Continuous process and production plant for recovering metals from acidic aqueous solutions

Abstract

The present disclosure relates to a continuous process and a production plant for recovering metal salts from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations.

Description

Technology Field

[0001] The project leading to this application was funded by the Bundesministerium für Wirtschaft und Klimaschutz and State of Brandenburg (DE; FKZ:16BZF101A / B); and the applicant bears responsibility for all disclosures of this application.

[0002] Field of invention

[0003] The present disclosure relates to a continuous process and a production plant for recovering metal salts from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations. Background Technology

[0004] 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. Therefore, there is a need for devices and processes for recycling lithium-ion battery materials.

[0005] WO 2023 / 054621 A1 discloses a method for recovering valuable metals from a spent lithium-ion battery, comprising: a dissolution step for obtaining an acid solution by dissolving an active material powder obtained by pre-treating the spent lithium-ion battery in an inorganic acid; and a solvent extraction step for separating manganese, cobalt, and nickel among the metals contained in the active material powder from the acid solution through solvent extraction to obtain a first lithium salt aqueous solution as the residual liquid of the solvent extraction.

[0006] WO 2020 / 124130 A1 discloses a method for recovering a metal from a feed stream comprising one or more valuable metals and lithium. The method comprises the steps of: treating the feed stream with sulfuric acid leaching to form a slurry comprising a pregnant leaching solution of a soluble metal salt and a solid residue; separating the pregnant leaching solution and the solid residue; applying the pregnant leaching solution to one or more separate solvent extraction steps, wherein each solvent extraction step recovers one or more valuable metals from the pregnant leaching solution and the residual pregnant leaching solution comprises lithium; and recovering lithium from the pregnant leaching solution.

[0007] U.S. Patent Publication No. 2022 / 205064 A1 discloses a hydrometallurgical solvent extraction process for recovering valuable metal ion species, such as any of manganese, cobalt, nickel, and / or lithium, from a solution containing mixed-metal ions derived from recycled electronic products and / or batteries by separating valuable metal ions using selective stripping technology.

[0008] The object of the present disclosure is to provide an improved recirculation plant for lithium-ion battery materials and an improved recirculation process for lithium-ion battery materials.

[0009] Summary of the Invention

[0010] The present disclosure provides a continuous process for recovering metal salts from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations. The process comprises removing impurity cations of the group consisting of Al and Fe cations and impurity anions including P, F, or Si present in the solution by precipitation, and then removing manganese cations and any impurity cations of the group consisting of Ca, Cu, Zn, and Cd from the solution by solvent extraction, recovering cobalt cations by solvent extraction from an aqueous solution depleted of manganese cations and impurity cations, recovering nickel cations by solvent extraction from an aqueous solution depleted of cobalt cations, precipitating magnesium hydroxide from an aqueous solution depleted of nickel cations and recovering solid magnesium hydroxide, and recovering lithium cations by solvent extraction from an aqueous solution depleted of magnesium cations.

[0011] The present disclosure also provides a production plant suitable for carrying out the continuous process of the present disclosure. Brief explanation of the drawing

[0012] FIG. 1 is a schematic diagram of an exemplary production plant of the present disclosure. FIG. 2 is a schematic diagram of a section of another exemplary production plant of the present disclosure. Specific details for implementing the invention

[0013] The present disclosure provides a continuous process for recovering metal salts from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations. In some embodiments, the acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations is obtained by leaching a lithium-ion battery material with sulfuric acid. Examples of suitable lithium-ion battery materials for preparing an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations include black mass, cathode active material, and mixed metal hydroxide (MHP). The acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations may additionally contain cations of other metals such as copper, iron, aluminum, magnesium, calcium, and / or titanium; as well as anions including phosphorus, fluoride, silicon, and / or aluminum.

[0014] The above continuous process of the present disclosure is

[0015] a) Optionally, adjusting the pH value of the solution to a value within the range of 1.5 to 2.5 and recovering copper from the solution by solvent extraction or by solid / liquid separation after copper sulfide precipitation;

[0016] b) adjusting the pH of an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations to a range of 3.0 to 4.0 by adding sodium carbonate, and then precipitating impurity cations of a group consisting of Al and Fe cations present in the solution and impurity anions containing P, F, or Si from the solution;

[0017] c) a step of removing the solid from the mixture obtained in step b) above;

[0018] d) adjusting the pH of the acidic aqueous solution obtained in step c) to a range of 4.5 to 5.0 by adding sodium carbonate, and then precipitating impurity cations of the group consisting of Al and Fe cations present in the solution and impurity anions including P, F, or Si from the solution;

[0019] e) a step of removing the solid from the mixture obtained in step d) above;

[0020] f) adjusting the pH of the acidic aqueous solution obtained in step e) to a range of 2 to 4, and then removing any residual impurity cations from the group consisting of manganese cations and Ca, Cu, Zn, and Cd cations present in the solution by solvent extraction to obtain an aqueous solution depleted of manganese cations and impurity cations and a solvent containing manganese cations and impurity cations; and scrubbing and stripping the solvent containing manganese cations and impurity cations with sulfuric acid to obtain an acidic aqueous solution containing manganese cations and impurity cations;

[0021] g) adjusting the pH of the aqueous solution depleted of manganese cations and impurity cations obtained in step f) to a range of 3 to 6; subsequently removing cobalt cations from the solution by solvent extraction to obtain an aqueous solution depleted of cobalt cations and a solvent containing cobalt cations; and scrubbing and stripping the solvent containing cobalt cations with sulfuric acid to obtain an acidic aqueous solution containing cobalt cations;

[0022] h) adjusting the pH of the aqueous solution depleted of cobalt cations obtained in step g) to a range of 5 to 7.5; subsequently removing nickel cations from the solution by solvent extraction to obtain an aqueous solution depleted of nickel cations and a solvent containing nickel cations; and scrubbing and stripping the solvent containing nickel cations with sulfuric acid to obtain an acidic aqueous solution containing nickel cations;

[0023] i) a step of adding sodium hydroxide to the nickel cation-depleted aqueous solution obtained in step h), adjusting the pH to a range of 10 to 12.5, and precipitating magnesium hydroxide from the solution;

[0024] j) a step of removing the solid from the mixture obtained in step i) above;

[0025] k) adjusting the pH of the aqueous solution obtained in step j) to a range of 8 to 12, e.g., 8 to 10, e.g., 8 to 9, and then removing lithium cations from the solution by solvent extraction to obtain an aqueous solution depleted of lithium cations and a solvent containing lithium cations; and scrubbing and stripping the solvent containing lithium cations with sulfuric acid to obtain an acidic aqueous solution containing lithium cations.

[0026] Includes

[0027] Solvent extraction (SX) is a useful method for separating and purifying metal cations from aqueous solutions or leachates. Purifying metal cations present in a hydrated form in an aqueous solution can be difficult because it is challenging to transfer the cations into a low-polarity organic solvent layer. To transfer hydrated metal cations into the organic phase, the metal cations must be in the form of an uncharged complex, and the metal cations must be capable of removing water molecules from the hydrated complex.

[0028] A solvent extracting agent enables metal cations to form uncharged complexes and remove water molecules. Extraction efficiency depends, for example, on the type of solvent extracting agent, the equilibrium pH, and the metal cations in the aqueous solution. Extraction efficiency can also be influenced, for example, by the concentration of the solvent extracting agent, the ratio of the solvent extracting agent to the aqueous solution, and the composition and concentration of the stripping solution.

[0029] In some embodiments, solvent extraction is a two-step process (or a three-step process if impurities must be scrubbed before stripping). The scrubbing step (step 2) is performed, if necessary, between the step of extracting the target chemical species into the organic phase (step 1) and the stripping step (step 3).

[0030] In the first step, a solvent extractant (a non-polar weak acid) is dissolved in an organic liquid (a diluent) such as kerosene. This mixture forms an extractant solution. This solution is brought into contact with / mixed with an acidic aqueous solution, and the extractant extracts metal cations from the solution. Depending on the selected extractant, different metal cations can be extracted from the acidic aqueous solution.

[0031] In a second optional step, impurities are removed from the organic phase (extractant solution) by scrubbing. In some embodiments of the process, scrubbing is performed by selectively reversing the reaction by treating with a fresh scrub solution (aqueous) containing chemicals for removing impurity metals from the organic phase. The scrub solution used is typically combined with an SX feed. The scrubbed organic phase containing the metal of interest is separated from the aqueous phase and transferred to a stripping step. In some embodiments, diluted sulfuric acid is used for scrubbing. In some embodiments, a solution containing the same metal cations extracted from an acidic aqueous solution is used for scrubbing. In some embodiments, an aqueous solution containing metal cations obtained after stripping the organic phase, i.e., the product of the solvent extraction procedure, is used for scrubbing.

[0032] Next, when the extractant solution containing metal cations is brought into contact with an acid solution (strong acid), the metal cations H + It is replaced by. Conversely, metal cations move into an acidic aqueous solution. This solution is called a loaded stripping solution. The process of moving metal cations back into the aqueous phase is called stripping.

[0033] In step a), which is an optional first step of the process of the present disclosure, copper is recovered by a first solvent extraction from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations. In some embodiments of the process, the solvent extractant is LIX984N, which is a 1:1 mixture of 5-nonyl salicyl aldoxime and 2-hydroxy-5-nonyl acetophenone.

[0034] In some embodiments, the first solvent extraction includes the following procedures:

[0035] - Adding an alkaline solution to an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations to adjust the pH value of the solution to a value in the range of 1.5 to 2.5;

[0036] - Adding a solvent extractant to an acidic aqueous solution,

[0037] - Homogenizing a mixture of an acidic aqueous solution and a solvent extractant,

[0038] - Separating the mixture into a layer of Cu-depleted acidic aqueous solution and a layer of Cu-containing solvent extractant,

[0039] - Separating a layer of Cu-containing solvent extractant from a layer of Cu-depleted acidic aqueous solution,

[0040] - Mixing a separated solvent extractant containing Cu with a second aqueous acidic solution,

[0041] - Homogenizing a mixture,

[0042] - Separating the mixture into a layer of a second aqueous solution containing copper and a layer of a solvent extractant, and

[0043] - Separating an aqueous solution containing Cu from a layer of solvent extractant.

[0044] In some embodiments, the first solvent extraction is a two-step process (or a three-step process if impurities must be scrubbed before stripping). If necessary, an optional scrubbing step (step 2) is performed between the step of extracting the target chemical species into the organic phase (step 1) and the stripping step (step 3).

[0045] In the first step, a solvent extractant (a non-polar weak acid) is dissolved in an organic liquid such as kerosene (a diluent). This mixture forms an extractant solution. This solution is brought into contact with / mixed with an acidic aqueous solution, from which the extractant selectively extracts copper cations.

[0046] In the second optional step, impurities are removed from the organic phase (extractant solution) by scrubbing.

[0047] Subsequently, when the extractant solution containing copper cations is brought into contact with an acid solution (strong acid), the copper cations H +It is replaced by... Conversely, copper cations move into an acidic aqueous solution. This solution is called a loaded stripping solution. The process of moving copper cations back into the aqueous solution is called stripping.

[0048] In some embodiments, copper is recovered by solid / liquid separation after precipitation. In some embodiments, copper ions are removed by the precipitation of copper sulfide. To precipitate copper sulfide, sulfide, hydrogen sulfide, or thiosulfate ions are added to the solution. In some embodiments, Na2SO3 is added to the solution to precipitate copper sulfide. The precipitate is separated from the copper cation-depleted aqueous solution by solid / liquid separation, e.g., filtration.

[0049] The Cu-depleted acidic aqueous solution obtained by solid / liquid separation after the first solvent extraction or after the precipitation of copper sulfide is further processed in step b).

[0050] In step b) of the process of the present disclosure, impurities are precipitated from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations. The precipitation involves the addition of sodium carbonate or calcium carbonate. Impurity cations of the group consisting of Al and Fe cations and impurity anions containing P, F, or Si present in the solution are precipitated from the solution as salts.

[0051] The impurities include one or more selected from iron, aluminum, magnesium, calcium, titanium, manganese, residual copper, fluoride, silicate, and phosphate. Precipitation involves adding a sodium carbonate solution or calcium carbonate to an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations to adjust the pH value of the solution to a value in the range of 3.0 to 4.0. In some embodiments of the process, air is introduced into the solution to oxidize any present Fe(II) to Fe(III). Iron, aluminum, magnesium, titanium, and copper are precipitated from the solution as hydroxides and / or oxides—hydroxides and / or carbonates, fluoride and / or phosphates, and are removed from the mother liquor by solid-liquid separation, e.g., filtration, in a subsequent step c).

[0052] The mother liquor is further processed in the second precipitation step d). Precipitation involves adding a sodium carbonate solution or calcium carbonate to the mother liquor obtained in step c) to adjust the pH value of the solution to a value in the range of 4.5 to 5.0. Impurity cations of the group consisting of Al and Fe cations present in the solution and impurity anions including P, F, or Si are precipitated from the solution. Iron, aluminum, magnesium, titanium, and copper are precipitated from the solution as hydroxides and / or oxide-hydroxides and / or carbonates, fluorides and / or phosphates, and are removed from the mother liquor by solid-liquid separation, e.g., filtration, in the subsequent step e). In some embodiments of the process, some manganese is also precipitated as manganese carbonate. Since the precipitate obtained in step e) may contain a significant amount of valuable metals, particularly nickel, it can be recycled to the leaching step and used to produce an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations.

[0053] Using the two-step precipitation and separation process of steps b) to e) maximizes the precipitation of Al, Fe, and F from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations, and thus the removal of impurities, which minimizes the co-precipitation of valuable metals and thus minimizes the loss of nickel, cobalt, manganese, and lithium.

[0054] The above process further comprises f) adjusting the pH of the mother liquor obtained in step e) to a range of 2 to 4, and subsequently removing any residual impurity cations of the group consisting of Ca, Cu, Zn and Cd present in the solution by solvent extraction to obtain an aqueous solution depleted of manganese cations and impurity cations and a solvent containing manganese cations and impurity cations, and scrubbing and stripping the solvent containing manganese cations and impurity cations with sulfuric acid to obtain an acidic aqueous solution containing manganese cations and impurity cations.

[0055] The above process further comprises the step of g) adjusting the pH of the aqueous solution depleted of manganese cations and impurity cations obtained in step f) to a range of 3 to 6, and then removing cobalt cations from the solution by solvent extraction to obtain an aqueous solution depleted of cobalt cations and a solvent containing cobalt cations, and scrubbing and stripping the solvent containing cobalt cations with sulfuric acid to obtain an acidic aqueous solution containing cobalt cations. In some embodiments of the process, a diluted loaded strip liquor is used for scrubbing.

[0056] The above process further comprises the step of h) adjusting the pH of the aqueous solution depleted of cobalt cations obtained in step g) to a range of 5 to 7.5, and then removing nickel cations from the solution by solvent extraction to obtain an aqueous solution depleted of nickel cations and a solvent containing nickel cations, and scrubbing and stripping the solvent containing nickel cations with sulfuric acid to obtain an acidic aqueous solution containing nickel cations. In some embodiments of the process, a diluted loaded strip liquid is used for scrubbing.

[0057] The above process further comprises the step of i) adding sodium hydroxide to the nickel cation-depleted aqueous solution obtained in step h) to adjust the pH to a range of 10 to 12.5 and precipitating magnesium hydroxide from the solution. This step is essential for the recovery of lithium cations by subsequent solvent extraction. Magnesium cations have been found to interfere with the phase separation of the organic phase from the aqueous phase in the solvent extraction of lithium-containing solutions. Without the prior removal of magnesium cations from the solution, the solvent extraction of lithium cations does not function properly.

[0058] The above process further includes j) a step of removing a solid from the mixture obtained in step i).

[0059] The above process further comprises the steps of: k) adjusting the pH of the aqueous solution obtained in step j) to a range of 8 to 12, e.g., 8 to 10, e.g., 8 to 9; and then removing lithium cations from the solution by solvent extraction to obtain an aqueous solution depleted of lithium cations and a solvent containing lithium cations; and scrubbing and stripping the solvent containing lithium cations with sulfuric acid to obtain an acidic aqueous solution containing lithium cations. Since the aqueous solution obtained in step j) also contains a high concentration of sodium cations, the recovery of lithium cations from the solution by solvent extraction provides an advantage over the precipitation of lithium salts, such as lithium carbonates, by minimizing contamination of the acidic aqueous solution containing lithium cations by sodium cations and consequently the sodium content in the lithium salt recovered from the acidic aqueous solution containing lithium cations.

[0060] In some embodiments, the process further comprises: l) adjusting the pH of the acidic aqueous solution containing the manganese cation and impurity cation obtained in step f) to a range of 6.8 to 8.5 (e.g., 7.3 to 8) by adding sodium carbonate, and precipitating manganese carbonate from the solution. In other embodiments, the process further comprises: l) adjusting the pH of the acidic aqueous solution containing the manganese cation and impurity cation obtained in step f) to a range of 6.8 to 8.5 (e.g., 7.3 to 8) by adding sodium hydroxide, and precipitating manganese hydroxide from the solution. Following step l), m) removing the solid from the mixture obtained in step l).

[0061] In some embodiments, the process further comprises the steps of: n) adding sodium hydroxide to the aqueous solution obtained in step m), adjusting the pH of the solution to a range of 10 to 12.5, and precipitating a metal hydroxide from the solution.

[0062] In some embodiments, the process further includes the step of removing a solid from the mixture obtained in step n).

[0063] In some embodiments, the process further comprises the step of p) crystallizing cobalt sulfate from an acidic aqueous solution containing cobalt cations obtained in step g).

[0064] In some embodiments, the process further comprises the step of q) crystallizing nickel sulfate from an acidic aqueous solution containing nickel cations obtained in step h).

[0065] In some embodiments, the process further comprises the step of r) crystallizing lithium sulfate from an acidic aqueous solution containing lithium cations obtained in step k).

[0066] In some embodiments, the process further comprises: s) adjusting the pH of the aqueous solution obtained in step e) to a range of 7 to 8.5 and precipitating a mixed metal hydroxide and / or carbonate (MHP) from the solution; t) performing solid / liquid separation of the mixture obtained in step s) to obtain solid MHP and mother liquor; u) dissolving the solid MHP in sulfuric acid; v) removing residual solid from the solution obtained in step u); w) supplying the solution obtained in step v) to step f); and x) supplying the mother liquor obtained in step t) to step i). The mother liquor obtained in step t) contains lithium, sodium, and magnesium cations that can be recovered from the mother liquor.

[0067] In some embodiments, the process further comprises the step of y) performing solvent extraction of the mother liquor obtained after crystallizing the nickel sulfate in step q) to obtain an aqueous solution depleted of nickel cations and a solvent containing nickel cations, and supplying the solvent containing nickel cations to step g).

[0068] Solvent extraction is performed in step f) using an organic solvent suitable for extracting manganese cations and impurity cations of the group consisting of Ca, Cu, Zn, and Cd from the aqueous solution. In some embodiments, the solvent used in step f) is a dearomatized hydrocarbon fluid (e.g., kerosene, e.g., Exxsol). TM D80 or Escaid TM 110) is a solution of 40 vol% bis(2-ethylhexyl)phosphate (D2EHPA).

[0069] Solvent extraction is performed using an organic solvent suitable for extracting cobalt cations from the aqueous solution in step g). Examples of suitable organic solvents include phosphinic acid derivatives, e.g., bis-(2,4,4-trimethylpentyl)phosphinic acid (Cyanex ® 272) is included. In some embodiments, the solvent used in step g) is a dearomatized hydrocarbon fluid (Escaid) containing 1 g / L of butylhydroxytoluene (BHT). TM 20 vol% of bis-(2,4,4-trimethylpentyl)phosphinic acid (Cyanex) in 110 ® It is a solution of 272).

[0070] Solvent extraction is performed using an organic solvent suitable for extracting nickel cations from the aqueous solution in step h). In some embodiments, the organic solvent used in step h) is a dearomatized hydrocarbon fluid (Escaid) containing 1 g / L of butylhydroxytoluene (BHT). TM 30 vol% of 110) neodecanoic acid (Versatic TM It is a solution of 10).

[0071] Solvent extraction is performed using an organic solvent suitable for extracting lithium cations from an aqueous solution in step k). Examples of suitable organic solvents include synergistic extractant mixtures comprising a beta-diketone and a neutral extractant, e.g., an organophosphate, as disclosed in the literature [J Chem Technol Biotechnol 2016; 91: 2549-2562] (Table 3); [Hydrometallurgy 154 (2015) 33-39]; and [Hydrometallurgy 175 (2018) 35-42]. Further examples of suitable organic solvents include an organic solution comprising an organic diluent, at least one phosphine oxide, and at least one proton donor, as disclosed in WO 2013 / 065050 A1. In some embodiments, the phosphine oxide corresponds to the general formula O=PR1R2R3, where each of R1, R2, and R3 is a straight-chain or branched C1-C 10 Alkyl, straight-chain or branched C2-C 10 Alkenyl, straight-chain or branched C2-C 10 Alkynyl, selectively substituted C5-C 12 Aryl, selectively substituted C4-C 12 The at least one proton donor is independently selected from heteroaryls; and the at least one proton donor is a straight-chain or branched C1-C 10 Alcohol, C1-C 10 Ketone, C1-C 10 Aldehyde, C3-C 20Selected from the group consisting of fatty acids and any combination thereof; the molar ratio between the phosphine oxide and the organic acid in the extracted organic solution is in the range of about 5:1 to about 1:5. In some embodiments, the solvent used in step k) comprises benzoyltrifluoroacetone (HBTA) and tri-n-octylphosphine oxide (TOPO). In some embodiments, the solvent used in step k) comprises tenoyltrifluoroacetone (TTA) and tri-n-octylphosphine oxide (TOPO). In some embodiments, the solvent used in step k) is a dearomatized hydrocarbon fluid (Escaid TM 110) of 27 vol% Cyanex ® It is a solution of 936P.

[0072] The present disclosure also provides a production plant suitable for carrying out the process of the present disclosure. In some embodiments, the production plant includes a first solvent extraction (SX) unit configured to receive an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations. The first SX unit includes an extraction module and a scrubbing and stripping module. In the extraction module of the SX unit, the aqueous solution is extracted with an organic solvent, and an aqueous phase and an organic phase are formed during the process. The organic phase is separated from the aqueous phase and transferred to a scrubbing and stripping module, where it comes into contact with an aqueous acid. After scrubbing and stripping, the organic phase is returned to the extraction module. Suitable solvent extraction (SX) units are known in the art.

[0073] The production plant comprises at least one first continuous stirred tank reactor (CSTR), configured to receive an aqueous effluent from the extraction module of the first SX unit where the first SX unit is present, or alternatively, configured to receive an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations. Where the first SX unit is present, the first CSTR is located downstream of the first SX unit. At least one first CSTR comprises a liquid dosing device, a heating / cooling means, and a gas injection means. Suitable continuous stirred tank reactors are known in the art.

[0074] The production plant further includes at least one first solid / liquid separation unit configured to receive the effluent of the first CSTR. Accordingly, at least one first solid / liquid separation unit is located downstream of the first CSTR. In some embodiments, the first solid / liquid separation unit includes a filter press.

[0075] The production plant also includes at least one second continuous stirred tank reactor (CSTR) configured to receive the aqueous effluent of at least one first solid / liquid separation device. Thus, the second CSTR is located downstream of the first solid / liquid separation device. The first CSTR includes a liquid dosing device and heating / cooling means. Suitable continuous stirred tank reactors are known in the art.

[0076] The production plant additionally includes at least one second solid / liquid separation unit configured to receive the effluent of the second CSTR. Thus, at least one second solid / liquid separation unit is located downstream of the second CSTR. In some embodiments, the first solid / liquid separation unit includes a filter press.

[0077] The production plant further comprises a second solvent extraction (SX) unit configured to receive an aqueous effluent from at least one second solid / liquid separation device. The second SX unit comprises an extraction module and a scrubbing and stripping module. In the extraction module of the SX unit, the aqueous solution is extracted with an organic solvent, and an aqueous phase and an organic phase are formed during the process. The organic phase is separated from the aqueous phase and transferred to a scrubbing and stripping module, where it is extracted with an aqueous acid. After scrubbing and stripping, the organic phase is returned to the extraction module. Suitable solvent extraction (SX) units are known in the art.

[0078] The production plant further comprises a third solvent extraction (SX) unit configured to receive the aqueous effluent from the extraction module of the second SX unit. The third SX unit comprises an extraction module and a scrubbing and stripping module. In the extraction module of the SX unit, the aqueous solution is extracted with an organic solvent, and an aqueous phase and an organic phase are formed during the process. The organic phase is separated from the aqueous phase and transferred to the scrubbing and stripping module, where it is extracted with an aqueous acid. After scrubbing and stripping, the organic phase is returned to the extraction module. Suitable solvent extraction (SX) units are known in the art.

[0079] The production plant further comprises a fourth solvent extraction (SX) unit configured to receive the aqueous effluent from the extraction module of the third SX unit. The fourth SX unit comprises an extraction module and a scrubbing and stripping module. In the extraction module of the SX unit, the aqueous solution is extracted with an organic solvent, and an aqueous phase and an organic phase are formed during the process. The organic phase is separated from the aqueous phase and transferred to the scrubbing and stripping module, where it is extracted with an aqueous acid. After scrubbing and stripping, the organic phase is returned to the extraction module. Suitable solvent extraction (SX) units are known in the art.

[0080] The production plant also includes at least one third continuous stirred tank reactor (CSTR) configured to receive the aqueous effluent from the extraction module of the fourth SX unit. Thus, the third CSTR is located downstream of the fourth SX unit. The third CSTR includes a liquid dosing device and heating / cooling means. Suitable continuous stirred tank reactors are known in the art.

[0081] The production plant additionally includes at least one third solid / liquid separation unit configured to receive the effluent of the third CSTR. Thus, at least one third solid / liquid separation unit is located downstream of the third CSTR. In some embodiments, the third solid / liquid separation unit includes a filter press.

[0082] The production plant further comprises a fifth solvent extraction (SX) unit configured to receive the aqueous effluent of the third solid / liquid separation device. The fifth SX unit comprises an extraction module and a scrubbing and stripping module. In the extraction module of the SX unit, the aqueous solution is extracted with an organic solvent, and an aqueous phase and an organic phase are formed during the process. The organic phase is separated from the aqueous phase and transferred to the scrubbing and stripping module, where it is extracted with an aqueous acid. After scrubbing and stripping, the organic phase is returned to the extraction module. Suitable solvent extraction (SX) units are known in the art.

[0083] The production plant additionally includes at least one fourth continuous stirred tank reactor (CSTR) configured to receive the aqueous effluent from the scrubbing and stripping module of the second SX unit. Thus, the fourth CSTR is located downstream of the second SX unit. The fourth CSTR includes a liquid dosing device and heating / cooling means. Suitable continuous stirred tank reactors are known in the art.

[0084] The production plant additionally includes at least one fourth solid / liquid separation unit configured to receive the effluent of the fourth CSTR. Thus, at least one fourth solid / liquid separation unit is located downstream of the fourth CSTR. In some embodiments, the fourth solid / liquid separation unit includes a filter press.

[0085] The production plant additionally includes at least one fifth continuous stirred tank reactor (CSTR) configured to receive the aqueous effluent of the fourth solid / liquid separation device. Thus, the fifth CSTR is located downstream of the fourth solid / liquid separation device. The fifth CSTR includes a liquid dosing device and heating / cooling means. Suitable continuous stirred tank reactors are known in the art.

[0086] The production plant additionally includes at least one fifth solid / liquid separation unit configured to receive the effluent of the fifth CSTR. Thus, at least one fifth solid / liquid separation unit is located downstream of the fifth CSTR. In some embodiments, the third solid / liquid separation unit includes a filter press.

[0087] The production plant additionally includes a first crystallizer configured to receive the aqueous effluent from the scrubbing and stripping module of the third SX unit and to produce crystals of the first metal salt. Suitable crystallizers are known in the art.

[0088] The production plant additionally includes a second crystallizer configured to receive the aqueous effluent from the scrubbing and stripping module of the fourth SX unit and to produce crystals of the second metal salt. Suitable crystallizers are known in the art.

[0089] The production plant additionally includes a third crystallizer configured to receive the aqueous effluent from the scrubbing and stripping module of the fifth SX unit and to produce crystals of the third metal salt. Suitable crystallizers are known in the art.

[0090] In some embodiments of the production plant, the first solid / liquid separation device, the second solid / liquid separation device, the third solid / liquid separation device, the fourth solid / liquid separation device, and the fifth solid / liquid separation device each include a filter press.

[0091] In some embodiments, the production plant further comprises a sixth continuous stirred tank reactor (CSTR) configured to receive the aqueous effluent of the second solid / liquid separation device. Thus, the sixth CSTR is located downstream of the second solid / liquid separation device. The sixth CSTR includes a liquid dosing device, a heating / cooling means, and a gas injection means. Suitable continuous stirred tank reactors are known in the art.

[0092] In these embodiments, the production plant further includes at least one sixth solid / liquid separation unit configured to receive the effluent of the sixth CSTR. Thus, at least one sixth solid / liquid separation unit is located downstream of the sixth CSTR. In some embodiments, the sixth solid / liquid separation unit includes a filter press.

[0093] In these embodiments, the production plant further comprises a seventh continuous stirred tank reactor (CSTR) configured to receive solid from the sixth solid / liquid separation device. Thus, the seventh CSTR is located downstream of the sixth solid / liquid separation device. The seventh CSTR includes a liquid dosing device, a heating / cooling means, and a gas injection means. Suitable continuous stirred tank reactors are known in the art.

[0094] In these embodiments, the production plant further includes at least one seventh solid / liquid separation device configured to receive the effluent of the seventh CSTR and to transfer the generated mother liquor to the inlet of the second SX unit. Thus, at least one seventh solid / liquid separation device is located downstream of the seventh CSTR and upstream of the second SX unit. In some embodiments, the seventh solid / liquid separation device includes a filter press.

[0095] In some embodiments, the production plant further comprises a sixth solvent extraction (SX) unit configured to receive the aqueous effluent of the second crystallizer. The sixth SX unit comprises an extraction module configured to deliver a stream of organic solvent loaded with metal cations to the organic solvent circuit of the third SX unit and deliver a stream of aqueous effluent to the third CSTR. In the extraction module of the SX unit, the aqueous solution is extracted with the organic solvent, and an aqueous phase and an organic phase are formed during the process. The organic phase is separated from the aqueous phase and transferred to the organic solvent circuit of the third SX unit. The aqueous phase, depleted of metal cations, is transferred to the third CSTR. Suitable solvent extraction (SX) units are known in the art.

[0096] Detailed description of the drawing

[0097] A schematic diagram of an exemplary production plant of the present disclosure is shown in FIG. 1.

[0098] The production plant includes a first solvent extraction (SX) unit (10) configured to receive an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations (1000). The first SX unit (10) includes an extraction module (11) and a scrubbing and stripping module (12). The acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations introduced into the first SX unit (10) is extracted with an organic solvent in the extraction module (11). The extracted aqueous phase leaves the extraction module (11) as an aqueous effluent (1001). The loaded organic phase is transferred to the scrubbing and stripping module (12), where the metal cations are scrubbed and stripped with sulfuric acid to produce an acidic aqueous solution containing metal cations from the organic phase. The organic phase is recycled to the extraction module (11), and the acidic aqueous solution containing metal cations from the organic phase leaves the scrubbing and stripping module (12) as an aqueous effluent (1002). In an exemplary process, copper cations are extracted from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations (1000) in the first solvent extraction (SX) unit (10) and transferred to the aqueous effluent (1002). From the aqueous effluent (1002), metallic copper can be recovered, for example, by electro-extraction.

[0099] The production plant further comprises a first continuous stirred tank reactor (CSTR) (70) configured to receive the aqueous effluent (1001) of the extraction module (11) of the first SX unit (10). The CSTR (70) comprises a liquid dispensing device, a heating / cooling means, and a gas injection means. In the CSTR (70), a solution containing sodium carbonate is added to precipitate impurity anions, including P, F, or Si, and impurity cations of the group consisting of Al and Fe cations present in the solution. Air is injected into the mixture to oxidize any present Fe(II) to Fe(III) and to maximize the precipitation of iron from the liquid phase.

[0100] The production plant additionally includes at least one first solid / liquid separation device (140) configured to receive the effluent (7001) of the first CSTR (70). In at least one first solid / liquid separation device (140), metal salts (14002) of impurity cations in a group consisting of impurity anions including P, F, or Si present in the solution and Al and Fe cations are recovered from the effluent of the first CSTR (70) by solid / liquid separation, e.g., filtration. The solid (14002) is usually discarded.

[0101] The production plant additionally includes a second continuous stirred tank reactor (CSTR) (80) configured to receive the aqueous effluent (14001) of the first solid / liquid separation device (140). The CSTR (80) includes a liquid dispensing device and a heating / cooling means. In the CSTR (80), a solution containing sodium carbonate is added to precipitate additional impurity cations from the solution, consisting of a group of Al and Fe cations, and impurity anions including P, F, or Si present in the solution.

[0102] The production plant further comprises at least one second solid / liquid separation device (150) configured to receive the effluent (8001) of the second CSTR (80). In at least one second solid / liquid separation device (150), metal salts (15002) of impurity cations in a group consisting of Al and Fe cations and impurity anions including P, F, or Si present in the solution are recovered from the effluent of the second CSTR (80) by solid / liquid separation, e.g., filtration. Since the solid (15002) may contain a significant amount of valuable metals such as nickel and cobalt, they may be recycled to a leaching step to produce an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations (1000).

[0103] The production plant further includes a second solvent extraction (SX) unit (20) configured to receive the aqueous effluent (15001) of the second solid / liquid separation device (150). The second SX unit (20) includes an extraction module (21) and a scrubbing and stripping module (22). In the extraction module (21), the aqueous effluent (15001) flowing into the second SX unit (20) is extracted with an organic solvent. The extracted aqueous phase exits the extraction module (21) as the aqueous effluent (2001). The loaded organic phase is transferred to the scrubbing and stripping module (22), where metal cations are scrubbed and stripped with sulfuric acid to produce an acidic aqueous solution containing metal cations from the organic phase. The organic phase is recycled to the extraction module (21), and the acidic aqueous solution containing metal cations from the organic phase exits the scrubbing and stripping module (22) as an aqueous effluent (2002).

[0104] The production plant further comprises a third solvent extraction (SX) unit (30) configured to receive the aqueous effluent (2001) of the extraction module (21) of the second SX unit (20). The third SX unit (30) comprises an extraction module (31) and a scrubbing and stripping module (32). The aqueous effluent (2001) entering the third SX unit (30) is extracted with an organic solvent in the extraction module (31). The extracted aqueous phase leaves the extraction module (31) as the aqueous effluent (3001). The loaded organic phase is transferred to the scrubbing and stripping module (32), where it is scrubbed and stripped with sulfuric acid to produce an acidic aqueous solution containing metal cations from the organic phase. The organic phase is recycled to the extraction module (31), and the acidic aqueous solution containing metal cations from the organic phase leaves the scrubbing and stripping module (32) as an aqueous effluent (3002).

[0105] The production plant further includes a fourth solvent extraction (SX) unit (40) configured to receive the aqueous effluent (3001) of the extraction module (31) of the third SX unit (30). The fourth SX unit (40) includes an extraction module (41) and a scrubbing and stripping module (42). The aqueous effluent (3001) flowing into the fourth SX unit (40) is extracted with an organic solvent in the extraction module (41). The extracted aqueous phase leaves the extraction module (41) as the aqueous effluent (4001). The loaded organic phase is transferred to the scrubbing and stripping module (42), where metal cations are scrubbed and stripped with sulfuric acid to produce an acidic aqueous solution containing metal cations from the organic phase. The organic phase is recycled to the extraction module (41), and the acidic aqueous solution containing metal cations from the organic phase leaves the scrubbing and stripping module (42) as an aqueous effluent (4002).

[0106] The production plant further includes a third continuous stirred tank reactor (CSTR) (90) configured to receive the aqueous effluent (4001) of the extraction module (41) of the fourth SX unit (40). The CSTR (90) includes a liquid dispensing device and a heating / cooling means. In the CSTR (90), a solution containing sodium hydroxide is added to precipitate magnesium hydroxide.

[0107] The production plant further comprises at least one third solid / liquid separation device (160) configured to receive the effluent (9001) of the third CSTR (90). In the at least one third solid / liquid separation device (160), magnesium hydroxide (16002) is recovered from the effluent of the third CSTR (90) by solid / liquid separation, e.g., filtration.

[0108] The production plant further comprises a fifth solvent extraction (SX) unit (50) configured to receive the aqueous effluent (16001) of the third solid / liquid separation device (160). The fifth SX unit (50) comprises an extraction module (51) and a scrubbing and stripping module (52). The aqueous effluent (16001) entering the fifth SX unit (50) is extracted with an organic solvent in the extraction module (51). The extracted aqueous phase leaves the extraction module (51) as the aqueous effluent (5001). The loaded organic phase is transferred to the scrubbing and stripping module (52), where metal cations are scrubbed and stripped with sulfuric acid to produce an acidic aqueous solution containing metal cations from the organic phase. The organic phase is recycled to the extraction module (51), and the acidic aqueous solution containing metal cations from the organic phase leaves the scrubbing and stripping module (52) as an aqueous effluent (5002).

[0109] The production plant further comprises a fourth CSTR (100) configured to receive an aqueous effluent (2002) from the scrubbing and stripping module (22) of the second SX unit (20). The fourth CSTR (100) comprises a liquid dosing device, a heating / cooling means, and a gas injection means. In the fourth CSTR (100), an alkaline solution is added to precipitate manganese carbonate and / or manganese hydroxide.

[0110] The production plant further comprises at least one fourth solid / liquid separation device (170) configured to receive the effluent (10001) of the fourth CSTR (100). In the at least one fourth solid / liquid separation device (170), manganese carbonate and / or manganese hydroxide (17002) are recovered from the effluent (10001) of the fourth CSTR (100) by solid / liquid separation, e.g., filtration.

[0111] The production plant further includes a fifth CSTR (110) configured to receive an aqueous effluent (17001) from a fourth solid / liquid separation device (170). The fifth CSTR (110) includes a liquid dispensing device and a heating / cooling means. In the fifth CSTR (110), an alkaline solution is added to precipitate metal hydroxide.

[0112] The production plant further comprises at least one fifth solid / liquid separation device (180) configured to receive the effluent (11001) of the fifth CSTR (110). In the at least one fifth solid / liquid separation device (180), a metal hydroxide (18002) is recovered from the effluent (11001) of the fifth CSTR (110) by solid / liquid separation, e.g., filtration.

[0113] The production plant additionally includes a first crystallizer (210) configured to receive the aqueous effluent (3002) of the scrubbing and stripping module (32) of the third SX unit (30) and to produce crystals of the first metal salt, for example, cobalt sulfate.

[0114] The production plant further includes a second crystallizer (220) configured to receive the aqueous effluent (4002) of the scrubbing and stripping module (42) of the fourth SX unit (40) and to produce crystals of the second metal salt, for example, nickel sulfate.

[0115] The production plant further includes a third crystallizer (230) configured to receive the aqueous effluent (5002) of the scrubbing and stripping module (52) of the fifth SX unit (50) and to produce crystals of a third metal salt, for example, lithium sulfate.

[0116] The production plant further includes a sixth SX unit (60) configured to receive an aqueous effluent (4003) from a second crystallizer (220). The sixth SX unit (60) includes an extraction module (61) configured to transfer a stream of organic solvent loaded with metal cations (6002) to the organic solvent circuit of a third SX unit (30) and to transfer an aqueous effluent stream (6001) to a third CSTR (90). The aqueous effluent (4003) from the second crystallizer (220) is extracted into an organic solvent in the extraction module (61). The extracted aqueous phase leaves the extraction module (61) as an aqueous effluent (6001) and is transferred to the third CSTR (90). The loaded organic phase leaves the extraction module (61) as an organic effluent (6002) and is recirculated to the organic solvent circuit of the third SX unit (30).

[0117] FIG. 2 illustrates a section of another exemplary production plant of the present disclosure. In an embodiment of this production plant, the section illustrated in FIG. 2 is added to the production plant illustrated in FIG. 1. The dashed line in FIG. 2 indicates the boundary between the production plant illustrated in FIG. 1 and the section.

[0118] In this embodiment, the production plant further comprises a sixth CSTR (120) configured to receive the aqueous effluent (15001) of the second solid / liquid separation device (150). The sixth CSTR (120) comprises a liquid dosing device, a heating / cooling means, and a gas injection means. In the sixth CSTR (120), an alkaline solution is added to precipitate mixed metal hydroxide (MHP).

[0119] The production plant further comprises at least one sixth solid / liquid separation device (190) configured to receive the effluent (12001) of the sixth CSTR (120). In at least one sixth solid / liquid separation device (190), a mixed metal hydroxide (19002) is recovered from the effluent (12001) of the sixth CSTR (120) by solid / liquid separation, e.g., filtration. A mother liquor (19001) containing lithium, sodium, and magnesium cations may be supplied to the third CSTR (90).

[0120] The production plant further comprises a seventh CSTR (130) configured to receive a solid (19002) from at least one sixth solid / liquid separation device (190). The seventh CSTR (130) comprises a liquid dispensing device, a heating / cooling means, and a gas injection means. In the seventh CSTR (130), sulfuric acid is added to dissolve the mixed metal hydroxide (19002).

[0121] The production plant further comprises at least one seventh solid / liquid separation device (200) configured to receive the effluent (13001) of the seventh CSTR (130). In the at least one seventh solid / liquid separation device (200), any solid remaining in the effluent (13001) of the seventh CSTR (130) is removed by solid / liquid separation, for example, by filtration. The aqueous effluent (20001) of the at least one seventh solid / liquid separation device (200) is transferred to the inlet of the extraction module (21) of the second SX unit (20).

[0122] Examples

[0123] Example 1 2-stage impurity precipitation

[0124] A pregnant leach solution (PLS) having the composition as shown in Table 1 (feed solution) was supplied to the first CSTR, and its pH was adjusted to a value of 3.1 to 3.4 at 80°C by adding an alkaline solution containing 250 g / l Na2CO3. The formed precipitate was removed by filtration in a subsequent filter unit, and the filtrate was supplied to the second CSTR, and its pH was adjusted to a value of 4.5 to 4.8 at 80°C by adding an alkaline solution containing 250 g / l Na2CO3. The formed precipitate was removed by filtration in a subsequent filter unit and recirculated to the first CSTR. The obtained filtrate had the composition shown in Table 1 (final solution). The metal loss observed in the first precipitation step (pH = 3.4) was Ni 3.3%, Li 1.5%, Co 0.3%, and Mn 0%.

[0125] Table 1

[0126]

[0127] Example 2 Solvent extraction

[0128] a) Cu SX

[0129] A feed solution containing 3.535 g / l Cu, 5.596 g / l Li, 9.942 g / l Mn, 7.433 g / l Co, and 32.075 g / l Ni was supplied to the first SX unit. Copper cations were extracted using 25 wt% LIX984 in Exxsol D80 as the extractant. The ratio of the organic phase to the aqueous phase (O:A) was 1.1:1. The aqueous feed had a pH of 1.5 and a temperature of 40°C. The loss of Li was less than the detection limit (i.e., <1 mg / kg). The extraction efficiency for copper was 99.2%. The organic phase was scrubbed in an O:A ratio of 30-50:1 with a CuSO4 solution containing 3.4 g / L Cu and a pH of 0.8. Stripping of the organic phase was performed at an O:A ratio of 2:1 using an aqueous feed solution containing 27 g / L Cu in 190 g / L H2SO4 and having a pH of <0. The stripping efficiency was 90%; the total Li loss was 2 mg / L (0.04%).

[0130] b) Mn / Impurity SX

[0131] The aqueous effluent from the first SX unit was fed to the impurity precipitation process. The resulting filtrate, containing 5.918 g / l Li, 11.513 g / l Mn, 8.555 g / l Co, and 32.343 g / l Ni, was fed to the second SX unit. Impurity cations were extracted using 40 wt% D2EHPA in Exxsol D80 as the extractant. The ratio of the organic phase to the aqueous phase (O:A) was 1.85–2:1. The saponification degree of the organic extractant was 50%. The aqueous feed had a pH of 3.5 and a temperature of 40°C. The Li loss was 310 mg / kg (5.24%), and the extraction efficiency for manganese was >99%. The organic phase was scrubbed with 90–200 g / L H2SO4 at a pH of 1.6–2.0 and an O:A ratio of 30–50:1. The scrubbing efficiency was 99.6% for Co, 97% for Li, 94.8% for Mn, 97% for Na, and 100% for Ni. Stripping of the organic phase was performed at an O:A ratio of 1.3–2:1 using an aqueous feed solution containing 50 g / L H2SO4 and having a pH of 0.8. The stripping efficiency was 100%, and the total Li loss reached 9 mg / L (0.15%).

[0132] c) Co SX

[0133] An aqueous effluent from the second SX unit containing 5.014 g / l Li, 6.796 g / l Co, and 27.979 g / l Ni was fed to the third SX unit. Cobalt cations were extracted using 17.5–22.5 wt% Cyanex 272 in Exxsol D80 as the extractant. The organic phase to aqueous phase ratio (O:A) was 1.4–2.0:1. The degree of saponification of the organic extractant was 30%. The pH of the aqueous feed was 4.2–6 and the temperature was 48–53°C. The Li loss was 323 mg / kg (6.44%), and the extraction efficiency for cobalt was 99.7%. The organic phase was scrubbed with an acidic aqueous solution having a pH of 3.7 at an O:A ratio of 30:1. Stripping of the organic phase was performed using an aqueous feed solution containing 165 g / L H2SO4 at pH 1.5 and an O:A ratio of 18.5:1. The stripping efficiency was >99.5%, and the total Li loss was < 1 ppm.

[0134] d)Ni SX

[0135] An aqueous effluent from the third SX unit containing 5.045 g / l Li and 26.926 g / l Ni was fed to the fourth SX unit. Nickel cations were extracted using 27-33 wt% Versatic 10 in Exxsol D80 as the extractant. The ratio of the organic phase to the aqueous phase (O:A) was 2:1. The degree of saponification of the organic extractant ranged from 10 to 47%. The aqueous feed had a pH of 6.7 and a temperature of 40-55°C. The extraction efficiency for nickel was 99.9%. The organic phase was scrubbed with diluted sulfuric acid at a pH of 5.3 and an O:A ratio of 1:1. The scrubbing efficiency for Li was 99.6%. Stripping of the organic phase was performed using an aqueous feed solution containing 20% ​​H2SO4 at a pH of 1.8. The total Li loss was 2 mg / kg (0.43%).

[0136] e) Li SX

[0137] The aqueous effluent from Unit 4 SX was fed to Unit 5 SX. Lithium cations were extracted using 40 wt% Cyanex 936P in Exxsol D80 as the extractant. The ratio of the organic phase to the aqueous phase (O:A) was 0.75:1. The aqueous feed had a pH of 12–13 and a temperature of 30–35°C. The organic phase was scrubbed in an O:A ratio of 20:1. Stripping of the organic phase was performed using diluted H2SO4 at pH 2.5.

[0138] Example 3 Data of an exemplary production plant

[0139] For an exemplary production plant, Table 2 shows the feed composition for producing an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations from lithium-ion battery material. Both the mass fractions of individual elements in the feed and the total annual mass supplied to the production plant are listed. Table 3 lists the annual amounts of some products obtained from the production plant. Table 4 shows the composition of the liquid effluent from the impurity precipitation stage of the production plant. 483.39 tons / day of liquid effluent is produced. Table 5 shows the composition of the filter cake from the Mg precipitation stage of the production plant. 0.51 tons / day of solid is produced. Table 6 shows the composition of the liquid effluent from the Li solvent extraction stage of the production plant. 2040.08 tons / day of liquid effluent is produced.

[0140] Table 2

[0141]

[0142] Table 3

[0143]

[0144] Table 4

[0145]

[0146] Table 5

[0147]

[0148] Table 6

[0149] Explanation of the symbols

[0150] List of drawing reference numbers 10 1st SX Unit 11 Extraction module of the 1st SX unit 12 Scrubbing and stripping module of the 1st SX unit 20 2nd SX Unit 21 Extraction module of the 2nd SX unit 22 Scrubbing and stripping module of the 2nd SX unit 30 3rd SX Unit 31 Extraction module of the 3rd SX unit 32 Scrubbing and stripping module of the 3rd SX unit 40 4th SX Unit 41 Extraction module of the 4th SX unit 42 Scrubbing and stripping module of the 4th SX unit 50 5th SX Unit 51 Extraction module of the 5th SX unit 52 Scrubbing and stripping module of the 5th SX unit 60 6th SX Unit 61 Extraction module of the 6th SX unit 70 1st CSTR 80 2nd CSTR 90 3rd CSTR 100 4th CSTR 110 5th CSTR 120 6th CSTR 130 7th CSTR 140 1st Solid / Liquid Separation Unit 150 2nd Solid / Liquid Separation Unit 160 3rd Solid / Liquid Separation Unit 170 4th Solid / Liquid Separation Unit 180 5th Solid / Liquid Separation Unit 190 6th Solid / Liquid Separation Unit 200 7th Solid / Liquid Separation Unit 210 First crystallizer 220 Second crystallizer 230 Third crystallizer 1000 Acidic aqueous solution containing Ni, Co, Mn, and Li cations 1001 Aqueous effluent from the extraction module of the 1st SX unit 1002 Aqueous effluent (Cu) from the scrubbing and stripping module of the 1st SX unit 2001 Aqueous effluent from the extraction module of the 2nd SX unit 2002 Aqueous effluent from the scrubbing and stripping module of the 2nd SX unit 3001 Aqueous effluent from the extraction module of the 3rd SX unit 3002 Aqueous effluent from the scrubbing and stripping module of the 3rd SX unit 4001 Aqueous effluent from the extraction module of the 4th SX Unit 4002 Aqueous effluent from the scrubbing and stripping module of the 4th SX unit 4003 Aqueous effluent from the second crystallization unit 5001 Aqueous effluent from the extraction module of the 5th SX Unit 5002 Aqueous effluent from the scrubbing and stripping module of Unit 5 SX 6001 Aqueous effluent from the extraction module of the 6th SX Unit 6002 Organic effluent from the extraction module of the 6th SX unit 7001 effluent from the 1st CSTR 8001 2nd CSTR effluent 9001 effluent from the 3rd CSTR 10001 effluent from the 4th CSTR 11001 effluent from the 5th CSTR 12001 effluent from CSTR 6 13001 effluent from CSTR 7 14001 Aqueous effluent from the first solid / liquid separation unit 14002 Solid (impurity salt) 15001 Aqueous effluent from the 2nd solid / liquid separation unit 15002 Solid (impurity salt) 16001 Aqueous effluent from the 3rd solid / liquid separation unit 16002 Solid (magnesium hydroxide) 17001 Aqueous effluent from the 4th solid / liquid separation unit 17002 Solid (manganese hydroxide and / or carbonate) 18001 Aqueous effluent of the 5th Solid / Liquid Separation Unit 18002 Solid (metal hydroxide) 19001 Aqueous effluent of the 6th Solid / Liquid Separation Unit 19002 Solid (MHP) 20001 Aqueous effluent of the 7th Solid / Liquid Separation Unit 20002 Solid (Insoluble Residue)

Claims

Claim 1 A continuous process for recovering a metal salt from an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations, comprising: a) optionally adjusting the pH value of the solution to a value within the range of 1.5 to 2.5 and recovering copper from the solution by solvent extraction or by solid / liquid separation after precipitation of copper sulfide; b) adjusting the pH of the acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations to a range of 3.0 to 4.0 by adding sodium carbonate, and subsequently precipitating impurity cations of the group consisting of Al and Fe cations and impurity anions including P, F, Al, and / or Si present in the solution from the solution; c) removing the solid from the mixture obtained in step b); and d) adjusting the pH of the acidic aqueous solution obtained in step c) to 4.5 to 5 by adding sodium carbonate.a) adjusting to a range of 0, and then precipitating impurity cations of the group consisting of Al and Fe cations present in the solution and impurity anions including P, F, Al and / or Si from the solution; e) removing the solid from the mixture obtained in step d); f) adjusting the pH of the acidic aqueous solution obtained in step e) to a range of 2 to 4, and then removing any residual impurity cations of the group consisting of manganese cations and Ca, Cu, Zn and Cd cations present in the solution by solvent extraction to obtain an aqueous solution depleted of manganese cations and impurity cations and a solvent containing manganese cations and impurity cations; scrubbing and stripping the solvent containing manganese cations and impurity cations with sulfuric acid to obtain an acidic aqueous solution containing manganese cations and impurity cations; g) adjusting the pH of the aqueous solution depleted of manganese cations and impurity cations obtained in step f) to a range of 3 to 6; Subsequently, the cobalt cation is removed from the solution by solvent extraction to obtain an aqueous solution depleted of cobalt cations and a solvent containing cobalt cations; the solvent containing cobalt cations is scrubbed and stripped with sulfuric acid to obtain an acidic aqueous solution containing cobalt cations, step h) adjusting the pH of the aqueous solution depleted of cobalt cations obtained in step g) to a range of 5 to 7.5; subsequently, the nickel cation is removed from the solution by solvent extraction to obtain an aqueous solution depleted of nickel cations and a solvent containing nickel cations; the solvent containing nickel cations is scrubbed and stripped with sulfuric acid to obtain an acidic aqueous solution containing nickel cations, step i) adding sodium hydroxide to the aqueous solution depleted of nickel cations obtained in step h) to adjust the pH to 10 to 12.A process comprising the steps of: adjusting the pH to a range of 5 and precipitating magnesium hydroxide from the solution; j) removing a solid from the mixture obtained in step i); k) adjusting the pH of the aqueous solution obtained in step j) to a range of 8 to 12, and then removing lithium cations from the solution by solvent extraction to obtain an aqueous solution depleted of lithium cations and a solvent containing lithium cations; and scrubbing and stripping the solvent containing lithium cations with sulfuric acid to obtain an acidic aqueous solution containing lithium cations. Claim 2 A process according to claim 1, further comprising: l) a step of adjusting the pH of an acidic aqueous solution containing manganese cations and impurity cations obtained in step f) to a range of 6.8 to 8.5 and precipitating manganese carbonate and / or manganese hydroxide from the solution; m) a step of removing a solid from the mixture obtained in step l); n) optionally, a step of adjusting the pH of the solution obtained in step l) to a range of 10 to 12.5 and precipitating a metal hydroxide from the solution; and o) optionally, a step of removing a solid from the mixture obtained in step n). Claim 3 A process according to claim 1 or 2, further comprising the step of crystallizing cobalt sulfate from an acidic aqueous solution containing a cobalt cation obtained in step g). Claim 4 A process according to any one of claims 1 to 3, further comprising the step of crystallizing nickel sulfate from an acidic aqueous solution containing nickel cations obtained in step h). Claim 5 A process according to any one of claims 1 to 4, further comprising the step of crystallizing lithium sulfate from an acidic aqueous solution containing lithium cations obtained in step k). Claim 6 A process according to any one of claims 1 to 5, further comprising: s) adjusting the pH of the aqueous solution obtained in step e) to be in the range of 7 to 8.5 and precipitating the mixed metal hydroxide and / or mixed metal carbonate from the solution; t) performing solid / liquid separation of the mixture obtained in step s) to obtain the solid mixed metal hydroxide and / or mixed metal carbonate and the mother liquor; u) dissolving the solid mixed metal hydroxide and / or mixed metal carbonate obtained in step t) in sulfuric acid; v) removing the residual solid from the solution obtained in step u); w) supplying the solution obtained in step v) to step f); and x) supplying the mother liquor obtained in step t) to step i). Claim 7 A process according to any one of claims 4 to 6, further comprising the step of y) performing solvent extraction of the mother liquor obtained after crystallizing nickel sulfate in step q) to obtain an aqueous solution depleted of nickel cations and a solvent containing nickel cations; and supplying the solvent containing nickel cations to step g). Claim 8 A process according to any one of claims 1 to 7, wherein the solvent used in step f) is a solution of 40 vol% bis(2-ethylhexyl)phosphate in a dearomaticated hydrocarbon fluid. Claim 9 A process according to any one of claims 1 to 8, wherein the solvent used in step g) is a solution of 20 vol% bis-(2,4,4-trimethylpentyl)phosphinic acid in a dearomaticized hydrocarbon fluid containing 1 g / L butylhydroxytoluene. Claim 10 A process according to any one of claims 1 to 9, wherein the solvent used in step h) is a solution of 30 vol% neodecanoic acid in a dearomatized hydrocarbon fluid containing 1 g / L butylhydroxytoluene. Claim 11 A production plant comprising the following: (1) a first solvent extraction (SX) unit (10) configured to receive an acidic aqueous solution containing nickel, cobalt, manganese, and lithium cations (1000), i) extraction module (11), ii) a first SX unit (10) comprising a scrubbing and stripping module (12); (2) at least one first continuous stirred tank reactor (CSTR) (70) configured to receive the aqueous effluent (1001) of the extraction module (11) of the first SX unit (10), i) liquid dosing device, ii) Heating / cooling means, iii) a first continuous stirred tank reactor (CSTR) (70) comprising a gas injection means; (3) at least one first solid / liquid separation device (140) configured to receive the effluent (7001) of the first CSTR (70); (4) at least one second continuous stirred tank reactor (CSTR) (80) configured to receive the effluent (14001) of the first solid / liquid separation device (140), wherein i) Liquid dispensing device, ii) a second continuous stirred tank reactor (CSTR) (80) including a heating / cooling means; (5) at least one second solid / liquid separation device (150) configured to receive the effluent (8001) of the second CSTR (80); (6) a second solvent extraction (SX) unit (20) configured to receive the aqueous effluent (15001) of the second solid / liquid separation device (150), wherein i) extraction module (21), ii) a second solvent extraction (SX) unit (20) comprising a scrubbing and stripping module (22); (7) a third solvent extraction (SX) unit (30) configured to receive an aqueous effluent (2001) from an extraction module (21) of the second SX unit (20), i) extraction module (31), ii) a third solvent extraction (SX) unit (30) comprising a scrubbing and stripping module (32); (8) a fourth solvent extraction (SX) unit (40) configured to receive an aqueous effluent (3001) from an extraction module (31) of the third SX unit (30), i) extraction module (41), ii) a fourth solvent extraction (SX) unit (40) comprising a scrubbing and stripping module (42); (9) at least one third continuous stirred tank reactor (CSTR) (90) configured to receive an aqueous effluent (4001) from an extraction module (41) of the fourth SX unit (40), i) Liquid dispensing device, ii) a third continuous stirred tank reactor (CSTR) (90) comprising a heating / cooling means; (10) at least one third solid / liquid separation device (160) configured to receive the effluent (9001) of the third CSTR (90); (11) a fifth solvent extraction (SX) unit (50) configured to receive the aqueous effluent (16001) of the third solid / liquid separation device (160), wherein i) extraction module (51), ii) a fifth solvent extraction (SX) unit (50) comprising a scrubbing and stripping module (52); (12) at least one fourth continuous stirred tank reactor (CSTR) (100) configured to receive an aqueous effluent (2002) from the scrubbing and stripping module (22) of the second SX unit (20), i) Liquid dispensing device, ii) Heating / cooling means, iii) a fourth continuous stirred tank reactor (CSTR) (100) including a gas injection means; (13) at least one fourth solid / liquid separation device (170) configured to receive the effluent (10001) of the fourth CSTR (100); (14) at least one fifth continuous stirred tank reactor (CSTR) (110) configured to receive the effluent (17001) of the fourth solid / liquid separation device (170), i) Liquid dispensing device, ii) a fifth continuous stirred tank reactor (CSTR) (110) comprising a heating / cooling means; (15) at least one fifth solid / liquid separation device (180) configured to receive the effluent (11001) of the fifth CSTR (110); (16) a first crystallizer (210) configured to receive the aqueous effluent (3002) of the scrubbing and stripping module (32) of the third SX unit (30) and to produce crystals of the first metal salt; (17) a second crystallizer (220) configured to receive the aqueous effluent (4002) of the scrubbing and stripping module (42) of the fourth SX unit (40) and to produce crystals of the second metal salt; (18) a third crystallizer (230) configured to receive the aqueous effluent (5002) of the scrubbing and stripping module (52) of the fifth SX unit (50) and to produce crystals of the third metal salt. Production plant. Claim 12 In claim 11, the first solid / liquid separation device (140), the second solid / liquid separation device (150), the third solid / liquid separation device (160), the fourth solid / liquid separation device (170), and the fifth solid / liquid separation device (180) each comprise a filter press, in a production plant. Claim 13 In claim 11 or 12, (19) at least one sixth continuous stirred tank reactor (CSTR) (120) configured to receive the aqueous effluent (15001) of the second solid / liquid separation device (150), i) Liquid dispensing device, ii) Heating / cooling means, iii) a sixth continuous stirred tank reactor (CSTR) (120), (20) comprising a gas injection means; at least one sixth solid / liquid separation device (190), (21) configured to receive the effluent (12001) of the sixth CSTR (120); and at least one seventh continuous stirred tank reactor (CSTR) (130) configured to receive the solid (19002) from the sixth solid / liquid separation device (190). i) Liquid dispensing device, ii) Heating / cooling means, iii) A production plant further comprising at least one seventh solid / liquid separation device (200) configured to receive the effluent (13001) of the seventh continuous stirred tank reactor (CSTR) (130), (22) including a gas injection means, and configured to transfer the generated mother liquor (20001) to the inlet of the extraction module (21) of the second SX unit (20). Claim 14 A production plant further comprising, in any one of claims 11 to 13, a sixth solvent extraction (SX) unit (60) configured to receive an aqueous effluent (4003) of a second crystallizer (220), and comprising an extraction module (61) configured to deliver a stream (6002) of a metal cation-loaded organic solvent to the solvent circuit of a third SX unit (30) and deliver an aqueous effluent stream (6001) to a third CSTR (90).

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