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CA-3185166-C - METHOD FOR SEPARATING AND RECOVERING COBALT SALT AND NICKEL SALT

CA3185166CCA 3185166 CCA3185166 CCA 3185166CCA-3185166-C

Abstract

The present invention relates to a method for separating and recovering a cobalt salt and a nickel salt, the method including a separation step for separating a cobalt salt and a nickel salt from a rare metal-containing aqueous solution that contains at least a cobalt salt and a nickel salt as rare metals by means of a nanofiltration membrane. The nanofiltration membrane is such that the glucose permeability is at least 3 times the sucrose permeability, the sucrose permeability is 10% or less and the isopropyl alcohol permeability is 50% or more, when a 1000 mg/L aqueous glucose solution having a pH of 6.5, a 1000 mg/L aqueous sucrose solution, and a 1000 mg/L aqueous solution of isopropyl alcohol are passed through the filter at an operating pressure of 0.5 MPa and a temperature of 25°C.

Inventors

  • Tomoya YOSHIZAKI
  • Takanori SOYA
  • Masakazu Koiwa
  • Shigehisa Hanada

Assignees

  • TORAY INDUSTRIES, INC.

Dates

Publication Date
20260505
Application Date
20210528
Priority Date
20200529

Claims (14)

  1. CLAIMS: 1. A method for separating and recovering a cobalt salt and a nickel salt, the method comprising a separation step of separating, by using a nanofiltration membrane, a cobalt salt and a nickel salt from a rare metal-containing aqueous solution containing at least 5 both the cobalt salt and the nickel salt as rare metals, wherein the nanofiltration membrane has a glucose permeability of 3 times or more a sucrose permeability, the sucrose permeability of 10% or less, and an isopropyl alcohol permeability of 50% or more when a 1,000 mg/L glucose aqueous solution, a 1,000 mg/L sucrose 10 aqueous solution, and a 1,000 mg/L isopropyl alcohol aqueous solution, each having a pH of 6.5 and a temperature of 25°C, individually permeate through the nanofiltration membrane at an operating pressure of 0.5 Mpa, the method further comprises a complex forming step of adding a complex forming agent to the rare metal-containing aqueous solution before the separation step, and 15 the complex forming step comprises a step of adding an amine-based ligand, which is ammonia or ethylenediamine, as the complex forming agent.
  2. 2. The method for separating and recovering a cobalt salt and a nickel salt according to claim 1, wherein the nanofiltration membrane comprises a base material, a support membrane on 20 the base material, and a separation function layer on the support membrane, and the separation function layer comprises a polyamide having a structure derived from a polyfunctional aliphatic amine and a structure derived from a polyfunctional acid halide.
  3. 3. The method for separating and recovering a cobalt salt and a nickel salt according to 25 claim 1 or 2, wherein the complex forming agent has a solubility in water of 100 mg/L or more.
  4. 4. The method for separating and recovering a cobalt salt and a nickel salt according to claim 3, wherein the complex forming step comprises a step of adjusting a pH of the rare metalcontaining aqueous solution to 1 or more and 9 or less.
  5. 5. The method for separating and recovering a cobalt salt and a nickel salt according to any one of claims 1 to 4, further comprising, before the separation step, an acid treatment step of bringing a material containing at least both cobalt and nickel as rare metals into contact with an 90239912 51 acid aqueous solution to obtain the rare metal-containing aqueous solution.
  6. 6. The method for separating and recovering a cobalt salt and a nickel salt according to any one of claims 1 to 5, wherein the separation step comprises at least a first separation step and a 2a-th separation step which use the nanofiltration 5 membrane, and a permeated water obtained in the first separation step is treated in the 2a-th separation step.
  7. 7. The method for separating and recovering a cobalt salt and a nickel salt according to 10 any one of claims 1 to 5, wherein the separation step comprises at least a first separation step and a 2b-th separation step which use the nanofiltration membrane, and a non-permeated water obtained in the first separation step is treated in the 2b-th separation step. 15
  8. 8. The method for separating and recovering a cobalt salt and a nickel salt according to claim 7, wherein the non-permeated water obtained in the first separation step is diluted to be treated in the 2b-th separation step.
  9. 9. The method for separating and recovering a cobalt salt and a nickel salt according to 20 claim 6, wherein the permeated water obtained in the first separation step is diluted to be treated in the 2a-th separation step.
  10. 10. The method for separating and recovering a cobalt salt and a nickel salt according to any one of claims 1 to 9, further comprising, before the separation step, a pre-separation step of 25 separating an alkali metal salt and a polyvalent rare metal salt by using the nanofiltration membrane, to obtain a permeated water in which an alkali metal ion concentration (mg/L) is 100 times or more a polyvalent rare metal ion concentration (mg/L).
  11. 11. The method for separating and recovering a cobalt salt and a nickel salt according to 30 any one of claims 1 to 10, further comprising a concentration step of concentrating an aqueous solution obtained in the separation step with a reverse osmosis membrane. 90239912 52
  12. 12. The method for separating and recovering a cobalt salt and a nickel salt according to claim 5, further comprising a mixing step of mixing a permeated water generated in a concentration step with the rare metal-containing aqueous solution obtained in the acid treatment step, wherein in the separation step, the permeated water and a 5 concentrated water are obtained from a mixed water obtained in the mixing step.
  13. 13. The method for separating and recovering a cobalt salt and a nickel salt according to claim 2, wherein the polyfunctional aliphatic amine is a compound represented by the following 10 general formula (1), [Chem. 1] provided that R1 and R2 each independently represent an alkyl group having 1 to 6 carbon atoms, a phenyl group, a benzyl group, COOR5, CONHR5, CON(R5)2, or OR5, and R5 15 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a benzyl group; and R3 and R4 each independently represent hydrogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, a benzyl group, COOR6, CONHR6, CON(R6)2, or OR6, and R6 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a benzyl group.
  14. 14. The method for separating and recovering a cobalt salt and a nickel salt according to claim 2, wherein the polyamide is a crosslinked aromatic polyamide having a structure represented by the following general formula (2), [Chem. 2] 90239912 53 provided that R1 and R2 each independently represent an alkyl group having 1 to 6 carbon atoms, a phenyl group, a benzyl group, COOR5, CONHR5, CON(R5)2, or OR5, and R5 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a benzyl group; R3 and R4 each independently represent hydrogen, 5 an alkyl group having 1 to 6 carbon atoms, a phenyl group, a benzyl group, COOR6, CONHR6, CON(R6)2, or OR6, and R6 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or a benzyl group; R7 is an aliphatic chain or an aliphatic ring comprising only a carbon atom and a hydrogen atom as a constituent element; and Ar8 is an aromatic ring having 6 to 14 carbon atoms 10 which may have a substituent.

Description

METHOD FOR SEPARATING AND RECOVERING COBALT SALT AND NICKEL SALT TECHNICAL FIELD [0001] The present invention relates to a method for separating and recovering a cobalt salt and a nickel salt from an aqueous solution containing cobalt and nickel, and particularly to a 10 method for efficiently separating and recovering a cobalt salt and a nickel salt using a nanofiltration membrane. BACKGROUND ART [0002] In recent years, with the economic development in the world, the demand for mineral resources has been greatly increased. However, of the mineral resources indispensable for a wide range of industries, including the semiconductor industry, some resources are economically unprofitable due to high mining and refining costs even if they have large reserves in the earth's crust, or some resources are localized in specific areas, and 20 mining thereof has been postponed until now. On the other hand, environmental problems are also getting a lot of attention, and construction of a recycling-oriented society is desired. In particular, in terms of reducing carbon dioxide emissions, the development of electric vehicles and motors and batteries used therein is accelerating. In particular, regarding batteries, a lithium ion battery is expected to be the main batteries of electric vehicles because 25 of energy density and lightness thereof. [0003] Cobalt is widely used in various industries as an alloy element of special steel or a magnetic material. For example, the special steel is used in the fields of aerospace, power generators, and special tools, taking advantage of excellent wear resistance and heat resistance 30 peculiar to cobalt. As the magnetic material, ferromagnetic alloy materials containing cobalt are used for small headphones, small motors, and the like. Cobalt is also used as a raw material for a positive electrode material in lithium ion batteries. In recent years, the demand for a cobalt-containing positive electrode material has been steadily increasing with Date Rei;:ue/Date Received 2022-11-28 2 the spread of the lithium ion battery for automobiles and power storage, as well as for mobile information processing terminals such as small personal computers and smartphones. [0004] Nickel is used as stainless steel by taking advantage of high gloss and corrosion 5 resistance. In recent years, similar to cobalt, the demand for nickel as a material for a lithium ion battery is increasing. [0005] Thus, as the demand for various rare metals increases, efforts to recover rare metals such as lithium, cobalt, and nickel from a lithium ion battery that has been used and a waste 10 material generated from a production process thereof have been promoted from the viewpoint ofrecycling valuable resources (Patent Literature 1 and non-Patent Literature 1). [0006] In addition, as a method for recovering nickel and cobalt from an aqueous solution, there is proposed a method for eluting and recovering high-concentration nickel and cobalt, in 15 which an aqueous solution containing nickel, cobalt, and other impurities is mixed with an ion exchange resin, nickel and cobalt are adsorbed on the ion exchange resin, and then sulfuric acid is brought into contact with the ion exchange resin obtained by solid-liquid separation (Patent Literature 2). 20 CITATION LIST PATENT LITERATURE [0007] Patent Literature 1: WO 2019/018333 Patent Literature 2: JP2019-l 73063A NON-PATENT LITERATURE [0008] Non-Patent Literature 1: Report of exploration project for promotion of mineral resource development in 201 7, research project of mineral resource industrial infrastructure 30 (basic survey on mineral resource securing strategy development), Mitsubishi Research Institute, Inc., Environment and Energy Business Headquarters, March 2018 SUMMARY OF INVENTION Date Rei;:ue/Date Received 2022-11-28 3 TECHNICAL PROBLEM [0009] The recovery of resources from waste lithium ion batteries is being put into practical use, centering on rare metals such as cobalt and nickel. Since a solvent extraction 5 method is the mainstream of the methods in the related art, the use of a large amount of an organic solvent has a large environmental impact, and stationary separation is necessary. Therefore, the scale of the entire facility is increased, which is disadvantageous in terms of cost. In addition, in the method for recovering nickel and cobalt from an aqueous solution 10 using an ion exchange resin, since the selective separability for nickel and cobalt is low and the obtained eluent contains both cobalt and nickel at high concentrations, it is necessary to perform a separation operation by solvent extraction in order to separate cobalt and nickel. [0010] An object of the present invention is to provide a method for recovering a cobalt 15 salt and a nickel salt with high efficiency by selectively separating cobalt and nickel from an aqueous solution containing cobalt and nickel by using a nanofiltration membrane without requiring a large amount of an organic