous solution (A) comprising at least 30% of the starting Li present in the black mass and a solid residue (A’).

[0043] In a preferred embodiment, the black mass comprising Li, Ni and Co fed in step a) is a black mass obtained from the recycling of end-of-use electric vehicle batteries, more preferably from batteries comprising, in addition to Li, Ni and Co, other metallic elements such as Mn, Cu, Fe, P, Si and carbon materials, even more preferably from vehicle lithium batteries comprising Li, Ni, Co, Mn, Cu, Fe, Al, P, Si and carbon materials and a cathode material, wherein the cathode material is selected from LOC (lithium cobalt oxide), such as LiCoCL; LMO (lithium manganese oxide), such as Li2MnC>4; NCA (lithium nickel cobalt aluminium oxide), such as LiNixCoyAlzO2, NMC (lithium nickel cobalt manganese oxide), such as LiNixMnyCozO2, LNMO (lithium nickel manganese spinel), such as LiNio.5Mn1.5O4, and LFP (lithium iron phosphate), such as LiFePO4.

[0044] In an embodiment, the Li comprised in the black mass may originate from the electrolyte and / or the electrode(s) of the batteries used for obtaining the black mass.

[0045] In an embodiment, the Ni and Co comprised in the black mass may originate from the electrode(s), particularly from the cathode of the batteries used for obtaining the black mass.

[0046] In an embodiment, the Ni and Co comprised in the black mass originate from the electrode(s), particularly from the cathode of the batteries used for obtaining the black mass, while Mn, Cu, Fe, Al, P, Si and carbon materials originate from the electrode(s), conducting additives and / or electrolytes of the batteries used for obtaining the black mass.

[0047] Without being bound to theory, the lithium recovered in this step in the first aqueous solution (A) should originate from the free lithium ions present in the battery electrolyte and not from the Li present in the crystalline structure of the active material present in the cathode.

[0048] The black mass may be contacted with an aqueous solution selected from water, including tap water, distilled water or deionized water; or any aqueous liquid medium suitable to remove lithium. Optionally, the aqueous solution may include additional materials, such as, for example, alkali for pH control, surfactants, soaps, and the like. In a preferred embodiment, the aqueous solution is water.

[0049] In this step, at least 30% of the starting Li present in the black mass is recovered in the form of a very pure Li-rich aqueous solution (A) comprising only very small amounts of some impurities, particularly metal impurities such as Ni, Cu, Al and Fe impurities. The metals other than Li are each below a concentration of 0.01 g / L in the Li-rich aqueous solution. In a particular embodiment, at least 30%, at least 35%, at least 40%, at least 45% of the starting Li present in the black mass is recovered in the aqueous solution A. In a preferred embodiment, about 50% of the starting Li present in the black mass is recovered in the aqueous solution A.

[0050] In a particular embodiment, step a) is performed by washing the black mass (see Figures 1 and 2).

[0051] The washing is performed by contacting the black mass with a semi-continuous or continuous flow of the aqueous solution. In a preferred embodiment the aqueous solution for the washing of black mass is water, including tap water, distilled water or deionized water.

[0052] Alternatively, in another particular embodiment, step a) is performed by flotation of the black mass (see figures 3 and 4). The flotation is performed by contacting the black mass with an aqueous solution comprising flotation reagents.

[0053] Examples of flotation reagents are some alcohols, polyglycols, and ethers thereof, fatty acids and sulphonates, preferably methyl isobutyl carbinol and Aero 827 are used.

[0054] In general, the hydrophobic material present in the black mass (such as graphite) is carried out to the surface of the aqueous solution by flotation additives (such as air bubbles) and forms a froth, which is then collected, while the hydrophilic material tends to stay on the bottom of the aqueous solution. Therefore, flotation of BM allows to easily obtain two separate fractions: i) a “floated” fraction mostly comprising graphite and ii) a “sunk” fraction enriched with Li, Ni and Co.

[0055] Particularly, the floated fraction comprises at least 50%, at least 60%, at least 70%, but preferably at least about 80%, even more preferably about 90% of the graphite originally present in the black mass. Thus, the flotation achieves separation of graphite from the majority of metallic elements of the black mass such as Li, Ni and Co. When carrying out the flotation operation in an aqueous medium, and by contacting the black mass with an aqueous solution additionally comprising flotation reagents, it is also possible to recover in pure form most of the Li present in the black mass, in a similar manner to what is obtained during the black mass washing.

[0056] The (%) amount of lithium recovered in the aqueous solution (A) will depend on the starting black mass, as well as on parameters such as residence time and temperature.

[0057] In a particular embodiment, step a) as described in any of the above embodiments is carried out at a temperature comprised between 10-60 °C, preferably between 15-30 °C, more preferably at 20-25 °C.

[0058] In another particular embodiment, the residence time for step a) as described above is comprised between 5 and 200 min, preferably between 10 and 150, more preferably between 10 and 120min, even more preferably for about 60 min.

[0059] In a preferred embodiment, the aqueous solution (A) containing the recovered lithium can be subjected to a precipitation step in order to obtain a lithium product in the form, for example, of a lithium carbonate Li2COs. Any method known by a skilled person can be used to precipitate a lithium product from the aqueous solution.

[0060] Subsequently, the lithium product can be separated from the aqueous solution by filtration or evaporation of the aqueous medium.

[0061] Step b)

[0062] The solid A’ resulting from conducting step a) still contains the remaining lithium not extracted in step a), along with Ni and Co, and other metallic elements such as Mn, Cu and Al.

[0063] Thus, in step b), the solid A’ from step a) is subjected to a first leaching to recover the remaining lithium (not extracted in step a). In addition to that, part of the Ni and Co contained in said solid A’ is also extracted.

[0064] The leaching of the solid A’ is performed with an acid aqueous solution, also referred to as “first aqueous leaching solution”.

[0065] The first aqueous leaching solution used in this step is highly acidic, more particularly the leaching with the acid aqueous solution takes place in a pH ranging between 0 and 3.0, preferably between 0 and 2.0, more preferably between 0.5 and 1.0.

[0066] The leaching step is performed for at least 120 min in order to ensure an effective and quantitative extraction of the lithium contained in the solid residue (A’).

[0067] Under these conditions, the lithium contained in the solid (A’) is gradually leached in the form of water-soluble lithium salt with a yield greater than 85%, preferably greater than 90%, more preferably greater than 92%, based on the lithium present in the solid (A’). In addition to that, part of the nickel and cobalt contained in the solid (A’) is also gradually leached in the form of water-soluble nickel and cobalt salts with a yield between 10 and 30%, preferably between 15 and 25%.

[0068] As a result, an aqueous solution (B) comprising lithium in the form of Li+, as well as a fraction of the nickel and cobalt in the form of Ni2+and Co2+ / Co3+, is obtained, along with a non-leached solid residue (B’) comprising undissolved nickel and cobalt. The aqueous solution (B) can also contain other elements, such as Mn, Al, and Fe which are also dissolved in its cationic form, whereas the solid B’ can also contain undissolved Mn, Cu, Al, and Fe.

[0069] In a particular embodiment, the acid containing in the acid aqueous solution is an inorganic acid, more preferably the inorganic acid is selected from sulphuric acid, hydrochloric acid, nitric acid, hydrofluoric acid and mixtures thereof, provided that the resulting acid aqueous solution has a pH between 0 and 4. In a preferred embodiment, the inorganic acid is hydrochloric acid.

[0070] In a particular embodiment, the pH of the resulting aqueous solution (B) obtained after conducting step b) is in the range 0.6-3.

[0071] In a particular embodiment, the weight ratio between the inorganic acid and the solid (A’) is comprised between 1 : 10 and 1 : 1, preferably between 1 :5 and 1 :2, more preferably is about 1 :3.

[0072] In a particular embodiment, the leaching is performed at a temperature comprised between 10 °C and 50 °C, preferably between 20 °C and 40 °C, more preferably of about 30 °C.

[0073] In a particular embodiment, the leaching is performed during a time comprised between 5 min and 12 hours, preferably between 30 min and 6 hours, more preferably between 1 hour and 3 hours, even more preferably for about 2 hours.

[0074] In an embodiment, the leaching is performed at a temperature as defined in any of the above embodiments during a time as defined in any of the above embodiments.

[0075] Step c)

[0076] In step c), the pH of the aqueous solution (B) resulting from step b) is adjusted until a value comprised in the range 3.5 - 6.5 (upper and lower limits included). As a result, a solid residue (C’) precipitates due to the change of pH, whereas the resulting aqueous solution (C) still contains dissolved cations of lithium, nickel and cobalt. The addition of inorganic bases to the aqueous phase (B) is preferred for adjusting the pH. Examples of suitable inorganic bases are metal hydroxides and carbonates, particularly alkali metal hydroxides and carbonates. In an embodiment, the pH is adjusted to the range 3.5 - 5.5, preferably 3.5 - 5, more preferably, 3.5 - 4.5, even more preferably to about 4.

[0077] In another particular embodiment, the inorganic base is selected from LiOH, NaOH, KOH, RbOH, CsOH, Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3. The most preferred base is Na2COs. It has been observed that with the use of Na2COs the separation of the solid residue C’ from the aqueous solution C is more efficient, especially when such separation is performed by filtration. Preferably the base is added as an aqueous solution.

[0078] In a particular embodiment, step c) is performed at a temperature comprised between 10 °C and 50 °C, preferably between 20 °C and 40 °C , more preferably of about 30 °C.

[0079] In a particular embodiment, step c) is performed during a time comprised between 5 min and 12 hours, preferably between 30 min and 6 hours, more preferably between 1 hour and 3 hours, even more preferably for about 2 hours.

[0080] In an embodiment, step c) is performed at a temperature as defined in any of the above embodiments during a time as defined in any of the above embodiments.

[0081] In a particular embodiment, when metal hydroxides and carbonates are used as inorganic bases, the solid residue (C’) comprises a mixture of hydroxide / carbonate of Al and Fe. This step is particularly advantageous as it allows to separate mostly of undesired metal impurities, particularly copper, as insoluble species.

[0082] Preferably, these metal impurities are readily separated from the aqueous solution C by filtration.

[0083] Thus, the resulting aqueous solution (C) comprises Li, Ni and Co. In a particular embodiment, the aqueous solution (C) additionally comprises Mn, Al and Fe.

[0084] The aqueous solution (C) is then fed to the next step (Co-selective solvent extraction).

[0085] Step d)

[0086] The aqueous solution (C) resulting from step c) is then subjected to a liquid-liquid extraction step in order to extract the cobalt contained therein along with some metal impurities, whereas lithium and nickel remain in the aqueous solution.

[0087] This step includes the extraction of cobalt by putting in contact the aqueous solution (C) obtained in step c) with a Co-selective organic acid extractant, preferably under countercurrent conditions.

[0088] During this step, cobalt is selectively and gradually loaded into the organic liquid phase, releasing H+ions according to the following chemical reactions:

[0089] Co2++ 2HR C0R2 + 2H+

[0090] Co3++ 3HR C0R3 + 3H+wherein HR represents the organic acid extractant and C0R2 and C0R3 refer to the cobalt- loaded organic solution containing the extracted cobalt.

[0091] The aqueous solution (C) fed to the extraction step has a pH between 2.5 and 5.5, preferably between 3.5 and 4.5, as mentioned above. However, during the cobalt extraction, the obtained aqueous solution increases its acidity. This occurs because the protons are transferred from the organic phase to the aqueous phase throughout the extraction step according to the above reactions. An alkaline agent can be added to slightly increase the pH and then returning it to a value similar to the aqueous solution (C), preferably between 3.5 and 4.5. Examples of alkaline agents include a base selected from LiOH, NaOH, KOH, RbOH, CsOH, Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3, preferably NaOH.

[0092] To attain the best selective extraction, acidic conditions are used so that, cobalt and those cations having greater affinity for the organic acid extractant, such as iron, aluminium and manganese, can be extracted.

[0093] Therefore, an organic extraction phase (D) containing dissolved cobalt is obtained along with an acidic aqueous phase (D’) containing lithium and nickel.

[0094] The Co-selective organic acid extractant is preferably selected from alkyl phosphoric acids, alkyl phosphonic acids, alkyl phosphinic acids, alkyl amines, oximes, and mixtures thereof. Examples include, but are not limited to, di-(2-ethylhexyl) phosphoric acid (also referred as to D2EPHA), di-(2-etylhexyl) phosphonic acid, bis-(2,4,4-trimethyl-pentyl) phosphinic acid, trioctylamine or (2-hydroxy- 5 -nonylacetophenone oxime). More preferably, the organic extractant is selected from phosphoric acids and mixtures of alkyl phosphonic acids and alkyl phosphinic acids. Commercially available organic extractants included in the list above are, for example, Cyanex® 272, Cyanex® 572, LIX 84-IC, Alamine® 336 and the like. Cyanex® 572 is preferred due to the high extraction efficiency.

[0095] For its use in cobalt extraction, the organic acid extractant is preferably dissolved in an organic compound or in a mixture of organic compounds originating from an oil moiety, such as C11-C14 paraffins and naphthalenes, e.g., kerosene. Organic solvents, such as methyl iso-butyl ketone (MIBK), tributyl phosphate (TBP), 1 -heptanol, di-isopropyl ether (DIPE) and mixtures thereof, can also be used.

[0096] The weight proportion of the organic acid extractant in the organic compound or solvent ranges between 5 and 75%, and preferably between 30 and 50 wt%.

[0097] In a particular embodiment, the volumetric ratio between organic phase and aqueous phase is comprised between 5: 1 and 1 :5, preferably between 2:1 and 1 :2, more preferably said ratio is about 1 : 1.

[0098] In a particular embodiment, step c) is performed at a temperature comprised between 10 °C and 50 °C, preferably between 20 °C and 40 °C, more preferably of about 30 °C.

[0099] This extraction step may be advantageously performed in several stages, for example said extraction step is repeated up to five times. Particularly, after a first extraction, the aqueous phase is separated and contacted again with another portion of the at least one Co-selective organic extractant. In an embodiment, the extraction is performed once, twice, three times, four times, five times, preferably once or twice, more preferably twice. Thus, after conducting the extraction step d), a cobalt-loaded organic phase (D) is formed, as well as an acid aqueous extraction phase (D’) containing lithium and nickel dissolved therein.

[0100] However, said cobalt-loaded organic phase (D) still contains other co-extracted entrained metal impurities, such as iron, aluminum and manganese. Thus, in a particular embodiment, said cobalt-loaded organic phase (D) may be optionally subjected to a first stripping step comprising the treatment of said organic phase with an acidic aqueous solution.

[0101] The conditions of this first stripping step allow metal impurities such as iron, aluminum and manganese, extracted with the cobalt during the extraction step, not to be stripped from the organic phase, thus only the cobalt is stripped and, therefore, a purified aqueous solution of cobalt is obtained along with an organic stream containing said other metal impurities.

[0102] For such optional stripping, an acidic aqueous solution (also denominated “stripping solution”), preferably a sulphuric acid aqueous solution, is employed.

[0103] In an embodiment, the volumetric ratio between organic phase and stripping solution is comprised between 10: 1 and 1 : 1, preferably between 6: 1 and 2: 1, more preferably said ratio is about 4: 1.

[0104] The optional stripping may be repeated various times. Particularly, after a first stripping, the organic phase is separated and contacted again with another portion of the stripping solution. In an embodiment, the stripping is performed once, twice, three times, four times, five times. Preferably, the stripping is performed 2 to 4 times.

[0105] The aqueous phase (D’) containing Li and Ni, resulting from the extraction step, may be further subjected to additional steps to separation Li from Ni. In an embodiment, this optional separation may be carried out by selective precipitation and / or extraction.

[0106] In an embodiment, the separation of Li from Ni is performed by selective precipitation. Specifically, the pH of the aqueous phase (D’) is raised to a range between 7 and 9 (upper and lower limits included), preferably to 8.

[0107] Any skilled in the art would know how to raise the pH, for example by using a base such as NaOH. In this way, Ni is recovered in the form of nickel hydroxide while Li remains in the aqueous phase.

[0108] In another embodiment, the separation of Li from Ni is performed by solvent extraction. In this particular case, the aqueous solution (D’) resulting from step d) is then subjected to a liquid-liquid extraction step in the presence of a nickel organic extractant, so as the nickel contained therein is extracted, whereas lithium remains in the aqueous solution.

[0109] For this extraction step to take place, the pH of the aqueous solution should be adjusted to the range 5-7, preferably to about 6. The organic extractant to be used in this extraction step can be those mentioned above for the cobalt extraction. Preferable is the use of di-(2-ethylhexyl) phosphoric acid (also referred as to D2EPHA), di-(2-etylhexyl) phosphonic acid or bis-(2,4,4-trimethyl-pentyl) phosphinic acid, for example those commercially available under Cyanex® 272 and Cyanex® 572.

[0110] Step e)

[0111] The solid (B’) resulting from the leaching step b) contains the non-leached nickel and cobalt.

[0112] Thus, in step e), the solid (B’) from step a) is subjected to a second leaching to recover the nickel and cobalt. The leaching of the solid (B’) is also performed with an acid aqueous solution, also referred to as second aqueous leaching solution.

[0113] The second aqueous leaching solution used in this step is also highly acid, more particularly the pH of the acid aqueous solution ranges between 0 and 2.3, preferably between 0 and 2, more preferably between 0.2 and 0.5.

[0114] Said second aqueous leaching solution comprises a mixture of an inorganic acid and an oxidizing agent. The presence of the oxidizing agent allows regulating the potential of the reaction and it also prevents other species from precipitation. In a particular embodiment, the oxidizing agent is characterized by a standard potential E° greater than +0.96 V, preferably greater than +1.00 V, more preferably greater than +1.10 V, even more preferably greater than +1.20 V. Alternatively, the oxidizing agent is characterized by a standard potential E° greater than +0.96 V and lower than +2.00 V, preferably greater than +1.00 V and lower than +1.90 V, more preferably greater than +1.10 V and lower than +1.85V, even more preferably greater than +1.20 V and lower than +1.80 V.

[0115] The standard reduction potential, E°, as known in the art, is measured in volts and is relative to the standard hydrogen electrode (SHE), at a temperature of 298.15 K (25.00 °C), a concentration (activity) of 1 mol / L for each aqueous or amalgamated (mercury- alloyed) species, unit activity for each solvent and pure solid or liquid species, and absolute partial pressure of 101.325 kPa (1.00000 atm) for each gaseous reagent.

[0116] Preferably, the oxidizing agent is NaClO or H2O2, more preferably is NaClO.

[0117] In an embodiment, the inorganic acid comprised in the second aqueous leaching solution is selected from hydrochloric acid, sulphuric acid, and nitric acid, preferably hydrochloric acid. In a preferred embodiment, hydrochloric acid is used as an aqueous solution.

[0118] In a preferred embodiment, the inorganic acid is selected from hydrochloric acid, sulphuric acid, and nitric acid and the the oxidizing agent is characterized by a standard potential E° greater than +0.96 V and lower than +2.00 V or any of the corresponding preferred E° ranges.

[0119] The weight ratio between the inorganic acid and the oxidizing agent may vary depending on the amount and type of black mass. In an embodiment, the weight ratio between the inorganic acid and the oxidizing agent is comprised between 5: 1 and 1 : 1, preferably between 3: 1 and 1 : 1, more preferably said ratio is about 1.6:1.

[0120] When hydrochloric acid is used as inorganic acid and NaClO as oxidizing agent, the preferred weight ratio is between 2: 1 and 1.2: 1, more preferably is 1.6: 1.

[0121] In a particular embodiment, the weight ratio between the inorganic acid, preferably hydrochloric acid, and the solid (B’) is comprised between 1 : 10 and 1 : 1, preferably between 1 :5 and 1 :1, more preferably between 1 :2 and 1 : 1, and even more preferably is 0.8: 1.

[0122] In a particular embodiment, the weight ratio between the oxidizing agent, preferably NaClO, and the solid (B’) is comprised between 1 :10 and 1: 1, preferably between 1 :5 and 1 : 1, more preferably is about 1 :2.

[0123] This second leaching is carried out at a temperature between 25 and 60°C to obtain an aqueous solution (E) and a solid residue (E’).

[0124] In a particular embodiment, the aqueous solution (E) comprises nickel and cobalt (see figures 1 and 3), whereas the solid residue (E’) may also comprise Co (see figures 2 and 4).

[0125] In a particular embodiment, the second leaching is carried out at a temperature between 40-60°C (figures 1 and 3). Under these conditions, the nickel and cobalt contained in the solid (B’) are gradually leached in the form of water-soluble nickel and cobalt salts with a yield greater than 90%, preferably greater than 95%, more preferably greater than 98% for each one, based on the nickel and cobalt present in the solid (B’).

[0126] As a result, an aqueous solution (E) comprising nickel and cobalt in the form of Ni2+and Co2+ / Co3+, is obtained, along with a non-leached solid residue (E’) comprising undissolved impurities. The aqueous solution (E) can also contain other metal impurities, such as Cu, Al, and Fe which are also dissolved in its cationic form.

[0127] The solid residue (E’) may also contain Co depending on the leaching conditions such as temperature, pH and weight proportions of inorganic acid and oxidizing reagent. The Co present in the solid residue (E’) may be extracted according to steps h) to j) below.

[0128] The solid residue (E’) additionally contain the graphite present in the starting BM in the process where said BM is subjected to washing in step a).

[0129] In a particular embodiment, the second leaching is performed during a time comprised between 5 min and 12 hours, preferably between 30 min and 6 hours, more preferably between 1 hour and 3 hours, even more preferably for about 2 hours. This ensures an effective and quantitative extraction of the nickel and cobalt, contained in the solid residue (B’).

[0130] Step f) In step f), the pH of the aqueous solution (E), resulting from step e) is adjusted in the range 4.5 - 6.5 to obtain an aqueous solution (F) and a solid residue (F’).

[0131] When the pH of the aqueous solution (E) is adjusted, as a result, a solid residue (F’) precipitates due to the change of pH, whereas the resulting aqueous solution (F) still contains dissolved cations of nickel and cobalt. The addition of inorganic bases to the aqueous phase (E) is preferred for adjusting the pH.

[0132] Examples of suitable inorganic bases to adjust the pH of solution (E) are metal hydroxides and carbonates, particularly alkali metal hydroxides and carbonates.

[0133] In an embodiment, the pH of solution (E) is adjusted to the range 4.0 - 6.5, preferably 5.0 - 6.5, more preferably, 5.5 - 6.5, even more preferably to about 6.

[0134] In a particular embodiment, the base is selected from LiOH, NaOH, KOH, RbOH, CsOH, Li2CO3, Na2COs, K2CO3, Rb2CO3, and CS2CO3. The most preferred base is Na2CO3. In a similar manner to step c), it has been observed that the use of Na2CO3 is beneficial to the separation of the solid residue F’ from the aqueous solution F, especially when such separation is performed by filtration. Preferably the base is added as an aqueous solution.

[0135] In a particular embodiment, step f) is performed at a temperature comprised between 10 °C and 50 °C, preferably between 20 °C and 40 °C, more preferably of about 30 °C.

[0136] In a particular embodiment, step f) is performed during a time comprised between 5 min and 12 hours, preferably between 30 min and 6 hours, more preferably between 1 hour and 3 hours, even more preferably for about 2 hours.

[0137] In an embodiment, step f) is performed at a temperature as defined above during a time as defined above.

[0138] In a particular embodiment, when metal hydroxides and carbonates are used as inorganic bases for adjusting the pH of solution (E), the resulting solid residue (F’) comprises >90% of a mixture of hydroxide / carbonates of Cu, Al and Fe. This step allows to further eliminate most of the remaining undesired metal impurities, particularly copper and aluminium, as insoluble species; preferably the solid residue (F)’ is readily separated from the aqueous solution (F) by filtration.

[0139] The aqueous solution (F) mostly comprises Ni and Co. In a particular embodiment, the aqueous solution (F) additionally comprises trace amounts of Li, Mn, Al, Cu and Fe, wherein trace amounts are defined as amounts up to 0.1 g / L.

[0140] The aqueous solution (F) is then fed to the next step (Ni- and Co-selective solvent extraction).

[0141] Step g)

[0142] The aqueous solution (F) comprising Ni and Co, resulting from step f) is then subjected to a second liquid-liquid extraction step in order to extract the cobalt and nickel contained therein. In a particular embodiment, the aqueous solution (F) is subjected to a second liquid-liquid extraction step in order to extract the cobalt and nickel contained therein (see figures 1 and 3), whereas metal impurities remain in the aqueous solution which is optionally recirculated into previous steps of the process.

[0143] This step includes the extraction of cobalt and nickel by putting in contact the aqueous solution (F) obtained in step f) with a Ni- and Co-selective organic extractant, preferably under counter-current conditions.

[0144] During this step, cobalt and nickel are selectively and gradually loaded into the organic liquid phase, releasing H+ions.

[0145] The aqueous solution (F) fed to the extraction step has a pH between 4 and 6.5, preferably between 5.5 and 6.5, as mentioned above. However, during the nickel and cobalt extraction, the obtained aqueous solution increases its acidity. This occurs because the protons are transferred from the organic phase to the aqueous phase throughout the extraction step. An alkaline agent can be added to slightly increase the pH and then returning it to a value similar to the aqueous solution (F), preferably between 5.5 and 6.5. Examples of alkaline agents include a base selected from LiOH, NaOH, KOH, RbOH, CsOH, Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3, preferably NaOH.

[0146] Therefore, an organic extraction phase (G) containing dissolved nickel and cobalt is obtained along with an acid aqueous phase (G’) containing metal impurities, which is optionally recirculated into previous steps of the process.

[0147] The Ni- and Co-selective organic extractant is preferably selected from alkyl phosphoric acids, alkyl phosphonic acids, alkyl phosphinic acids, alkyl amines, oximes, and mixtures thereof. Examples include, but are not limited to, di-(2-ethylhexyl) phosphoric acid (also referred as to D2EPHA), di-(2-etylhexyl) phosphonic acid, bis-(2,4,4-trimethyl-pentyl) phosphinic acid, trioctylamine or (2-hydroxy- 5 -nonylacetophenone oxime). More preferably, the organic extractant is selected from phosphoric acids and mixtures of alkyl phosphonic acids and alkyl phosphinic acids. Commercially available organic extractants included in the list above are, for example, Cyanex® 272, Cyanex® 572, LIX 84-IC, Alamine® 336 and the like. Cyanex® 572 is preferred due to the high extraction efficiency.

[0148] For its use in nickel and cobalt extraction, the organic extractant is preferably dissolved in an organic compound (or solvent) or in a mixture of organic compounds (or solvents) originating from an oil moiety, such as C11-C14 paraffins and naphthalenes, e.g., kerosene. Organic solvents, such as methyl iso-butyl ketone (MIBK), tributyl phosphate (TBP), 1 -heptanol, di-isopropyl ether (DIPE) and mixtures thereof, can also be used.

[0149] The weight proportion of the organic extractant in the organic compound or solvent ranges between 5 and 75%, and preferably between 30 and 50 wt%. In a particular embodiment, the volumetric ratio between organic phase and aqueous phase is comprised between 5: 1 and 1 :5, preferably between 2: 1 and 1 :2, more preferably said ratio is about 1 : 1.

[0150] In a particular embodiment, step g) is performed at a temperature comprised between 10 °C and 50 °C, preferably between 20 °C and 40 °C, more preferably of about 30 °C.

[0151] This second extraction step may be advantageously performed in several stages, for example said extraction step is repeated up to ten times. Particularly, after a first extraction, the aqueous phase is separated from the organic phase and contacted again with another portion of the at least one Ni- and Co-selective organic extractant.

[0152] In an embodiment, the extraction is performed between 1-10 times, preferably between 2-8 times, more preferably between 3-5 times. All portions of organic phase are then mixed together.

[0153] Thus, after conducting the extraction step g), a nickel- and cobalt-loaded organic phase (G) is formed, as well as an acidic aqueous extraction phase (G’) containing metal impurities dissolved therein which is optionally recirculated into previous steps of the process.

[0154] However, said nickel- and cobalt-loaded organic phase (G) can still contains few amounts of co-extracted entrained metal impurities, such as iron, copper, aluminum and manganese. Thus, in a particular embodiment, said nickel- and cobalt-loaded organic phase (G) can be optionally subjected to a second stripping step comprising the treatment of said organic phase (G) with an acid aqueous solution.

[0155] The conditions at this second stripping step allow the remaining metal impurities being extracted with the nickel and cobalt at the second extraction step, not to be stripped from the organic phase, thus only the nickel and cobalt are stripped and, therefore, a purified aqueous solution of nickel and cobalt is obtained along with an organic stream containing said metal impurities.

[0156] For such optional second stripping, an acidic aqueous solution (also denominated “second stripping solution”), preferably a sulphuric acid aqueous solution, is employed.

[0157] In an embodiment, the volumetric ratio between organic phase (G) and second stripping solution is comprised between 10: 1 and 1 :1, preferably between 6: 1 and 2: 1, more preferably said ratio is about 4: 1.

[0158] The optional second stripping may be repeated various times to increase the removal of metal impurities. Particularly, after the first stripping, the organic phase is separated and contacted again with another portion of the second stripping solution. In an embodiment, the stripping is performed once, twice, three times, four times, five times. Preferably, the stripping is performed 2 to 4 times, more preferably 3 or 4 times.

[0159] As a result, an aqueous solution of nickel and cobalt (STI) is obtained along with an organic stream (ST2) containing said metal impurities. Step h)

[0160] When the solid residue (E’) resulting from conducting step e) comprises Co, said solid (E’) can optionally be subjected to a third leaching to recover the remaining cobalt not extracted in said step e) (see figures 2 and 4).

[0161] The leaching of the solid (E’) is performed with an acidic aqueous solution, also referred to as third aqueous leaching solution.

[0162] The third aqueous leaching solution used in this step is highly acidic, more particularly the leaching with the acid aqueous solution takes place in a pH ranging between 0 and 2.3, preferably between 0 and 2, more preferably between 0.5 and 1.0.

[0163] The leaching step is performed for at least 120 min in order to ensure an effective and quantitative extraction of the cobalt contained in the solid residue (E’).

[0164] Under these conditions, the cobalt contained in the solid (E’) is gradually leached in the form of water-soluble cobalt salt with a yield greater than 85%, preferably greater than 90%, more preferably greater than 92%, based on the cobalt present in the solid (E’).

[0165] As a result, an aqueous solution (H) comprising cobalt in the form of Co2+ / Co3+, is obtained, along with a non-leached solid residue (H’) comprising metal impurities, as well as the graphite present in the starting BM when this is subjected to washing in step a). The aqueous solution (H) can also contain minor trace amounts of other elements, such as Mn, Al, and Fe which are also dissolved in its cationic form.

[0166] The pH of the aqueous solution (H) is acidic due to the use of the third acid aqueous solution. In a particular embodiment, the pH of the aqueous solution (H) is lower than 2, preferably comprised between 0 and 2.

[0167] In a particular embodiment, the acid containing in the third aqueous leaching solution is an inorganic acid, more preferably the inorganic acid is selected from sulphuric acid, hydrochloric acid, nitric acid, hydrofluoric acid and mixtures thereof, provided that the resulting acid aqueous solution has a pH between 0 and 2. In a preferred embodiment, the inorganic acid is hydrochloric acid.

[0168] In a particular embodiment, the weight ratio between the inorganic acid, preferably hydrochloric acid, and the solid (E’) is comprised between 1 : 10 and 1 : 1, preferably between 1 :5 and 1 : 1, more preferably between 1 :2 and 1 : 1 and even more preferably is 0.8: 1.

[0169] In a particular embodiment, said third aqueous leaching solution further comprises an oxidizing agent. The presence of the oxidizing agent allows regulating the potential of the reaction and it also prevents other species from precipitation. Preferably, the oxidizing agent is NaClO or H2O2, more preferably is NaClO.

[0170] In an embodiment, the weight ratio between the inorganic acid, and the oxidizing agent is comprised between 5: 1 and 1 : 1, preferably between 3: 1 and 1 : 1, more preferably said ratio is about 1.6:1. When hydrochloric acid is used as inorganic acid and NaClO as oxidizing agent, the preferred weight ratio is between 2: 1 and 1.2: 1, more preferably is 1.6: 1.

[0171] In a particular embodiment, the weight ratio between the oxidizing agent, preferably NaClO, and the solid (E’) is comprised between 1 :10 and 1: 1, preferably between 1 :5 and 1 : 1, more preferably is about 1 :2.

[0172] In a particular embodiment, the leaching is performed at a temperature comprised between 10 °C and 50 °C, preferably between 20 °C and 40 °C, more preferably of about 40 °C.

[0173] In a particular embodiment, the leaching is performed during a time comprised between 5 min and 12 hours, preferably between 30 min and 6 hours, more preferably between 1 hour and 3 hours, even more preferably for about 2 hours.

[0174] In an embodiment, the leaching is performed at a temperature as defined in any of the above embodiments during a time as defined in any of the above embodiments.

[0175] Step i)

[0176] In step i), the pH of the aqueous solution (H) resulting from step h) is adjusted until a value comprised in the range 2.5 - 6.0 (upper and lower limits included). As a result, a solid residue (I’) precipitates due to the change of pH, whereas the resulting aqueous solution I still contains dissolved cations of cobalt. The addition of inorganic bases to the aqueous phase H is preferred for adjusting the pH. Examples of suitable inorganic bases are metal hydroxides and carbonates, particularly alkali metal hydroxides and carbonates. In an embodiment, the pH is adjusted to the range 2.5 - 6.0, preferably 3 - 5, more preferably, 3.5 - 4.5, even more preferably to about 4.

[0177] In another particular embodiment, the inorganic base is selected from LiOH, NaOH, KOH, RbOH, CsOH, Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3. The most preferred base is Na2CO3. It has been observed that with the use of Na2CO3the separation of the solid residue I’ from the aqueous solution (I) is more efficient, especially when such separation is performed by filtration. Preferably the base is added as an aqueous solution.

[0178] In a particular embodiment, step i) is performed at a temperature comprised between 10 °C and 50 °C, preferably between 20 °C and 40 °C, more preferably of about 30 °C.

[0179] In a particular embodiment, step i) is performed during a time comprised between 5 min and 12 hours, preferably between 30 min and 6 hours, more preferably between 1 hour and 3 hours, even more preferably for about 2 hours.

[0180] In an embodiment, step i) is performed at a temperature as defined in any of the above embodiments during a time as defined in any of the above embodiments.

[0181] In a particular embodiment, the solid residue (I’), resulting from the adjustment of the pH, comprises a mixture of metal impurities, preferably in the form of hydroxides or carbonates depending on the inorganic base used for adjusting the pH. This step is particularly advantageous as it allows to separate mostly of undesired metal impurities. Preferably, these metal impurities are readily separated from the aqueous solution (I) by filtration.

[0182] Thus, the resulting aqueous solution (I) comprises cobalt. In a particular embodiment, the aqueous solution (I) additionally comprises trace amounts of metal impurities.

[0183] The aqueous solution (I) comprises almost exclusively cobalt and is then fed to the next step (Co-selective solvent extraction).

[0184] Step j)

[0185] This step can be conducted under the conditions of step d). In particular, Co is extracted from the aqueous solution (I) with at least one Co-selective organic solvent to obtain an organic phase (J) comprising Co and an aqueous phase (J’) which can be recirculated into previous steps of the process.

[0186] The Co-selective organic solvents, temperature, pH, volumetric ratio conditions and the optional stripping step already described in step d) above also apply to step j).

[0187] In a further embodiment, the Co present in the organic phase (J) is isolated as a pure cobalt salt by solvent removal.

[0188] Thus, in a particular embodiment, the cobalt-loaded organic phase (J) can be optionally subjected to a second stripping step comprising the treatment of said organic phase (J) with an acid aqueous solution.

[0189] The conditions at this second stripping step allow the remaining metal impurities being extracted with the cobalt at the third extraction step, thus only the cobalt is stripped and, therefore, a purified aqueous solution of cobalt (ST3) is obtained along with an organic stream containing said metal impurities (ST4).

[0190] For such optional third stripping, an acidic aqueous solution (also denominated “third stripping solution”), preferably a sulphuric acid aqueous solution, is employed.

[0191] In an embodiment, the volumetric ratio between organic phase (J) and third stripping solution is comprised between 10: 1 and 1 :1, preferably between 6: 1 and 2: 1, more preferably said ratio is about 4: 1.

[0192] Isolation of Li, Ni and Co

[0193] The Li, Ni and Co present in aqueous solutions (A), (D’) and in those aqueous solutions after the optional stripping from organic phases (D), (G), and (J), may be isolated according to procedures known to a skilled person, e.g. by precipitation of said metals as insoluble salts in water, preferably as hydroxides or carbonates.

[0194] Thus, in an embodiment, the process of the invention includes an additional isolation step of Li, Ni and / or Co. In particular, the isolation step may be carried out by addition of an alkali metal hydroxide or a water-soluble alkali metal carbonate to precipitate Li, Ni and / or Co as hydroxides or carbonates. The corresponding Li, Ni and / or Co hydroxides or carbonates are preferably separated by filtration and dried.

[0195] Thus, in another embodiment, the process of the invention further includes the isolation of Li, Ni and / or Co salts as described previously.

[0196] Alternatively, the Li, Ni and / or Co salts are not isolated and are comprised in ready-to- use aqueous solutions (for example, as metal sulphates) for the fabrication of cathode active materials, thereby avoiding extra steps as compared to the required dissolution of commercial, fresh batches of salts.

[0197] Uses

[0198] Another aspect of the invention refers to the use of the recovered Li, Ni and / or Co as defined above in the fabrication of cathode active materials (CAM) for LIBs. The purity of the recovered Li, Ni and / or Co exceeds 95%, or even 99%. The process of the first aspect of the invention provides Li, Ni and / or Co in the form of salts (preferably in solution).

[0199] The Li, Ni and / or Co recovered from the process of the invention are preferably isolated as individual pure salts, such as carbonate or hydroxide salts, or mixtures of said salts, then subjected to well-known steps of fabrication of CAMs. Fabrication procedures starting from Li, Ni and / or Co salts have been extensively reported (for example in W02019002116A1 and references therein).

[0200] In an embodiment, a second aspect of the invention refers to the use of the recovered Li in the aqueous solution A (isolated as lithium salt) and / or in the aqueous solution D’, the latter (containing Ni and Li) being preferably subjected to selective separation of Li as already described and Li being isolated as salt, in the fabrication of lithium-containing cathode active materials. Preferably, the recovered Li as in the previous embodiment is used in the fabrication of LCO (lithium cobalt oxide), such as LiCoCL; LMO (lithium manganese oxide), such as Li2MnC>4; NCA (lithium nickel cobalt aluminium oxide), expressed as LiNixCoyAlzO2, NMC (lithium nickel cobalt manganese oxide), expressed as LiNixMnyCozCL, LNMO (lithium nickel manganese spinel), expressed as LiNiMnCU, such as LiNio.5Mn1.5O4, and LFP (lithium iron phosphate), such as LiFePO4.

[0201] In an embodiment, a second aspect of the invention refers to the use of the recovered Ni in the aqueous solution D’ (containing Ni and Li), being this preferably subjected to selective separation and isolation of Ni as already described, and / or in the organic phases G, being any of these preferably purified by stripping as already described and Ni being isolated as salt, in the fabrication of Ni-containing cathode active materials. Preferably, the recovered Ni as in the previous embodiment is used in the fabrication of NCA (lithium nickel cobalt aluminium oxide), expressed as LiNixCoyAlzO2, NMC (lithium nickel cobalt manganese oxide), expressed as LiNixMnyCozO2, LNMO (lithium nickel manganese spinel), expressed as LiNiMnO4, such as LiNio.5Mn1.5O4, or LMR (lithium nickel rich manganese oxide) expressed as LiNixMnyO2. In an embodiment, a second aspect of the invention refers to the use of the recovered Co in the aqueous solution D and / or J, being any of these preferably purified by stripping as already described and the Co isolated as salt, in the fabrication of Co-containing cathode active materials. Preferably, the recovered Co as in the previous embodiment is used in the fabrication of LCO (Lithium Cobalt Oxide), such as LiCoO?, NMC (Lithium Nickel Manganese Cobalt Oxide) expressed as LiNixMnyCozO2, or NCA (lithium nickel cobalt aluminium oxide), expressed as LiNixCoyAlzO2.

[0202] In another embodiment, a second aspect of the invention refers to the use of the recovered Ni and Co in the organic phase G, being any of these preferably purified by stripping as already described and Ni and Co isolated as salts, in the fabrication of Ni and / or Cocontaining cathode active materials.

[0203] In an embodiment, the amount of recovered Li, Ni and / or Co in any of the above solutions containing Li, Ni and / or Co can be adjusted by adding a certain amount of pre-formed Li, Ni and / or Co salts with purity of >98% (such commercial Li, Ni and / or Co salts are widely available). For example, up to 100% of the recovered Ni and Co may be used and adequate “dopant” amounts of commercial Ni and Co may be added to the recovered metals to obtain the stoichiometric ratio 6:2:2 for a NMC622. Commercial NiSCU 7H2O and COSO4 7H2O may be employed forthat purpose. Li2COs and LiOH H2O may be used as lithium sources or “dopants”. This ensures a stoichiometric formation of the cathode active material (for example a NMC material) and may even improve the cathode performance. The amounts of pre-formed Li, Ni and / or Co salts (such as that of commercial salts) may be lower than 10 wt.%, preferably lower than 5 wt.% (compared to the total weight of each metal in the CAM). The purity of the commercial (pre-formed) Li, Ni and / or Co salts is >98%, preferably >99%.

[0204] In an embodiment, the second aspect of the invention refers to the use of recovered Ni, Co, and / or Li according to the first aspect, wherein part of or the totality of the recovered Ni, Co, and / or Li, is used in the manufacture of a NMC622 or a NMC811 cathode. In a particular embodiment, 80-100 wt.%, preferably 90-100 wt.%, more preferably about 100 wt.% of the recovered Ni is used in the manufacture of a NMC622 or a NMC811 cathode. As said earlier, pre-formed NiSCU 7H2O (>98% purity) may be added to the recovered Ni in the required remainder wt.%. In another particular embodiment, 20-100 wt.%, preferably 20-85 wt.%, more preferably 20-70 wt.% of the recovered Co is used in the manufacture of a NMC622 or a NMC811 cathode. As said earlier, pre-formed COSO4 7H2O (>98% purity) may be added to the recovered Co in the required remainder wt.%. In a particular embodiment, 0-100 wt.%, of the recovered Li is used in the manufacture of a NMC622 or a NMC811 cathode. In an embodiment, only pre-formed Li2CC>3 and / or LiOH H2O (>98% purity) are used as lithium salt in the manufacture of a NMC622 or a NMC811 cathode. In another embodiment, 100 wt.% of the recovered Li is used in the manufacture of a NMC622 or a NMC811 cathode. In a particular embodiment, the second aspect of the invention refers to the use of recovered Ni and Co according to the first aspect in the manufacture of a NMC622 or a NMC811 cathode, wherein part of or the totality of the recovered Ni and Co and, additionally, pre-formed Li2CC>3 and / or LiOH H2O (>98% purity) are used. In a particular embodiment, the second aspect of the invention refers to the use of recovered Ni and Co according to the first aspect in the manufacture of a NMC622 or a NMC811 cathode, wherein the totality of the Ni recovered according to the first aspect, between 20 and 70 wt.% of the Co recovered according to the first aspect and, additionally, 100wt.% of pre-formed Li2COs and / or LiOH H2O (>98% purity) are used. In a particular embodiment, the second aspect of the invention refers to the use of recovered Ni and Co according to the first aspect in the manufacture of a NMC622 cathode, wherein the totality of the Ni recovered according to the first aspect, between 20 and 30 wt.%, preferably between 23 and 25 wt.% of the Co recovered according to the first aspect and, additionally, 100wt.% of pre-formed Li2COs and / or LiOH H2O (>98% purity) are used. In another particular embodiment, the second aspect of the invention refers to the use of recovered Ni and Co according to the first aspect in the manufacture of a NMC811 cathode, wherein the totality of the Ni recovered according to the first aspect, between 60 and 70 wt.%, preferably between 62 and 66 wt.% of the Co recovered according to the first aspect and, additionally, 100wt.% of pre-formed Li2CC>3 or LiOH H2O (>98% purity) are used. The wt.% values are referring to the specific wt.% of metal with respect to the total amount of each metal in the cathode.

[0205] The use of part of Ni, Co and / or Li recovered according to the first aspect mixed with pre-formed salts of Ni, Co and / or Li (>98% purity) may additionally improve the performance of the cathode active material as compared to an ex novo made CAM (one made only with commercial, pre-formed and pure salts), for example in terms of capacity discharge at various C / rates (such as C / 10, C / 5, etc.). In some embodiments, the so- obtained CAM (such as a NMC622) is characterized by a discharge capacity of at least 150 mAh / g, at least 155 mAh / g, at least 160 mAh / g.

[0206] EXAMPLES

[0207] Particle size measurements

[0208] The particle size measurements, and in particular D80, were carried out by laser diffraction spectroscopy using a Laser diffraction analyser commercialised by the Malvern Company.

[0209] As previously mentioned above, D80 refers to the average diameter of a particle whereby 80% of the population of particles have a diameter below a certain value or within a specific range.

[0210] Sample humidity

[0211] In order to calculate the humidity of the sample, the wet sample was weighed and then left to dry in an oven for 24 hours until completely dry. Subsequently, the dry sample was weighed and the moisture content was calculated by the difference in weight between the wet and dry sample.

[0212] Real and Apparent density of black mass (BM)

[0213] Apparent density: for the calculation of the apparent density, the pores of the material are taken into account. It is carried out with a 100 mL test tube, filling it with dry solid up to 100 mL.

[0214] Apparent density = ((test tube weight with solid + empty test tube weight) - empty test tube weight) / test tube volume.

[0215] Real density: for the calculation of the real density, the pores of the material are not included. The real density is measured with a pycnometer.

[0216] Materials and characterization

[0217] The raw material for the process is BM from the recycling of end-of-use electric vehicle batteries.

[0218] The chemical characterization of the BM used in this example is reported in table 1 below.

[0219] Table 1.

[0220] The black mass was previously grounded to be in particulate form, namely D80 particle size of the BM sample was 145 pm.

[0221] The sample humidity was 1.3%.

[0222] The real density and apparent density of the black mass were determined respectively as (4.18 g / cm3) and (0.92 g / cm3).

[0223] Cyanex 572® was purchased from Solvay. In the following procedure, the composition of liquid fractions / streams for each of the process steps was determined as follows:

[0224] - the content of Li, Ni and Co was determined by ICP-OES following well-established procedures known to the skilled person;

[0225] - the content of graphite was determined by the carbon content which was measured by TOC-V CSH technique.

[0226] - the starting and final pH was determined by well-established procedures known to the skilled person;

[0227] In the following procedure, the composition of solid fractions / streams for each of the process steps was determined as follows:

[0228] - Content of Li, Ni and Co: a weighed sample of the solid was digested with aqua regia and the content of the metals in the liquid phase was determined by ICP-OES following well-established procedures known to the skilled person.

[0229] - The content of graphite was determined by the carbon content which was measured by combustion elemental microanalysis technique. This determination is based on a method called "dynamic flash combustion", which involves the combustion of the sample at high temperature in an oxygen atmosphere and the quantification of the resulting gases, being for carbon, as carbon dioxide. In particular, a complete combustion of the sample was done under temperature between 950 °C and 1300 °C and pure oxygen atmosphere, so as conversion of carbon into CO2 took place. The resulting gases were separated by chromatographic column and the carbon content were measured and processed as mentioned above.

[0230] ICP-OES measurements were carried out using a Perkin Elmer Optima 8300 instrument. ICP-MS measurements were carried out using a NexION 300X instrument.

[0231] Example 1 : Process for the recovery of Li, Co and Ni.

[0232] A particular example of the process of recovery of Li, Co, Ni from black mass according to the invention and shown in figure 1 consists of the following units: a) Black mass washing; b) First leaching step; c) Adjustment to pH 4; d) Co-selective liquid extraction and optional Li vs. Ni purification; e) Second leaching step; f) Adjustment to pH 6; g) Ni + Co solvent liquid extraction. Step a). In a_vessel, 1 kg of black mass, previously grounded as mentioned above, were contacted with tap water at a temperature comprised between 20-25 °C during a residence time of 1 hour.

[0233] Two output streams were recovered from the reactor: a liquid stream (A), rich in lithium and free of impurities, that can be used to generate a lithium product with commercial use in CAM manufacturing, and a solid stream of washed black mass (A’) comprising the remaining lithium and nearly all the Ni and Co present in the black mass.

[0234] The results of the washing step in terms of solubilization of the metals of interest and other metal impurities after the washing of the black mass and characterization of the output streams are summarized in the table 2 below.

[0235] Table 2

[0236] Step b). In this stage, the solid generated in the previous stage (i.e. washed black mass) rich in Li, Ni and Co was fed to the leaching area (Leach 1).

[0237] In practice, 0.9 kg of said washed black mass (with a real density of 200 g / L of water) were added as leaching feedstock to the leaching area (Leach 1). The leaching of the solid raw material was conducted through a series of reactors disposed in cascade arrangement. Each leaching reactor was provided with a stirrer. The leaching area (Leach 1) was also fed at the same time with an aqueous solution of HC1 in a weight proportion of 300 g of HCl / Kg of washed BM fed to leaching area).

[0238] The average leaching pH in the reactors was maintained at a value of 0.5-1.0, whereas the temperature was set at a constant value of about 30°C during 2 hours.

[0239] The objective of this step was to leach all the Li present in the input solid (A’). At this stage, in addition to Li, a portion of Ni and Co was inevitably leached. Thus, two output streams were recovered: a solid residue stream (B’) enriched in Ni and Co, and a liquid stream (B) enriched with Li, Ni and Co.

[0240] The results relative to leaching of the metals of interest at this stage are summarized in table 3 below).

[0241] Table 3

[0242] Step c). The liquid stream (B) generated in the first leaching step b) had an acid pH and it was adjusted by adding a ISfeCCh, so that the average pH was set at a value of 4. The temperature was kept at a maximum of 30°C. The time required to precipitate some of the critical impurities that come along with the liquid stream (B) was 2 h. The output streams of this stage were: a solid stream consisting of a hydroxide / carbonate mixture of Al and Fe, and an aqueous liquid stream (C) enriched in Li, Ni and Co.

[0243] The results relative to the metals of interest and other metal impurities after pH adjustment by characterization of the outlet liquid stream were the following:

[0244] Table 4. n.d: not determined. Step d). In this step, the liquid stream (C) generated in the previous stage was treated in two extraction stages within mixer vessels. Within each mixer vessel, the organic extractant (Cyanex 572® at 30% and dissolved in kerosene) and the aqueous liquid stream (C) in a ratio of 1 : 1 were thoroughly mixed to promote mass transfer and achieve chemical equilibrium. The pH during extraction is maintained at a value of 4 by adding NaOH (50- 200 g / L). The mixed phases then passed to the associated settler where they disengaged and flew away as separate streams. This hydro-dynamic process was identical in every mixer-settler within the solvent extraction area.

[0245] The output streams of this stage were: an organic liquid stream (D) containing cobalt that was further purified, and an aqueous liquid (D’) enriched in Li and Ni, with impurities of Al and Fe, which may be further purified by precipitation and / or selective extraction techniques with solvents.

[0246] Particularly, the separation of Li from Ni from the aqueous stream (D’) can be performed according to techniques known to the skilled person, based on the different physicochemical properties of the two metals. For example,

[0247] - by adjusting the pH of the aqueous solution to 8 with an hydroxide, nickel is recovered in the form of solid hydroxide, while lithium remains in the precipitation liquor; or

[0248] - by extraction with Cyanex 572 and adjusting pH to 6, nickel can be selectively separated.

[0249] The results relative to step d) are summarized in the following table 5.

[0250] Table 5. Once the cobalt is extracted to the organic phase, said cobalt-loaded organic phase (D) was led to a stripping unit. The organic phase (D) was counter-currently contacted with an aqueous solution of H2SO4 at a concentration of 88 g / L in a ratio of organic phase / aqueous phase of 4 / 1. The stripping was conducted twice. The net result of the stripping unit was the selective transfer of cobalt from the cobalt-loaded organic phase (D) to the aqueous solution, which becomes a cobalt-loaded aqueous solution, while the impurities such as iron and aluminium remained in the organic phase.

[0251] Step e). At this stage, the solid (B’) generated in step c), which is rich in Ni and Co, was fed to the leaching area (Leach 2).

[0252] In practice, 0.70 kg of the solid (B’) (with a density of 200 g / L of water) were added as leaching feedstock to the second leaching area. The leaching of the solid material (B’) was conducted in a reactor provided with a stirrer. The leaching area was also fed at the same time with an aqueous solution of HC1 in a weight proportion of 800 g of HCl / Kg of solid (B’) and with NaClO in a weight proportion of 500 g / kg solid (B’) fed.

[0253] The average leaching pH in the reactors was maintained at a value of 0.2-0.5, whereas the temperature was set at a constant value of about 40°C during 2 hours.

[0254] The objective of this step was to leach all the Co and Ni present in the input solid (B’). Thus, two output streams were recovered: a solid residue stream (E’) enriched in graphite present in the BM, and a liquid stream (E) enriched with Ni and Co.

[0255] The results relative to this second leaching step of the metals of interest at this stage are summarized in the table 6 below.

[0256] Table 6.

[0257] Step f).

[0258] The liquid stream (E) generated in the second leaching step e) had an acidic pH and it was adjusted by adding a Na2COs, so that the average pH was set at a value of 6. The temperature was kept at a maximum of 40°C. The time required to precipitate some of the critical impurities that come along with the liquid stream (E) was 2 h.

[0259] The output streams of this stage were: a solid stream (F’) consisting of a Cu hydroxide / carbonate mixture along with Al, Fe and some Co and Ni; and a liquid stream (F) enriched in Ni and Co that can be optionally fed to a Ni and Co extraction stage with solvent(s).

[0260] The results relative to the metals of interest are summarized in table 7 below (; n.d.: not determined).

[0261] Table 7

[0262] Step g). In this unit, the liquor at pH 6 generated in step f) is brought into contact with an organic solvent (Cyanex 572®) in order to selectively extract the nickel and cobalt present in the input solution into the organic phase while the remaining impurities stay in the aqueous raffinate.

[0263] In this step, the liquid stream (F) generated in the previous stage was treated in 3-5 extraction stages within mixer vessels. Within each mixer vessel, the organic extractant (Cyanex 572® at 30% and dissolved in kerosene) and the aqueous liquid stream (F) in a ratio of 1 were thoroughly mixed to promote mass transfer and achieve chemical equilibrium. The pH during extraction is maintained at a value of 6 by adding NaOH (50- 200 g / L) and the temperature was kept at 30°C. The mixed phases then passed to the associated settler where they disengaged and flew away as separate streams. This hydrodynamic process was identical in every mixer-settler within the solvent extraction area.

[0264] The output streams of this stage were: a nickel- and cobalt-loaded organic liquid stream (G) that may subsequently be used to generate a nickel-cobalt sulfate product for commercial use in CAM manufacturing, and an acidic aqueous liquid stream (G’) that may be recirculated to the process.

[0265] The extraction results of the metals of interest at this stage are summarized in table 8 below.

[0266] Table 8.

[0267] Once the nickel and cobalt was extracted to the organic phase, said nickel- and cobalt- loaded organic phase (G) was led to a stripping unit. The organic phase (G) was counter- currently contacted with an aqueous solution of H2SO4 at a concentration of 136 g / L in a ratio of organic phase / aqueous phase of 4 / 1. The stripping was conducted three times. The net result of the stripping unit was the selective transfer of cobalt and nickel from the organic phase (G) to the aqueous solution, which becomes a nickel- and cobalt-loaded aqueous solution (STI), while most of the impurities such as iron and aluminium remained in the organic phase (ST2).

[0268] Example 2: Process for the recovery of Li, Co and Ni with alternative washing step.

[0269] Example 1 above was repeated but the washing step a) of the black mass was carried by contacting said black mass with an aqueous solution containing methyl isobutyl carbinol (MIBC) and AERO 827 as flotation agents (see figure 3).

[0270] Aero827 was purchased from Syensqo and MIBC from Sigma Aldrich

[0271] The amounts of flotation agents were the following:

[0272] MIBC: 350 g per ton of dried BM

[0273] Aero 827: 500 g per ton of dried BM

[0274] Pulp density: 12,5 wt%

[0275] By means of this washing step, about 90% of the graphite present in the black mas was removed.

Claims

1. CLAIMS1.- A process for recovering Li, Ni and Co from black mass, said process comprising the steps of: a) contacting black mass with an aqueous solution to obtain an aqueous solution (A) comprising at least 30 wt.% of the starting Li present in the black mass and a solid residue (A’); b) leaching the solid (A’) with an acid aqueous solution of an inorganic acid having a pH between 0 and 3, to obtain a leached aqueous solution (B), comprising Li, Ni and Co, and a non-leached solid residue (B’) comprising the remaining Ni and Co; c) adjusting the pH of the aqueous solution (B) in the range 3.5 - 6.5, to obtain an aqueous solution (C) comprising Li, Ni and Co and a solid residue (C’); d) extracting Co from the aqueous solution (C) with at least one Co-selective organic extractant, to obtain an organic phase (D) comprising Co and an aqueous phase (D’) comprising Li and Ni, said Li and Ni being optionally further separated by selective precipitation and / or extraction; e) leaching the solid residue (B’) obtained in step b) by contacting it with a mixture comprising an aqueous solution of an inorganic acid and an oxidizing agent at a temperature between 25 and 60°C, to obtain an aqueous solution (E) and a solid residue (E’), wherein the aqueous solution (E) comprises Ni and Co and wherein the solid residue (E’) may comprise Co; f) adjusting the pH of the aqueous solution (E) in the range 4.5 - 6.5 to obtain an aqueous solution (F) and a solid residue (F’); g) extracting the aqueous solution (F) with at least one Ni-and Co-selective organic solvent to obtain an organic phase (G) comprising Ni and Co, and an aqueous phase (G’); and, optionally: h) when the solid residue (E’) comprises Co, leaching said solid residue (E’) with at least an aqueous solution of an inorganic acid to obtain an aqueous solution (H) comprising Co and a solid residue (H’); i) adjusting the pH of the aqueous solution (H) in the range 2.5 - 6.0 to obtain an aqueous solution (I) and a solid residue (F); and j) extracting the aqueous solution (I) with at least one Co-selective organic extractant to obtain an organic phase (J) comprising Co and an aqueous phase (J’).2.- The process according to claim 1, wherein in step a) the aqueous solution is water or the aqueous solution further comprises flotation reagents.3.- The process according to claim 1 or 2, wherein the inorganic acid in steps b) and e) is selected from hydrochloric acid, sulphuric acid, and nitric acid.4.- The process according to any one of claims 1 to 3, wherein in step c) the pH is adjusted to about 4.5.- The process according to any one of the preceding claims, wherein in step e) the inorganic acid is selected from hydrochloric acid, sulphuric acid, and nitric acid and the oxidizing agent is characterized by a standard reduction potential E° greater than +0.96 V.6.- The process according to any one of the preceding claims, wherein the organic extractant in steps d), g) and j) is selected from phosphoric acids and mixtures of alkyl phosphonic acids and alkyl phosphinic acids.7.- The process according to any one of the preceding claims, wherein in step f) the pH is adjusted to about 6.8.- The process according to any one of the preceding claims, wherein the adjustment of the pH in steps c), f) and i) is made by adding an aqueous solution of an inorganic base selected from an alkali metal carbonate and an alkali metal hydroxide.

9. The process according to any one of the preceding claims, further comprising stripping the cobalt- and nickel-loaded in any of the organic phases (D, G, J) with an acid aqueous solution, thus obtaining an acid aqueous solution containing cobalt and nickel and an organic stream containing metallic impurities.

10. The process according to any one of the preceding claims, wherein lithium and nickel contained in the aqueous phase (D’) are separated from each other by selective precipitation and / or extraction.

11. The process according to any one of the preceding claims, further comprising stripping the nickel- and cobalt-loaded in the organic phase (G) with an acid aqueous solution, thus obtaining an acid aqueous solution containing cobalt and nickel and an organic stream containing metallic impurities.12.- The process according to any one of the preceding claims, wherein the black mass is obtained from the battery of E-vehicles.

13. The process according to any one of the preceding claims, further comprising the purification and / or isolation of- the lithium from aqueous phase (A); and / or- the lithium and nickel from aqueous phase (D’); and / or- the nickel and cobalt from organic phase (G); and / or- the cobalt from organic phase (J), as Li, Ni and / or Co salts.14.- A process for making cathode active materials comprising the step of recovery of Li, Ni and / or Co according to the process of any one of claims 1 to 13 and further comprising the incorporation of the recovered Li, Ni and / or Co into cathode active materials.

15. Use of the Li, Ni and / or Co obtainable by a process as defined in any one of claims 1-13 to manufacture a cathode active material (CAM).

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