A method for critical materials recovery from li-ion batteries black mass

Abstract

The present invention relates to a method for recovering one or more valuable components from Li-ions batteries black mass, via one or more leaching, precipitation and filtration steps. An object of the present invention is to provide a method for recovering one or more valuable components from Li-ions batteries black mass and to recover raw materials that can be re-used as a new pre-cursor cathode active material.

Description

[0001] Title: A method for critical materials recovery from Li-ion batteries black mass.

[0002] Description:

[0003] The present invention relates to a method for recovering one or more valuable components from Li-ions batteries black mass, via one or more leaching, precipitation and filtration steps.

[0004] Lithium-ion batteries are increasingly used in essential application for energy storage. These include e.g. energy storage for powering electric vehicles, bikes, laptops, telephones, cameras, tools and equipment. Lithium-ion batteries contain a variety valuable metals and materials, also indicated as critical or strategic raw materials. With the rising amount of end-of-life lithium-ion batteries, as well as production scrap from lithium-ion battery manufacturers, the recovery of these valuable materials has become a very important industry. Urban mining and recycling of the batteries provides local sources of raw materials and preserves our natural resources.

[0005] Conventional recycling methods do not adequately handle the recycling of different types and varieties of cathode chemistries, do not sufficiently extract critical raw materials, maintaining high functionality and performance levels of materials, also minimizing emissions and residues. Typically, large battery packs are dismantled up to a size of small modules or to cells. Small modules or cells can also be integrated as part of an electronic device or equipment. Small modules, cells, or devices are usually crushed or shredded followed by physical separation to obtain a powder that is normally referred to as black mass and has a valuable content.

[0006] Several recycling methods and processes are known for the recovery of metals from black mass, which are currently operated on different scales, from laboratory to industrial scale.

[0007] The pyrometallurgical route is used on industrial scale and that concerns the recovery of valuable metals, such as Co, Ni that are fully recovered in the form of alloy at high temperature. Organic materials are combusted and lost, as well as other valuable metals such as lithium and manganese, which end-up in the slag or in the flue dust. Other processes use the conventional hydrometallurgical route in which the black mass is leached with sulfuric acid (usually supported by hydrogen peroxide as an additive) to dissolve metals in solution. The foregoing step consists of solution purification and precipitation of metal oxides, see for example US Pat. No. 1015017B2; US Pat. No. 11339481 B1 ; US Pat. No. 10522884B2; CN Pat. No. 103346365B; CN Pat. No. 1953269A; US Pat. No 9834827B2; US Pat. No 10919046B2; US Pat. No 11876196B2; US Pat. No. 2021 / 0032721 A1.

[0008] Several hydrometallurgical processes have been developed during the last decades, but none of these technologies have been implemented in large commercial scale; most of these technologies remain in laboratory or pilot plant scale. Therefore, there is important for designing and further implementing a commercial metals recovery plant from black mass.

[0009] US 2023 / 246259 relates to a process for separating a mixture of oxalates of two or more of nickel (Ni), cobalt (Co), and manganese (Mn), comprising the steps of dissolving the mixture of oxalates in an acid to form a solution having a pH of -0.5 or less, precipitating nickel oxalate, cobalt oxalate and / or manganese oxalate by adding a base and separating the precipitated metal oxalate from the remaining solution of step (c) by a solid, a liquid, or a solid and liquid separation. According to this US patent oxalic acid is used as a precipitation agent in purification leading to separate Ni, Co and Mn as a mixture of Ni, Co and Mn oxalates. The process steps according to this US patent include, inter alia, calcination leading to high CO2 emissions.

[0010] A scientific article written by Neumann Jonas et al: "Recycling of Lithium-Ion Batteries Current State of the Art, Circular Economy, and Next Generation Recycling", ADVANCED ENERGY MATERIALS, vol, nr. 17, 10 May 2022 (2022-05-10), discloses in Figure 4 thereof a traditional hydrometallurgical processing of black mass collected from batteries. A hydrometallurgical treatment is used after smelting of the batteries to recover metals from the alloy, i.e. matte. Matte processing starts with comminution followed by pressure oxidation leaching at 6 to 8 bar. Afterward, impurities are removed prior to solvent extraction of Cu, Co, and Ni. Before extraction, Fe is precipitated as goethite (FeOOH) by using H2O2 as an oxidizing agent and basic nickel carbonate for pH adjustment. Depending on the process setup, copper sulfate, cobalt sulfate, and nickel sulfate, or nickel carbonate and chloride are produced. The process shown here includes a specific pre-treatment, a one step leaching, solvent extraction for Ni, Co, Mn and Li extraction as a last step.

[0011] A scientific article written by Or Tyler et al: "Recycling of mixed cathode lithium- ion batteries for electric vehicles: Current status and future outlook", CARBON ENERGY, vol 2, nr. 1 , 10 January 2020 (2020-01-10), pages 6-43 discloses a hydrometallurgical process wherein following pretreatment to separate the cathode from other battery components, the active material is dissolved entirely by reductive acid leaching. A complex leachate is generated, comprising cathode metals (Li+, Ni2+, Mn2+, and Co2+) and impurities (Fe3+, Al3+, and Cu2+) from the current collectors and battery casing, which can be separated and purified using a series of selective precipitation and / or solvent extraction steps. Alternatively, the cathode can be resynthesized directly from the leachate. This scientific article is totally silent about a two step leaching process and fails to teach a specific type of acid to be used for selective leaching.

[0012] A scientific article written by Botelho Junior Amilton et al: "Separation of Critical Metals by Membrane Technology under a Circular Economy Framework: A Review of the State-of-the-Art", PROCESSES, vol 11 , nr. 4, 19 April 2023 (2023-04-19), pages 1256-1279 relates to membrane applications to obtain critical metals — lithium (Li), cobalt (Co), and rare earth elements (scandium — Sc, yttrium — Y, lanthanum — La, and neodymium — Nd), i.e. to obtain critical metals from primary and secondary sources, acid mine drainage (AMD), industrial wastes, and the recycling of electronic wastes (e-wastes) and brine. This scientific article describes reverse osmosis in a general way for purification purposes in a sulfate solution after solvent extraction.

[0013] A scientific article written by Niu Bo et al: "Recycling Hazardous and Valuable Electrolyte in Spent Lithium-Ion Batteries: Urgency, Progress, Challenge, and Viable Approach", CHEMICAL REVIEWS, vol 123, nr. 13, 20 June 2023 (2023-06-20), pages 8718-8735 discloses several processes, e.g. destroying the structure of spent Lithium- ion batteries (LIBs) to separate and recover valuable components such as electrode materials, metal shells, electrolyte, and so on. The following approach is extracting valuable metals such as Li, Co, Mn, and Ni from spent LIBs by hydrometallurgy and pyrometallurgy, i.e. electrolyte recycling by mechanical processing, distillation, freezing, solvent extraction and supercritical carbon dioxide.

[0014] A scientific article written by Akhmetov Nikita et al: "Li-Ion Battery Cathode Recycling: An Emerging Response to Growing Metal Demand and Accumulating Battery Waste", ELECTRONICS, vol 12, nr. 5, 27 February 2023 (2023-02-27), pages 1152-1189 discloses various Lithium-ion batteries pretreatment techniques, such as manual dismantling, crushing and sieving, different cathode leaching methods, such as inorganic, organic acids, ammonia and bioleaching, and separation technologies, such as extraction and precipitation, electrochemical treatment, i.e. utilization of ionic liquids and deep eutectic solvents and direct cathode restoration technologies.

[0015] A scientific article written by Mohanty Archita et al: "A Review on Green Method of Extraction and Recovery of Energy Critical Element Cobalt from Spent Lithium-Ion Batteries (LIBs)", MINERAL PROCESSING AND EXTRACTIVE METALLURGY REVIEW, vol 44, nr. 1 , 21 October 2021 (2021-10-21), pages 52-6 discloses processes to recover cobalt from secondary sources (LIBs) with organic acids and cobalt recovery from primary resources and inorganic acids. The general hydrometallurgical route for the recycling of lithium-ion waste batteries starts with spent LIBs, i.e. steps of discharging, dismantling and separation resulting in plastic, Cu / AI foil, anode(graphite) and recycling / reusable products on the one hand, and cathode materials on the other hand. The cathode materials are further processed via pretreatment, acid leaching forming leachant and reductant, filtration forming residue and filtrate (pure metal solution) and purification, separation and resynthesize of cathode materials. This scientific article discloses a two step leaching process by using oxalic acid in a first step and sulfuric acid and H2O2 in a second step.

[0016] A scientific article written by Rumsby Paul et al: "Speciation of manganese in drinking water", Toxicology Letters, 1 March 2014 (2014-03-01), pages 1-134 discloses the potential neurotoxicity of Mn relating to oral intake via drinking water, both in experimental animals and humans, including the bioavailability of different states of Mn. This scientific article discloses a step of extracting Mn by selective precipitation involving additives and / or different pH.

[0017] An object of the present invention is to provide a method for recovering one or more valuable components from Li-ions batteries black mass and to recover raw materials that can be re-used as a new pre-cursor cathode active material.

[0018] Another object of the present invention is to provide a method for recovering one or more valuable components from Li-ions batteries black mass wherein direct CO2 emissions are zero, compared to pyrometallurgical processes wherein direct CO2 emissions are significant.

[0019] Another object of the present invention is to provide a method for recovering one or more valuable components from Li-ions batteries black mass wherein a stream comprising NaCI is produced as valuable product stream. The present invention thus relates to method for recovering one or more valuable components from Li-ions batteries black mass, via one or more leaching, precipitation and filtration steps, wherein the method comprises the following: a) Providing Li-ions batteries black mass, b) Leaching the black mass of a) with an acid thereby forming a liquid phase comprising soluble complex compounds of Al and Li and a solid phase comprising insoluble compounds of one or more of graphite, Fe, Cu, Ni, Co and Mn, c) Concentrating the liquid phase of b) via a membrane technique thereby forming a concentrated liquid phase and a permeate liquid phase, d) Precipitating Al compounds from the concentrated liquid phase of c), e) Precipitating Li compounds from the liquid phase obtained after d).

[0020] The present inventors found that on basis of such a process one or more of the above mentioned objects can be achieved. Technical features of the present invention include a two-stage leaching of black mass under the use of acid subsequently hydrochloric acid medium, internal redox, separation of metals by one or more of selective precipitation and ion-exchange. The valuable metals are preferably recovered as carbonates or hydroxides. The effluents and emissions are controlled and may be recycled or converted to reagent products. The present inventors also found that by using of a chloride medium a stream comprising NaCI is produced as a final product instead of Na2SO4 or CaSC that are produced by sulphate medium commonly used in the industry, wherein sulfates compounds have high disposal costs compared to NaCI.

[0021] The term black mass as a feedstock material in the present method for recovering one or more valuable components refers to materials obtained after shredding and physical separation of spent lithium-ion batteries, lithium battery waste, lithium ion battery production scrap, lithium ion cell production scrap, lithium ion cathode active material. The active components of the electrodes such as graphite and may include impurities from casing, electrode foils, cables, separator, and electrolyte.

[0022] The composition of black mass consists of various components related to the design of the battery and chemistry of the cell, i.e. lithium cobalt oxide (LCO), lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium manganese oxide (LMO), lithium nickel cobalt aluminium (NCA), and can be a mix of different elements and different ratios.

[0023] A typical black mass of a NMC Li-ion battery (cathode active material is LiNixMnyCO(i.x-y)O2) may comprise a system of Li (3-4%), Co (3-20%), Ni (5-20%), Cu (0.2-6%), Mn (3-10%), Fe (0.02-6%), Al (0.5-6%) and C (25-50%) and traces of other elements. From this system to achieve the objectives of the recovery of Li, Ni, Co, Cu and Mn, the present method may comprise the following steps: removal and recovery of lithium, iron removal that will improve the purity of Ni, Co, Cu and Mn, and Ni and Co separation or coprecipitation.

[0024] In an example the present method for recovering one or more valuable components from Li-ions batteries black mass further comprises one or more of the following steps: f) Leaching the solid phase of b) with an acid thereby forming a liquid phase comprising soluble compounds of one or more of Fe, Cu, Ni, Co and Mn and a solid phase comprising graphite, g) Precipitating Fe from the liquid phase of f), h) Precipitating Cu from the phase obtained after g), i) Precipitating Ni and Co from the phase obtained after h), j) Precipitating Mn from the phase obtained after i).

[0025] In an example the present method for recovering one or more valuable components from Li-ions batteries black mass further comprises processing of the phase obtained after j) for obtaining an aqueous stream to be returned to one or more of the aforementioned steps b)-j).

[0026] In an example the present method for recovering one or more valuable components from Li-ions batteries black mass further comprises processing of the phase obtained after j) for recovering one or more of NaCI, NaOH and HCI.

[0027] In an example the acid of step b) is chosen from one or more of the group of oxalic acid, glycine and ethylenediaminetetraacetic acid (EDTA), or a combination thereof, preferably oxalic acid.

[0028] In an example step b) is carried out at a temperature in a range of at least 30°C, preferably at least 50 °C and at most 90 °C, preferably at most 70 °C, during a residence time of at least 30 min, preferably at least 90 min.

[0029] In an example step d) is carried out by contacting the concentrated liquid phase of c) with NaOH and / or Na2COs thereby forming a precipitate of Al. In an example step e) is carried out by contacting the liquid phase obtained after d) with a lye solution thereby forming a precipitate of Li, wherein the lye solution is alkaline, preferably NaOH or Na2COs.

[0030] In an example step g) is carried by contacting the liquid phase of f) with a lye solution in a first sub step and with a hypochlorite solution in a second sub step, thereby forming a precipitate of Fe.

[0031] In an example step h) is carried by contacting the phase obtained after g) with a lye solution, thereby forming a precipitate of Cu.

[0032] In an example step i) is carried out by a method chosen from the group of a method comprising a first sub step of a precipitation of Ni and a second sub step of a precipitation of Co, a method comprising a first sub step of a precipitation of Co and a second sub step of a precipitation of Ni, and a method comprising a co-precipitation of both Co and Ni.

[0033] In an example the liquid phase rich in Co obtained after h) is subjected to a first sub step of a precipitation of Ni and a second sub step of a precipitation of Co, thereby forming a precipitate of NiS and Co(OH)2

[0034] In an example the liquid phase rich in Ni obtained after h) is subjected to a first sub step of a precipitation of Co and a second sub step of a precipitation of Ni, thereby forming a precipitate of Co(OH)2 and Ni(OH)2.

[0035] In an example the liquid phase having about equal amounts of Co and Ni obtained after h) is subjected to ion exchange, thereby forming a precipitate of Co(OH)s and Ni(OH)2.

[0036] In an example step j) is carried out by contacting the phase obtained after i) with a lye solution, thereby forming a precipitate of Mn(OH)2.

[0037] In an example processing of the phase obtained after j) is carried out by one or more process steps chosen from the group of reverse osmosis, crystallization, ion exchange and activated carbon, or a combination thereof.

[0038] In an example the present method for recovering one or more valuable components from Li-ions batteries black mass further comprises a step of filtering the solid phase comprising graphite of step d) thereby obtaining graphite.

[0039] In an example the present method for recovering one or more valuable components from Li-ions batteries black mass further comprises a step of recovering carbon dioxide and chlorine gas from step f) and converting the carbon dioxide into sodium carbonate and chlorine gas into sodium hypochlorite.

[0040] In an example the sodium carbonate is used in step e) of precipitating Li from the liquid phase, sodium hypochlorite is used in step g) of precipitating Fe from the liquid phase of f).

[0041] The drawing schematically illustrate an example of a method according to the present invention. The present method is not restricted to the specific example disclosed here.

[0042] The sole Figure discloses a schematic process flow diagram of a method according to the present invention.

[0043] According to the sole Figure Black Mass 18 is subjected to a leaching step 1 with an acid (not shown here) thereby forming a liquid phase 21 comprising soluble complex compounds of Al and Li and a solid phase 19 comprising insoluble compounds of one or more of graphite, Fe, Cu, Ni, Co and Mn. The acid is chosen from one or more of the group of oxalic acid, glycine and ethylenediaminetetraacetic acid (EDTA), or a combination thereof, preferably oxalic acid.

[0044] Liquid phase 21 is concentrated via a membrane technique 2 thereby forming a concentrated liquid phase 22 and a permeate liquid phase 25. Step 3 is a neutralization and precipitation step wherein NaOH is added and Al compounds 24 from the concentrated liquid phase 22 are precipitated. Liquid phase 23 obtained after precipitation step 3 is subjected to further neutralization and precipitation step 4 by addition of NaOH and / or Na2COs thereby forming a precipitate 9 of Li compounds.

[0045] Solid phase 19 is subjected to an oxidative leaching step 5 with an acid (not shown here) thereby forming a liquid phase 26 comprising soluble compounds of one or more of Fe, Cu, Ni, Co and Mn, and a solid phase 20 comprising graphite.

[0046] Liquid phase 26 is subjected to a precipitation step 6 with the addition of NaOCI (not shown here) and a lye solution (not shown here) for obtaining a precipitate 27 of Fe from liquid phase 26. The remaining liquid phase 28 is subjected to a precipitation step 7 with the addition of a lye solution (not shown here) for obtaining a precipitate 29 of Cu compound from liquid phase 28. Liquid phase 30 is subsequently subjected to step 8 for recovering of critical materials. After recovering Ni / Co, identified as stream 31 , a liquid phase 42 comprising Mn is obtained. Liquid phase 31 can be further processed via three different routes dependent on composition of liquid phase 31 , namely the ratio Ni and Co, i.e. a liquid stream 32, a liquid stream 36 and a liquid stream 47.

[0047] According to a situation wherein stream 32 is rich in Co, stream 32 is subjected to a first sub precipitation step 10 by addition of NaHS resulting in a precipitate 33 of NiS and a second sub step 11 of a neutralization with NaOH and precipitation of a precipitate 35 of Co.

[0048] According to a situation wherein stream 36 is rich in Ni, stream 36 is subjected to a first sub step 13 of an acidification by adding HCI and oxidation by adding sodium hypochlorite and precipitation of a precipitate 37 of Co and a second sub step 14 of neutralization by NaOH and precipitation of a precipitate 39 of Ni.

[0049] According to a situation wherein stream 47 is about equal in Co and Ni, stream 47 can be directly separated in step 15 comprising ion exchange into a precipitate 40 of Ni and a precipitate 41 of Co.

[0050] Liquid phase 42 comprising Mn is subjected to a neutralization by adding NaOH and precipitation step 16 for obtaining a precipitate 43 of Mn. The remaining liquid phase 44 comprising NaCI is further treated in step 17 thereby forming an aqueous stream 45 and a stream 46 which is a concentrated brine or solid salt of NaCI.

[0051] The above discussed steps will now be discussed into detail for illustrated purposes only.

[0052] Black mass is contacted with oxalic acid in the range of 1 % to 6% during 60 minutes at temperature of 50°C, pulp density of 20% in a stirred tank reactor, where more than 95% of lithium and aluminum are leached. The reactor content is pumped to a filter to separate the liquid stream and the solid stream. The solid residues are subjected to hydrochloric acid leaching. The dissolution of metals by oxalic acid is acid / complex based, wherein the metal oxides are solved into the solution. The ion oxalates, i.e. strong chelating agents, react with the metal ions forming metal oxalate complexes. Thus, lithium reacts with oxalate ion to form a simple oxalate that is soluble. While Cu, Co, Mn, Ni to remain as oxides or form simple and complex oxalates that have low solubility. Aluminum on the other hand is reported to form only complex oxalate compounds which are soluble in aqueous media.

[0053] The removal of lithium as a first stage leaching increases the recovery rate compared to other processes where lithium is to be removed in the end. The present inventors found that solely the first leaching step is suitable for the black mass from LFP batteries. The liquid phase containing Li and Al will be contacted with NaOH to precipitate Al as AI(OH)s, after lithium is recovered as Li(OH) or Li2COs.

[0054] After oxalic acid leaching and filtration the solid residue, i.e. metals, oxalates, oxides, or a mix, is treated in a stirring tank reactor with hydrochloric acid during 60 minutes at a temperature range of 25-90°C (3) and a pulp density of 20%. More than 99% of metals are leached. The oxidative leach of the solid residue with hydrochloric acids results to CI2 and CO2 formation that may be converted to NaOCI and Na2COs. After hydrochloric acid leaching the reactor content is pumped through a filter to separate solid residue subject to disposal. The filtrate is subjected to purification operation by selective precipitation.

[0055] The removal of iron can be carried out as a two steps process, wherein NaOCI is added in order to oxidize any Fe2+to Fe3+, and Fe3+is reacted with NaOH to precipitate as ferric hydroxide, a process known as goethite process. These reactions take place at ambient temperature, pH equal to about 2 for the oxidation and pH range about 2 to 4.5 for the precipitation reaction. After filtration the pregnant solution is subjected to Cu removal.

[0056] NaOH is injected into the pregnant solution to reach a pH range of about 5 to 6.5 where Cu(OH)2 precipitates. The content of stirring reactor is pumped through a filter to separate copper hydroxide to a filtrate.

[0057] After copper recovery, the pregnant solution contains Ni, Co and Mn. Therefore, three situations are considered according to the Ni / Co ratio, i.e. a cobalt rich solution, a nickel rich solution and a somewhat equal ratio Ni / Co.

[0058] For a cobalt rich solution, prior to cobalt recovery, nickel is removed as a precipitate. Therefore, the pH is adjusted to about a pH of 6.5 in a stirring reactor and Ni reacts with NaHS to precipitate as nickel sulfide NiS. After nickel removal the reactor content is pumped through a filter. The pH will be adjusted to a pH range of about 7.5 to 8.5 and cobalt precipitates as Co(OH)2.

[0059] In a situation of a nickel rich solution, prior to nickel recovery, cobalt is removed from solution in three operations; pH is adjusted to about 2.5 with 15% HCI acid injection, oxidation of Co2+to Co3+with a solution of NaOCI and precipitation of Co3+as Co(OH)s. After filtration and neutralization with 10% NaOH to a pH of about 6-7 nickel is recovered as Ni(OH)2. In a situation of a solution with Ni / Co ratio around 1 , nickel and cobalt can be separated by ion exchange, preferably nickel is removed by ion exchange and a nickel eluate will be subjected to nickel precipitation. Subsequently cobalt hydroxide will be precipitated.

[0060] After removal of both nickel and cobalt a lye solution of NaOH is injected into the remaining solution leading to pH of about 9-9.5 in a stirring tank reactor where manganese ions precipitate as Mn(OH)2. After manganese precipitation, the reactor content is pumped through a filter to separate the precipitate and the Barren solution.

[0061] The Barren solution with pH of up to 10 will be processed to obtain water to be re-used within the process and purified NaCI. NaCI can be sold as a high valuable product and can for example be used in an electrolysis process for the production of CI2 with by-products NaOH and HCI thereby closing the reagent cycle.

[0062] From the above description, the present method for recovering one or more valuable components from Li-ions batteries black mass is to be considered as a clean and closed process without the formation of any solid or liquid waste.

[0063] Effluent streams originating from filters in the present method for recovering one or more valuable components from Li-ions batteries black mass as used for precipitates washing and filters washing will contain anions and cations. These anions and cations can be removed by an ion exchange process for recovering anions and cations in the eluate stream, and the eluate can be internally recycled. Removal of organic compounds from an aqueous stream can be done by subjecting such stream to an activated carbon adsorption step.

Claims

CLAIMS1. A method for recovering one or more valuable components from Li-ions batteries black mass, via one or more leaching, precipitation and filtration steps, wherein the method comprises the following: a) Providing Li-ions batteries black mass, b) Leaching the black mass of a) with an acid thereby forming a liquid phase comprising soluble complex compounds of Al and Li and a solid phase comprising insoluble compounds of one or more of graphite, Fe, Cu, Ni, Co and Mn, c) Concentrating the liquid phase of b) via a membrane technique thereby forming a concentrated liquid phase and a permeate liquid phase, d) Precipitating Al compounds from the concentrated liquid phase of c), e) Precipitating Li compounds from the liquid phase obtained after d).

2. A method according to claim 1 , further comprising one or more of the following steps: f) Leaching the solid phase of b) with an acid thereby forming a liquid phase comprising soluble compounds of one or more of Fe, Cu, Ni, Co and Mn, and a solid phase comprising graphite, g) Precipitating Fe from the liquid phase of f), h) Precipitating Cu from the phase obtained after g), i) Precipitating Ni and Co from the phase obtained after h), j) Precipitating Mn from the phase obtained after i).

3. A method according to any one or more of claims 1-2, further comprising processing of the phase obtained after j) for obtaining an aqueous stream to be returned to one or more of the aforementioned steps b)-j).

4. A method according to any one or more of claims 1-3, further comprising processing of the phase obtained after j) for recovering one or more of NaCI, NaOH and HCI.

5. A method according to any one or more of claims 1-4, wherein the acid of step b) is chosen from one or more of the group of oxalic acid, glycine and ethylenediaminetetraacetic acid (EDTA), or a combination thereof, preferably oxalic acid.

6. A method according to any one or more of the preceding claims, wherein step b) is carried out at a temperature in a range of at least 30°C, preferably at least 50 °C and at most 90 °C, preferably at most 70 °C, during a residence time of at least 30 min, preferably at least 90 min.

7. A method according to any one or more of the preceding claims, wherein step d) is carried out by contacting the concentrated liquid phase of c) with NaOH and / or Na2CC>3 thereby forming a precipitate of Al.

8. A method according to any one or more of the preceding claims, wherein step e) is carried out by contacting the liquid phase obtained after d) with a lye solution thereby forming a precipitate of Li, wherein the lye solution is alkaline, preferably NaOH or Na2COs.

9. A method according to any one or more of claims 2-8, wherein step g) is carried by contacting the liquid phase of f) with a lye solution in a first sub step and with a hypochlorite solution in a second sub step, thereby forming a precipitate of Fe.

10. A method according to any one or more of claims 2-9, wherein step h) is carried by contacting the phase obtained after g) with a lye solution, thereby forming a precipitate of Cu.

11. A method according to any one or more of claims 2-9, wherein step i) is carried out by a method chosen from the group of a method comprising a first sub step of a precipitation of Ni and a second sub step of a precipitation of Co, a method comprising a first sub step of a precipitation of Co and a second sub step of a precipitation of Ni, and a method comprising a co-precipitation of both Co and Ni.

12. A method according to claim 11 , wherein the liquid phase rich in Co obtained after h) is subjected to a first sub step of a precipitation of Ni and a second sub step of a precipitation of Co, thereby forming a precipitate of NiS and Co(OH)213. A method according to claim 11 , wherein the liquid phase rich in Ni obtained after h) is subjected to a first sub step of a precipitation of Co and a second sub step of a precipitation of Ni, thereby forming a precipitate of Co(OH)s and Ni(OH)2.

14. A method according to claim 11 , wherein the liquid phase having about equal amounts of Co and Ni obtained after h) is subjected to ion exchange, thereby forming a precipitate of Co(OH)2 and Ni(OH)2.

15. A method according to any one or more of claims 2-14, wherein step j) is carried out by contacting the phase obtained after i) with a lye solution, thereby forming a precipitate of Mn(OH)2.

16. A method according to any one or more of claims 2-15, wherein processing of the phase obtained after j) is carried out by one or more process steps chosen from the group of reverse osmosis, crystallization, ion exchange and activated carbon, or a combination thereof.

17. A method according to any one or more of the preceding claims, further comprising a step of filtering the solid phase comprising graphite of step d) thereby obtaining graphite.

18. A method according to any one or more of claims 2-17, further comprising a step of recovering acidic gas from step f) and converting said acidic gas into sodium hypochlorite.

19. A method according to claim 18, wherein said sodium hypochlorite is used in step g) of precipitating Fe from the liquid phase of f).

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