Continuous process and production plant for preparing acidic aqueous metal solutions

Abstract

The present disclosure relates to a continuous process and a production plant for preparing an acidic aqueous solution comprising nickel, cobalt, manganese, and lithium cations.

Description

[0001] BASF SE B25.133P-WO67056 Ludwigshafen am Rhein 19.12.2024 / lg / np / jlContinuous process and production plant for preparing acidic aqueous metal solutions The project leading to this application has received funding from Bundesministerium für Wirtschaft und Klimaschutz and State of Brandenburg (DE; FKZ:16BZF101A / B); the applicant bears responsibility for all disclosures herein. Field of the invention The present disclosure relates to a continuous process and a production plant for preparing an acidic aqueous solution comprising nickel, cobalt, manganese, and lithium cations. Background Lithium ion battery materials are complex mixtures of various elements and compounds. For example, many lithium ion battery materials contain valuable metals such as lithium, aluminum, copper, nickel, cobalt, and / or manganese. It may be desirable to recover various elements and compounds from lithium ion battery materials. For example, it may be advantageous to recover lithium, aluminum, copper, nickel, cobalt, and / or manganese. Accordingly, there is a need for devices and processes for recycling lithium ion battery materials.WO 2023 / 054621 A1 discloses a method for recovering valuable metals fromwaste lithium ion batteries comprising a dissolution step for dissolving an active material powder obtained by pre-treating the waste lithium-ion batteries in a mineral acid to obtain an acid solution; and a solvent extraction step for separating manganese, cobalt, and nickel, among metals contained in the active material powder, from the acid solution through solvent extraction to obtain a first lithium salt aqueous solution as a residual liquid of the solvent extraction.WO 2020 / 124130 A1 discloses a method for the recovery of metals from afeed stream containing one or more value metals and lithium. The method comprises subjecting the feed stream to a sulfuric acid leach to form a slurry comprising a pregnant leach solution of soluble metal salts and a solid residue; separating the pregnant leach solution and the solid residue; subjecting the pregnant leach solution to one or more separate solvent extraction steps, wherein each solvent extraction step recovers one or more value metals from the pregnant leach solution, the remaining pregnant leach solution comprising lithium; and recovery of lithium from the pregnant leach solution.WO 2023 / 104830 A1 discloses methods for leaching a material comprisingone or more metals in a zero oxidation state and one or more chosen from metal oxides, metal hydroxides, and combinations thereof. The method comprises contacting the material with an oxidizing acidic aqueous solution having a pH less than 6, and subsequently reducing the one or more chosen from metal oxides, metal hydroxides, and combinations thereof with a reducing agent. Also disclosed are methods comprising leaching a material to obtain an aqueous solution comprising metal ions, and separating the metal ions to obtain at least one essentially pure metal ion solution and / or at least one essentially pure solid metal ion salt. Further disclosed are methods comprising mechanically comminuting a material to obtain a black mass, and leaching the black mass.WO 2022 / 167662 A1 discloses a process for producing a cathode materialprecursor having a desired active material target ratio for use in a lithium-ion secondary cell. The process comprises the steps: a) providing a leachate comprising one or more active materials selected from Ni, Co and Mn; b) identifying ionic impurities comprised in the leachate, and determining the concentration of each ionic impurity and of each active material in the leachate; c) adjusting the concentration of the one or more active materials in the leachate based on a total concentration of ions in the leachate; and d) raising the pH of the leachate to a level causing coprecipitation of the one or more active materials at a ratio corresponding to the desired active material target ratio for the precursor and causing coprecipitation of a minimum amount of ionic impurities, to obtain the cathode material precursor having the desired active material target ratio. It is an object of the present disclosure to provide an improved recycling plant for lithium ion battery materials and an improved recycling process for lithium ion battery materials. Summary of the invention The present disclosure provides a continuous process for preparing an acidic aqueous solution comprising nickel, cobalt, manganese, and lithium cations from various lithium ion battery materials, such as black mass (BM), cathodeactive materials (CAM), and mixed metal hydroxide precipitates (MHP).The process comprises a) leaching BM and / or CAM with sulfuric acid under inert atmosphere at a temperature of from 70°C to 95°C, for a time of from 0.5to 4 h, with an amount of acid ranging from 0.7 kg to 2 kg acid per kg BM and / orCAM. The mixture obtained in step a is subsequently b) leached with sulfuric acid while injecting air into the mixture, at a temperature of from 70°C to 90°C, for atime of from 2 to 5 h, at a pH of 2.5 or less, e.g., from -1.0 to 2.5, or from 0 to2.5, or from 0.5 to 2.5. Subsequently, c) MHP is added to the mixture obtained in step b).In some embodiments, the mixture obtained further is d) leached with sulfuricacid while adding a sulfur-containing reducing agent to the mixture, at atemperature of 70°C to 95°C, for a time of from 1 to 2 h, at a pH of 2.0 or less,e.g., from -1.0 to 2.0, or from 0 to 2.0, or of from 0.5 to 2.0. In some embodiments, e) MHP is added to the mixture in step d) to adjust the pH of the mixture to be in the range of from 1.5 to 2.5. Then, f) solids are removed from the mixture obtained after the last step in the sequence of steps b) through e). Subsequently, the pH of the solution obtained in step f) is g) adjusted to be in the range of from 1.5 to 2.5 by addition of sodium hydroxide and / or MHP, andcopper cations are removed from the solution by solvent extraction.The pH of the aqueous solution depleted of copper cations obtained in step g) ish) adjusted to be in the range of from 3.0 to 5.0 by addition of sodiumcarbonate, calcium carbonate, and / or MHP, and a precipitate which comprisesimpurity cations of the group consisting of Al and Fe and impurity anionscomprising P, F, Al, and / or Si present in the solution is generated.Finally, i) solids are removed from the mixture obtained in step h) to obtain theacidic aqueous solution comprising nickel, cobalt, manganese, and lithium cations. The present disclosure also provides a production plant suitable for performing the continuous process of the present disclosure. Brief description of the drawingsFig. 1 is a schematic diagram of an exemplary production plant of the presentdisclosure,Fig. 2 is a diagram showing copper dissolution velocity during oxidativeleaching at 85°C and at 90°C. Detailed descriptionThe present disclosure provides a continuous process for preparing an acidicaqueous solution comprising nickel, cobalt, manganese, and lithium ions. The process of the present disclosure can use various starting materials to produce the acidic aqueous solution comprising nickel, cobalt, manganese, and lithium ions. Examples include lithium ion battery materials, such as black mass(BM), cathode active materials (CAM), and mixed hydroxide precipitates (MHP).In the present disclosure, the term black mass (BM) means a particulatematerial having an average particle diameter (D50) in the range of from 1 μm to 500 μm, obtained by mechanical comminution of at least one battery material chosen from a lithium ion battery, lithium ion battery waste, lithium ion battery production scrap, lithium ion cell production scrap, lithium ion cathode active material, and combinations thereof, drying the comminuted battery material at a temperature below 200°C, and sifting the comminuted and dried battery material to obtain a fine fraction having an average particle diameter (D50) in the range of from 1 μm to 500 μm (oxidic black mass), or obtained by mechanical comminution of at least one battery material chosen from a lithium ion battery, lithium ion battery waste, lithium ion battery production scrap, lithium ion cell production scrap, lithium ion cathode active material, and combinations thereof, and subsequent heat treatment of the comminuted battery material at a temperature in the range of from 350°C to 900°C under an inert or reducing atmosphere and sifting to obtain a fine fraction having an average particle diameter (D50) in the range of from 1 μm to 500 μm (reducedblack mass). Black mass generally comprises from 0.1 to 10 wt.% Li, from 10 to50 wt.% Ni , from 0.1 to 20 wt.% Co, from 0.1 to 15 wt.% Mn, from 0 to 10 wt.%Cu, from 0 to 40 wt.% C, e.g., graphite, from 0 to 8 wt.% Al, and from 0 to 5wt.% F.In the present disclosure, the term cathode active material (CAM) means amaterial being present in a cathode of a lithium ion battery as the active component. The CAM may either be an off-spec material from CAM production, a material retrieved from an off-spec cathode, or a CAM material retrieved from a lithium ion battery. The CAM is either a layered oxide (such as lithium cobalt oxide) or a spinel (such as lithium manganese oxide). Examples of cathode active materials include lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), and lithium nickel manganese cobalt oxide (LiNiMnCoO2or NMC). In some embodiments, the material comprises one or more chosen fromlithiated nickel cobalt manganese oxide and lithiated nickel cobalt aluminumoxide. In some embodiments, the material comprises lithiated nickel cobalt manganese oxide of formula Li 1 1+x(NiaCobMncMd)1-xO2, wherein M1is chosen from Mg, Ca, Ba, Al, Ti, Zr, Zn, Mo, V and Fe, zero ≤ x ≤ 0.2, 0.1 ≤ a ≤ 0.95, zero ≤ b ≤ 0.9 (such as 0.05 < b ≤ 0.5), zero ≤ c ≤ 0.6, zero ≤ d ≤ 0.1, and a + b + c + d = 1. Exemplary lithiated nickel cobalt manganese oxides include Li(1+x)[Ni0.33Co0.33Mn0.33](1-x)O2, Li(1+x)[Ni0.5Co0.2Mn0.3](1-x)O2, Li(1+x)[Ni0.6Co0.2Mn0.2](1-x)O2, Li(1+x)[Ni0.7Co0.2Mn0.3](1-x)O2, Li(1+x)[Ni0.8Co0.1Mn0.1](1-x)O2each with x as defined above, and Li[Ni0.85Co0.13Al0.02]O2. In some embodiments, the material comprises lithiated nickel-cobalt aluminum oxides of formula Li[NihCoiAlj]O2+r, wherein h ranges from 0.8 to 0.95, i ranges from 0.1 to 0.3, j ranges from 0.01 to 0.10, and r ranges from zero to 0.4. In some embodiments, the material comprises lithiated manganese oxides of formula Li ’ (1+x)Mn2-x-y-zMyMzO4, wherein x ranges from zero to 0.2; y+z ranges from zero to 0.1; and M’is chosen from Al, Mg, Fe, Ti, V, Zr and Zn. In some embodiments, the material comprises a compound of formula xLi(1+1 / 3)M(2 / 3)O2 ∙yLiMO2∙zLiM’O2, wherein M comprises at least one metal of Mn, Ni, Co of oxidation state +4 , M’ is at least one transition metal, and 0 < x < 1, 0 < y < 1, 0 < z < 1 and x + y + z = 1.In the present disclosure, the term mixed hydroxide precipitate (MHP) means amixture of metal hydroxides, hydroxycarbonates, and / or carbonates comprisingnickel hydroxide, cobalt hydroxide and other metals, e.g., manganese. In some embodiments, the MHP is obtained by precipitating metal hydroxides from ametal salt solution. MHP typically comprises from 0 to 2 wt.% Li, from 10 to 50wt.% Ni, from 0.1 to 20 wt.% Co, from 0.01 to 15 wt.% Mn. Moisture content generally is in the range of from 20 to 60 wt.%, relative to the total weight of MHP. A typical range for D(50) is from 1 to 150 µm. In some embodiments, theMHP is an intermediate nickel product produced from laterite nickel ore, whichcontains both nickel and a small percentage of cobalt. MHP is typicallyproduced using a high-pressure acid leaching (HPAL) process. The mixedhydroxide precipitate (MHP) mostly consists of nickel hydroxide, but alsocontains valuable cobalt hydroxides and various other impurities, the main onebeing manganese. Ni content typically is 34-55 wt.%, Co content typically 1-4.5 wt.%.The process comprises a) leaching BM and / or CAM with sulfuric acid underinert atmosphere ("inert leaching"). In the context of the present disclosure, inertatmosphere means that the gas phase does not react with the solids and liquidspresent in the leaching step, i.e., neither oxidizes nor reduces BM and / or CAM nor any metal cations solubilized by the sulfuric acid. The inert atmosphere mainly comprises water vapor. Small amounts of air and / or hydrogen produced by reaction of BM and / or CAM with sulfuric acid may be present. At least at the end of step a), the concentration of hydrogen in the gas phase is below the lower explosion limit.Leaching step a) is performed at a temperature of from 70°C to 95°C, for a timeof from 0.5 to 4 hours, for instance, from 1 to 2 hours, and at an acidconcentration of from 0.7 kg to 2 kg acid per kg BM and / or CAM. In a subsequent step b), the mixture obtained in step a) is leached with sulfuricacid while injecting air into the mixture ("oxidative leaching").Leaching step b) is performed at a temperature of from 70°C to 90°C, for instance, from 85°C to 90°C, for a time of from 2 to 5 hours, and at a pH of from0.5 to 2.5, e.g., 1 to 1.5. It has been found that the temperature range is crucialfor achieving quantitative leaching of copper within the given residence time. If a temperature higher than 90°C is employed, incomplete leaching of copper is observed. At temperatures of less than 70°C, leaching is slow and is not completed during the given residence time.In a subsequent step c), MHP optionally is added to the mixture obtained in stepb). MHP can be used to adjust the pH of the mixture and increase content ofvalue metals such as nickel and / or cobalt and / or manganese in the mixture.In some embodiments, the mixture obtained in step c) is d) leached with sulfuricacid while a sulfur-containing reducing agent is added to the mixture ("reductiveleaching"). In an embodiment of the process, up to 2.0 mol / L of the sulfur-containing reducing agent per mol of Ni, Co, Mn added via CAM and / or MHPare added to the reaction mixture. The sulfur-containing reducing agent may be solid, liquid or gaseous. Examples of solid sulfur-containing reducing agents include Na2SO3, and Na2S2O5. Examples of liquid sulfur-containing reducing agents include H2SO3. Examples of gaseous sulfur-containing reducing agents include SO2. In some embodiments, the sulfur-containing reducing agent is selected from the group consisting of sulfur dioxide, H2SO3, Na2SO3, andNa2S2O5. In some embodiments, the sulfur-containing reducing agent is sulfurdioxide. When sulfur dioxide is injected into the mixture in the reductive leaching step,sulfur dioxide is added to the reaction mixture until it breaks through, i.e., sulfurdioxide can be detected in the rector exhaust. In an embodiment of the process,up to 2.0 mol / L sulfur dioxide per mol of Ni, Co, Mn added via CAM and / or MHP are added to the reaction mixture. Leaching step d) is performed at a temperature of 70°C to 95°C, for a time offrom 1 to 2 h, and at pH of from 0.5 to 2.0, for instance, from 1 to 1.7.In some embodiments, e) MHP is added to the mixture obtained in step d) to adjust the pH of the mixture to be in the range of from 1.5 to 2.5. Subsequently, f) solids are removed from the mixture obtained after the last step in the sequence of steps b) through e). Next, g) the pH of the solution obtained in step f) is adjusted to be in the range of from 1.5 to 2.5 by addition of sodium hydroxide and / or MHP, and copper ionsare subsequently removed from the solution by solvent extraction or byprecipitation, followed by solid / liquid separation. Solvent extraction is performedusing a solvent comprising a suitable extractant for copper ions. In some embodiments, the copper ions are removed from the solution by extraction witha 1:1 (by volume) mixture of 2-hydroxy-5-nonylacetophenone ketoxime and 5-nonylsalicylaldoxime (LIX 984N). In some embodiments of the process, the copper ions removed from the solution by solvent extraction in step g) are subsequently reduced to metallic copper. In some embodiments, the copper ions are reduced by cementation. In other embodiments, the copper ions arereduced by electrolysis (electrowinning). In some embodiments, the copper ionsare removed from the solution by solvent extraction or by precipitation followedby solid / liquid separation. In some embodiments, the copper ions are removedby precipitation of copper sulfide. To precipitate copper sulfide, sulfide, hydrogen sulfide, or thiosulfate ions are added to the solution obtained in step f). In some embodiments, Na2SO3is added to the solution obtained in step f) to precipitate copper sulfide. The precipitate is separated from the aqueous solution depleted of copper cations by solid / liquid separation, for instance, by filtration. Subsequently, h), the pH of the aqueous solution depleted of copper cationsobtained in step g) is h) adjusted to be in the range of from 3.0 to 5.0 byaddition of sodium carbonate and / or MHP, and generating a precipitate whichcomprises impurity cations of the group consisting of Al and Fe and impurityanions comprising P, F, Al, and / or Si present in the solution. In some embodiments, in step h) the pH of the solution obtained in step g) is h1) first adjusted to a value of from 3.0 to 4.0, generating a first precipitate which is removed from the solution, and h2) the pH of the mother liquor is subsequently adjusted to a value of from 4.5 to 5.0, generating a second precipitate. Finally, i) solids are removed from the mixture obtained in step h) to obtain an acidic aqueous solution comprising nickel, cobalt, manganese, and lithium ions. In some embodiments, the solids removed in step i) are recycled into one of steps a), b), and d).In some embodiments of the process, the acidic aqueous solution comprisingnickel, cobalt, manganese, and lithium ions obtained in step i) is further processed to recover nickel and / or cobalt and / or manganese, and / or lithium from the solution.The present disclosure also provides a production plant suitable for performingthe continuous process of the present disclosure.The production plant comprises a first CSTR module comprising n continuousstirred-tank reactors (CSTR) connected in series (n>=3). Each CSTR comprisesa dosing device for liquids, a dosing device for solids, and heating means. Atleast two of the n continuous stirred-tank reactors (CSTR) connected in series(n>=3) also comprise gas injection means. In some embodiments, the number nof CSTR connected in series in the first CSTR module is in the range of from 5to 8. Continuous stirred-tank reactors suitable for the first CSTR module areknown in the art. The production plant further comprises at least one first solid / liquid separation device configured to receive an effluent of the final CSTR of the first CSTRmodule, i.e., the last CSTR in the series of reactors.The production plant further comprises at least one solvent extraction (SX) unitconfigured to receive an effluent of the first solid / liquid separation device. TheSX unit comprises an extraction module and a scrubbing and stripping module.The effluent of the first solid / liquid separation device entering the SX unit isextracted with an organic solvent in the extraction module. The extractedaqueous phase leaves the extraction module as an aqueous effluent. The loaded organic phase is transferred to the scrubbing and stripping module,where it is scrubbed and stripped of metal cations with sulfuric acid to producean acidic aqueous solution comprising the metal cations from the organic phase. The organic phase is recycled to the extraction module, and the acidic aqueous solution comprising the metal cations from the organic phase leavesthe scrubbing and stripping module as an aqueous effluent. Suitable solventextraction (SX) units are known in the art. In some embodiments, the production plant further comprises an electrowinning (EW) unit configured to receive an aqueous effluent of the scrubbing and stripping module of the SX unit.The production plant further comprises a second continuous stirred-tank reactor(CSTR) configured to receive an aqueous effluent of the extraction module ofthe SX unit. The CSTR comprises a dosing device for liquids, heating means,and gas injection means. Suitable continuous stirred-tank reactors are known inthe art. The production plant further comprises at least one second solid / liquidseparation device configured to receive an effluent of the second CSTR.In some embodiments, the production plant further comprises a third continuousstirred-tank reactor (CSTR) configured to receive an aqueous effluent of the second solid / liquid separation device. The CSTR comprises a dosing device forliquids, heating means, and gas injection means. Suitable continuous stirred-tank reactors are known in the art. In these embodiments, the production plant further comprises at least one third solid / liquid separation device configured to receive an effluent of the third CSTR. In some embodiments of the production plant, the first, second, and third solid / liquid separation device each comprise a filter press. Detailed description of the drawing A schematic diagram of an exemplary production plant of the present disclosureis shown in Fig. 1. The figure also shows some of the material streams of anexemplary production process in the plant.The production plant comprises a first CSTR module 10 comprising three continuous stirred-tank reactors (CSTR) 11, 12, 13 connected in series. Each CSTR comprises a dosing device for liquids, a dosing device for solids, heatingmeans, and gas injection means. In an exemplary process, a black mass (BM)1000a is fed to the first CSTR 11 of the CSTR module 10, a cathode activematerial (CAM) 1000b is fed to the second CSTR 12 of the CSTR module 10,and a mixed hydroxide precipitate (MHP) 1000c is fed to the third CSTR 13 ofthe CSTR module 10, The production plant further comprises at least one first solid / liquid separation device 20 which is configured to receive an effluent 1001 of the first CSTR module 10. The at least one first solid / liquid separation device 20 is located downstream of the third CSTR 13 (the final CSTR of the series) of the first CSTR module 10. In the at least one first solid / liquid separation device 20, solids 2002 (leach residue) are removed from the effluent of the first CSTR module 10 by solid / liquid separation, e.g., filtration. The production plant further comprises a solvent extraction (SX) unit 30 which isconfigured to receive an aqueous effluent 2001 of the at least one firstsolid / liquid separation device 20. The SX unit 30 comprises an extraction module 31 and a scrubbing and stripping module 32. The aqueous effluent2001 of the at least one first solid / liquid separation device 20 entering the SXunit 30 is extracted with an organic solvent in the extraction module 31. The extracted aqueous phase leaves the extraction module 31 as an aqueous effluent 3001. The loaded organic phase is transferred to the scrubbing and stripping module 32, where it is scrubbed and stripped of metal cations with sulfuric acid to produce an acidic aqueous solution comprising the metal cations from the organic phase. The organic phase is recycled to the extraction module 31, and the acidic aqueous solution comprising the metal cations from the organic phase leaves the scrubbing and stripping module 32 as an aqueous effluent 3002. The production plant further comprises an electrowinning (EW) unit 80. The EW unit is configured to receive an aqueous effluent 3002 from the scrubbing and stripping module 32 of the SX unit 30. In the EW unit 80, metallic copper 8001 is produced from the copper ions present in the aqueous effluent 3002 byelectrochemical reduction (electrolysis). The acidic aqueous solution depleted ofcopper ions can be recycled to the scrubbing and stripping module 32 of the SX unit 30.The production plant further comprises a second continuous stirred-tank reactor(CSTR) 40 which is configured to receive an aqueous effluent 3001 of the extraction module 31 of the SX unit 30. The CSTR 40 comprises a dosing device for liquids, heating / cooling means, and gas injection means. In the CSTR 40, an alkaline solution (e.g., sodium hydroxide solution) is added to adjust thepH to a value of from 3.0 to 4.0 and to generate a first precipitate comprisingimpurity cations of the group consisting of Al and Fe and impurity anionscomprising P, F, Al, and / or Si present in the solution. The first precipitate ismainly comprised of metal hydroxides.The production plant further comprises at least one second solid / liquidseparation device 50 which is configured to receive an effluent 4001 of thesecond CSTR 40. In the at least one second solid / liquid separation device 50,the first precipitate comprising impurity cations of the group consisting of Al andFe and impurity anions comprising P, F, Al, and / or Si cations 5002 is removedfrom the effluent 4001 of the second CSTR 40 by solid / liquid separation, e.g.,filtration.The production plant further comprises a third CSTR 60 which is configured toreceive an aqueous effluent 5001 from the second solid / liquid separation device50. The third CSTR 60 comprises a dosing device for liquids andheating / cooling means. In the third CSTR 60, sodium carbonate and / or MHP1000c is added to adjust the pH to a value of from 4.5 to 5.0 and to generate asecond precipitate comprising residual impurity cations such impurity cations ofthe group consisting of Al and Fe and impurity anions comprising P, F, Al,and / or Si present in the aqueous effluent 5001. The second precipitate iscomprised of metal hydroxides and / or carbonates.The production plant further comprises at least one third solid / liquid separationdevice 70 which is configured to receive an effluent 6001 of the third CSTR 60.In the at least one third solid / liquid separation device 70, any solids 7002 in theeffluent 6001 of the third CSTR 60 are removed by solid / liquid separation, e.g.,filtration. As the solids 7002 may comprise significant amounts of value metalssuch as nickel, cobalt, and / or manganese, they can be recycled into the first CSTR module 10. The aqueous effluent 7001 of the third solid / liquid separation device 70 is an acidic aqueous solution comprising nickel, cobalt, manganese, and lithium cations, i.e., the final product of the production process. Examples Feed Cu Li Ni Co MnI 4.2 wt.% 3.5 wt.% 14.5 wt.% 7.5 wt.% 4.5 wt.%II 4.4 wt.% 3.6 wt.% 15.5 wt.% 7.2 wt.% 3.8 wt.%III 8.5 wt.% 3.9 wt.% 16.4 wt.% 5.5 wt.% 5.1 wt.%IV 0.0 wt.% 0.26 wt.% 15.6 wt.% 13.6 wt.% 14.5 wt.%V 4.5 wt.% 3.6 wt.% 14.3 wt.% 7.5 wt.% 4.5 wt.%VI 6.7 wt.% 3.2 wt.% 15.1 wt.% 6.0 wt.% 5.3 wt.%VII 0.0 wt.% 6.5 wt.% 34.0 wt.% 11.0 wt.% 10.9 wt.%Comparative Example 175 g of a NCM battery black mass III was suspended in 300 g deionized water,then heated to 90°C and was subsequently treated with 90 g H2SO4. Afterdosing had been finished, the reaction mixture was stirred for 7 h under inertatmosphere. The suspension was subsequently filtered and the solid waswashed and dried. 367.1 g Filtrate 1 and 28.6 g Solids a were obtained.Example 2226.1 g of filtrate 1 was heated to 90°C. The pH then was adjusted from 0.3 to1.6 using 11.6 g MHP IV stemming from a battery recycling process, and havinga moisture content of 25.9%. The solids introduced were completely digested yielding filtrate 2. Comparative Example 3100 g of a NCM battery black mass I was suspended in 400 g deionized water,then heated to 95°C and was subsequently treated with 85 g H2SO4. Afterdosing was finished, the reaction mixture was stirred with 700 rpm for 2 h. Thenthe inert gas atmosphere was exchanged with ambient air, which was passedthrough the mixture with a flow rate of 20 NL / h. After stirring for 3 h, the slurryhad reached an ORP of −64 mV vs. Ag / AgCl. Aeration was stopped and 12.2 gof SO2 were introduced into the mixture over the course of 2 h. The suspensionwas then filtered and the solids were washed and dried. 416 g Filtrate 3 and31 g Solids b were obtained. As can be seen from the table, almost no copperwas dissolved by the leaching process at 95°C. Example 4100 g of a NCM battery black mass I was suspended in 400 g deionized water,then heated to 95°C and was subsequently treated with 88 g H2SO4. Afterdosing was finished, the reaction mixture was stirred with 700 rpm for 2 h. Then,mixture was cooled down to 80°C and the inert gas atmosphere was exchangedwith ambient air, which was passed through the mixture at a flow rate of20 NL / h. After stirring for 3 h, the slurry had reached an ORP of +297 mV vs.Ag / AgCl. Aeration was stopped and 18 g of SO2 were introduced into themixture over the course of 2 h. The suspension was then filtered and the solidswere washed and dried. 431 g Filtrate 4 and 18.6 g Solids c were obtained. Ascan be seen from the table, almost all of the copper was dissolved by the leaching process at 80°C. Example 575 g of a NCM battery black mass V was suspended in 300 g deionized water,then heated to 90°C and was subsequently treated with 82.5 g H2SO4. Afterdosing was finished, the reaction mixture was stirred with 700 rpm for 2 h. Then,the inert gas atmosphere was exchanged with ambient air, which was passedthrough the mixture with a flow rate of 20 NL / h. After 2 h a Cu concentration of0.62 wt.% was measured in the aqueous solution. Stirring was continued for 3 hafter which the slurry had reached an ORP of +437 mV vs. Ag / AgCl and a pH of0. The suspension then was filtered and the solids were washed and dried.345 g Filtrate 5 and 9.7 g Solids d were obtained.Example 675 g of a NCM battery black mass V was suspended in 300 g deionized water,then heated to 90°C and was subsequently treated with 75 g H2SO4. Afterdosing was finished, the reaction mixture was stirred with 700 rpm for 2 h. Then,the inert gas atmosphere was exchanged with ambient air, which was passedthrough the mixture with a flow rate of 20 NL / h. After 1 and 2 h a Cuconcentration of 0.67 wt.% and 0.79 wt.%, respectively, was measured in theaqueous solution. Stirring was continued for 2 h after which the slurry hadreached an ORP of +404 mV vs. Ag / AgCl and a pH of 0.5. The suspension wasthen filtered and the solids were washed and dried. 321 g Filtrate 6 and 5.1 gSolids e were obtained.Example 789 g of a mixture II of NCM and NCA battery black mass in a ratio of 84:16 wassuspended in 356 g deionized water, then heated to 90°C and wassubsequently treated with 107 g H2SO4. After dosing was finished, the reactionmixture was stirred for 2 h. Then the inert gas atmosphere was exchanged withambient air, which was passed through the mixture at a flow rate of 20 NL / h andthe temperature was reduced to 85 C. After stirring for 5 h, the suspension wasfiltered and the solids were washed and dried. 452 g Filtrate 7 and 32.5 g Solidsf were obtained.Example 875 g of a NCM black mass VI that had not been thermally treated wassuspended in 300 g deionized water, then heated to 90°C and wassubsequently treated with 75 g H2SO4. After dosing was finished, the reactionmixture was stirred with 700 rpm for 2 h. Then the inert atmosphere wasreplaced by air, which was passed through the mixture at a flow rate of 20 NL / h.The reaction was stirred for 5 h, after which the heating was stopped. Thesuspension was filtered and the solids were washed and dried. 362.6 g Filtrate8 and 24.9 g Solids g were obtained.Example 975 g of a NCM black mass VI that had not been thermally treated wassuspended in 300 g deionized water, then heated to 90°C and wassubsequently treated with 75 g H2SO4. After dosing was finished, the reactionmixture was stirred with 700 rpm for 2 h. Then the inert atmosphere wasreplaced by air, which was passed through the mixture at a flow rate of 20 NL / h.After stirring for 3 h, the air flow was stopped and Na2S2O5 was added over thecourse of 2 h until the ORP value was stagnant. The suspension then wasfiltered and the solids were washed and dried. 376.5 g Filtrate 9 and 21.4 gSolids h were obtained.Example 1020 g NCM CAM material VII and 15 g Na2S2O5 were suspended in 100 g DIwater. Then the reaction mixture was heated to 90°C and 20 mL H2SO4 96%was added and the reaction was stirred for 260 min. The suspension then wasfiltered and the solids were washed and dried. 165 g Filtrate 10 and 3.5 g Solidsi were obtained. Example 1120 g NCM CAM material VII was suspended in 100 g DI water. Then thereaction mixture was heated to 90°C and 20 mL H2SO496% was added and thereaction was stirred for 180 min. The suspension then was filtered and thesolids were washed and dried. 153 g Filtrate 11 and 15.2 g Solids j wereobtained. Example 12133 g of a NCM black mass VI that had not been thermally treated wassuspended in 400 g deionized water, then heated to 90°C and wassubsequently treated with 146.7 g H2SO4. After dosing was finished, thereaction mixture was stirred with 610 rpm for 2 h. Then the inert atmospherewas replaced by air, which was passed through the mixture at a flow rate of30 NL / h. After stirring for 3 h, the air flow was stopped and Na2S2O5 was addedover the course of 2 h until the ORP value was stagnant. The suspension thenwas filtered and the solids were washed and dried. 540 g Filtrate 12 and 49.3 gSolids k were obtained.465 g of Filtrate 12 was heated to 85 °C and Na2S2O3 was quickly added to thereaction mixture in a molar ratio of 1.2, relative to the Cu-content in the solution. The suspension was stirred for 2 h, then filtered and the solids were washedand dried. 540 g Filtrate 13 and 49.3 g Solids l were obtained.The following Tables 1-3 summarize the compositions of the filtrates and the solids obtained in the Examples, as determined by ICP-OES analytics, and the calculated yields of the value elements recovered. The term "n.d." signifies that the corresponding parameter has not been analytically determined.Table 1. Composition of the filtrates as determined by ICP-OES analysis.Filtrate Co Cu Li Mn Ni1 1.0 wt % 0.0 wt % 0.70 wt % 0.96 wt % 2.9 wt %2 1.4 wt % 0.0 wt % n.d. 1.3 wt % 3.4 wt %3 1.4 wt % 0.0 wt % 0.67 wt % 0.9 wt % 2.8 wt %4 1.4 wt % 0.8 wt % 0.67 wt % 0.9 wt % 2.5 wt %5 1.4 wt % 0.79% 0.67 wt % 0.84 wt % 2.6 wt %6 1.4 wt % 0.9 wt % 0.7 wt % 0.86 wt % 2.9 wt %7 1.3 wt % 1.0 wt % 0.6 wt % 0.71 wt % 3.0 wt %8 0.96 wt % 1.2 wt % 0.57 wt % 0.83 wt % 2.4 wt %9 0.94 wt % 1.1 wt % 0.54 wt % 0.8 wt % 2.3 wt %10 1.3 wt % n.d. n.d. 1.2 wt % 4.0 wt %11 0.69 wt % n.d. n.d. 0.07 wt % 2.2 wt %12 1.3 wt % 1.4 wt % 0.72 wt % 1.1 wt % 3.3 wt %13 1.2 wt % 0.007 wt % n.d. 0.92 wt % 2.9 wt %Table 2. Composition of the dry solids as determined by ICP-OES analysis Solids Co Cu Li Mn Nia 0.4 wt % 22.0 wt % 0.2 wt % 0.2 wt % 1.9 wt %b 0.6 wt.% 9.8 wt % 0.2 wt % 0.3 wt % 2.6 wt %c 1.0 wt % 1.0 wt % 0.26 wt % 0.3 wt % 5.1 wt %d 0.21 wt % 0.80 wt % 0.15 wt % 0.29 wt % 1.1 wt %e 1.00 wt % 0.90 wt % 0.44 wt % 0.72 wt % 5.3 wt %f 0.21 wt % 0.42 wt % 0.13 wt % 0.17 wt % 1.2 wt %g 1.2 wt % 0.39 wt % 0.49 wt % 1.10 wt % 2.6 wt %h 0.1 wt % 0.67 wt % 0.08 wt % 0.07 wt % 0.44 wt %i 0.85 wt % n.d. n.d. 0.79 wt % 2.7 wt %j 9.7 wt % n.d. n.d. 17.6 wt % 28.5 wt %k n.d. 0.70 wt % 0.25 wt % n.d. 1.6 wt %l n.d. 62 wt % n.d. n.d. 0.07 wt %Table 1. Yields of selected elements in the filtratesFiltrate Co Cu Li Mn Ni1 97.4% 0.0% 98.0% 98.3% 95.8%3 96.7% 0.0% 97.6% 97.3% 92.6%4 96.7% 94.1% 98.2% 98.3% 91.3%5 99.6% 97.7% 99.5% 99.2% 99.0%6 99.1% 98.6% 99.2% 98.9% 97.5%7 98.9% 97.3% 98.6% 98.4% 97.4%8 93.4% 98.1% 94.9% 93.1% 94.3%9 99.5% 97.1% 99.3% 99.6% 99.2%10 99.6% n.d. n.d. 99.7% 99.7%11 51.5% n.d. n.d. 11.2% 53.9%As can be seen from Fig.2, at a lower temperature of 85°C, Cu was leached faster than at 90°C, even though less acid was used. At the higher temperature, Cu is also dissolved quantitatively, but it takes significantly longer and requires a larger amount of acid, increasing overall raw material consumption. Examples 8 through 11 exemplify the optional use of a reducing agent in case transition metals with higher oxidation states than +2 are present in the feed. Without the addition, lower yields of Co, Mn and Ni were obtained in examples 9 and 11. Determination of Metal Yields Metal yields (MYE) were determined using element contents determined by ICP- OES. If not stated otherwise, metal yields were determined by using the element content determined in the solid residue. The following formulas were utilized: 1−^(^^^) ^(^^^^)= ^^^ (1)^(^^^) = ^^^^^^^ ∗ ^(^^) (2)wherein E denotes a given element, FC denotes the dry solid, EICP−FC is the determined percentage-based content in the dry solid, m(EFC) is the weight content of the element in the dry solid, m(EMax) is the maximum yield of an element based on the amount of the element found over all fractions, and MYEis the metal yield of the respective element in the filtrate.

[0002] List of reference signs10 CSTR module11 CSTR12 CSTR13 CSTR20 First solid / liquid separation unit30 SX unit31 Extraction module of SX unit32 Scrubbing and stripping module of SX unit40 Second CSTR50 Second solid / liquid separation unit60 Third CSTR70 Third solid / liquid separation unit80 EW unit1000a black mass (BM)1000b cathode active material (CAM)1000c mixed hydroxide precipitate (MHP)1001 Aqueous effluent of CSTR module2001 Aqueous effluent first solid / liquid separation unit2002 Solids (leach residue)3001 Aqueous effluent of extraction module of SX unit3002 Aqueous effluent of scrubbing and stripping module of SX unit4001 Effluent of second CSTR5001 Aqueous effluent of second solid / liquid separation unit5002 Solids (impurity metal hydroxides)6001 Effluent of third CSTR7001 Aqueous effluent of third solid / liquid separation unit (product)7002 Solids (impurity metal hydroxides)8001 metallic copper

Claims

BASF SE B25.133P-WO67056 Ludwigshafen am Rhein 19.12.2024 / lg / np / jlClaims1. A continuous process for preparing an acidic aqueous solution comprisingnickel, cobalt, manganese, and lithium cations, the process comprisinga) leaching black mass (BM) and / or cathode active material (CAM)with sulfuric acid under inert atmospherei. at a temperature of from 70°C to 95°C,ii. for a time of from 0.5 to 4 h,iii. with an amount of acid ranging from 0.7 kg to 2 kg acid perkg BM and / or CAM,b) leaching the mixture obtained in step a) with sulfuric acid whileinjecting air into the mixture i. at a temperature of from 70°C to 90°C,ii. for a time of from 2 to 5 h,iii. at a pH of 2.5 or less,c) optionally, adding mixed hydroxide precipitate (MHP) to themixture obtained in step b), d) optionally, leaching the mixture obtained in step c) with sulfuricacid while adding a sulfur-containing reducing agent to the mixture, i. at a temperature of 70°C to 95°C,ii. for a time of from 1 to 2 h,iii. at pH of 2.0 or less,e) optionally, adding MHP to the mixture in step d) to adjust the pH ofthe mixture to be in the range of from 1.5 to 2.5,f) removing solids from the mixture obtained after the last step in thesequence of steps b) through e), g) adjusting the pH of the solution obtained in step f) to be in therange of from 1.5 to 2.5 by addition of sodium hydroxide and / or- 2 -MHP, and subsequently removing copper cations from thesolution by solvent extraction, or by precipitation of copper sulfide,followed by solid / liquid separation, h) adjusting the pH of the aqueous solution depleted of coppercations obtained in step g) to be in the range of from 3.0 to 5.0 byaddition of sodium carbonate, calcium carbonate and / or MHP, andgenerating a precipitate, i) removing solids from the mixture obtained in step h) to obtain theacidic aqueous solution comprising nickel, cobalt, manganese, and lithium cations.

2. The process of claim 1, wherein the sulfur-containing reducing agentadded in step d) is solid, liquid or gaseous.

3. The process of claim 2, wherein the sulfur-containing reducing agentadded in step d) is selected from the group consisting of sulfur dioxide, H2SO3, Na2SO3, and Na2S2O5.

4. The process of any one of claims 1 to 3, wherein in step h), the pH of thesolution obtained in step g) first is adjusted to a value of 3.0 to 4.0, h1) generating a first precipitate which is removed from the solution, and h2)the pH of the mother liquor is subsequently adjusted to a value of 4.5 to 5.0, generating a second precipitate.

5. The process of any one of claims 1 to 4, wherein the solids removed instep i) are recycled into one of steps a), b), and d).

6. The process of any one of claims 1 to 5, wherein the copper cations areremoved from the solution by extraction with a 1:1 by volume mixture of 2-hydroxy-5-nonylacetophenone ketoxime and 5-nonylsalicylaldoxime.

7. The process of any one of claims 1 to 6, wherein the copper cationsremoved from the solution by solvent extraction in step g) aresubsequently reduced to metallic copper.- 3 -8. The process of claim 7, wherein the reduction of the copper cations iseffected by electrowinning.

9. The process of any one of claims 1 to 5, wherein the copper cations areremoved from the solution by precipitation of copper sulfide, followed bysolid / liquid separation.

10. The process of claim 9, wherein sodium thiosulfate is added in step g) toprecipitate copper sulfide.

11. The process of any one of claims 1 to 10, wherein the acidic aqueoussolution comprising nickel, cobalt, manganese, and lithium cations obtained in step i) is further processed to recover nickel and / or cobalt and / or manganese and / or lithium cations from the solution.

12. A production plant comprising(1) a first CSTR module (10) comprising n continuous stirred-tankreactors (CSTR) (11, 12, 13) connected in series (n>=3), eachCSTR (11, 12, 13) comprisingi. a dosing device for liquids,ii. a dosing device for solids,iii. heating means,and at least two of the n continuous stirred-tank reactors (CSTR)(11, 12, 13) connected in series (n>=3) comprisingiv. gas injection means,(2) at least one first solid / liquid separation device (20) configured toreceive an effluent (1001) of the first CSTR module (10),(3) at least one solvent extraction (SX) unit (30) configured to receivean effluent (2001) of the first solid / liquid separation device (20), theSX unit (30) comprising i. an extraction module (31),ii. a scrubbing and stripping module (32),- 4 -(4) optionally, an electrowinning (EW) unit (80) configured to receive anaqueous effluent (3002) of the scrubbing and stripping module (32)of the SX unit (30),(5) a second continuous stirred-tank reactor (CSTR) (40) configured toreceive an aqueous effluent (3001) of the extraction module (31) of the SX unit (30), the second CSTR (40) comprising i. a dosing device for liquids,ii. heating means,iii. gas injection means,(6) at least one second solid / liquid separation device (50) configured toreceive an effluent (4001) of the second CSTR (40), (7) a third continuous stirred-tank reactor (CSTR) (60) configured toreceive an aqueous effluent (5001) of the second solid / liquid separation device (50), the third CSTR (60) comprising i. a dosing device for liquids,ii. heating means,iii. gas injection means,(8) at least one third solid / liquid separation device (70) configured toreceive an effluent (6001) of the third CSTR (60).

13. The production plant of claim 12, wherein the number n of CSTRconnected in series in the first CSTR module (10) is in the range of from 5to 8.

14. The production plant of claim 12 or 13, wherein the first solid / liquidseparation device (20), the second solid / liquid separation device (50), and the third solid / liquid separation device (70) each comprise a filter press.

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