METHOD FOR TREATING SULFIDE

Abstract

Provided is a method for treating a sulfide, the method being suitable for obtaining nickel and/or cobalt from a sulfide containing copper and nickel and/or cobalt. The method relates to a method for treating a sulfide containing copper and nickel and/or cobalt, the method including pulverizing the sulfide by subjecting the sulfide to a pulverizing treatment so as to obtain a pulverized sulfide having a particle size of 800 μm or less; and leaching the pulverized sulfide by subjecting the pulverized sulfide to a leaching treatment with an acid under a condition in which a sulfurizing agent is present to obtain a leachate. For example, the sulfide to be treated is generated by reducing, heating, and melting a waste lithium-ion battery to obtain a molten body and adding a sulfurizing agent to the molten body to sulfurize the molten body.

Claims

1. A method for treating a sulfide comprising copper and nickel and/or cobalt, the method comprising: pulverizing the sulfide by subjecting the sulfide to a pulverizing treatment to obtain a pulverized sulfide having a particle size of 800 μm or less; and leaching the pulverized sulfide by subjecting the pulverized sulfide to a leaching treatment with an acid under a condition in which a sulfurizing agent is present, to obtain a leachate.

2. The method for treating a sulfide according to claim 1, wherein, in the leaching step, a leaching treatment is performed with at least one or more types selected from sulfuric acid, hydrochloric acid, and nitric acid to obtain a leachate.

3. The method for treating a sulfide according to claim 1, further comprising reducing the leachate by using a metal that has a lower standard reduction potential than copper.

4. The method for treating a sulfide according to claim 3, further comprising oxidizing and neutralizing a solution obtained in the reduction step by adding an oxidant and a neutralizing agent to the solution obtained in the reduction step, to obtain a solution containing nickel and/or cobalt.

5. The method for treating a sulfide according to claim 4, wherein the oxidant is one or more types selected from hydrogen peroxide and hypochlorous acid.

6. The method for treating a sulfide according to claim 4, wherein the neutralizing agent is one or more types selected from sodium hydroxide and potassium hydroxide.

7. The method for treating a sulfide according to claim 1, wherein the sulfide is generated by adding a sulfurizing agent to a molten body obtained by reducing, heating, and melting a waste lithium-ion battery.

8. A method for recovering a valuable metal from a waste lithium-ion battery, the method comprising obtaining a leachate by leaching a sulfide comprising copper and nickel and/or cobalt with an acid, the sulfide being generated by sulfurizing a molten body obtained by reducing, heating, and melting the waste lithium-ion battery, wherein the sulfide is subjected to a pulverizing treatment so as to have a particle size of 800 μm or less and the pulverized sulfide is subjected to a leaching treatment with an acid under a condition in which a sulfurizing agent is present.

9. A method for recovering a valuable metal from a waste lithium-ion battery, the method comprising a pyrometallurgical treatment, in which the waste lithium-ion battery is reduced, heated, and melted to obtain a molten body, and sulfurizing the molten body to obtain a sulfide containing copper and nickel and/or cobalt, and a hydrometallurgical treatment, in which the sulfide is leached with an acid, wherein, in the hydrometallurgical treatment, the sulfide is pulverized so as to have a particle size of 800 μm or less, and the pulverized sulfide is subjected to a leaching treatment with an acid under a condition in which a sulfurizing agent is present.

10. The method for treating a sulfide according to claim 2, further comprising reducing the leachate by using a metal that has a lower standard reduction potential than copper.

11. The method for treating a sulfide according to claim 5, wherein the neutralizing agent is one or more types selected from sodium hydroxide and potassium hydroxide.

12. The method for treating a sulfide according to claim 2, wherein the sulfide is generated by adding a sulfurizing agent to a molten body obtained by reducing, heating, and melting a waste lithium-ion battery.

13. The method for treating a sulfide according to claim 3, wherein the sulfide is generated by adding a sulfurizing agent to a molten body obtained by reducing, heating, and melting a waste lithium-ion battery.

14. The method for treating a sulfide according to claim 4, wherein the sulfide is generated by adding a sulfurizing agent to a molten body obtained by reducing, heating, and melting a waste lithium-ion battery.

15. The method for treating a sulfide according to claim 5, wherein the sulfide is generated by adding a sulfurizing agent to a molten body obtained by reducing, heating, and melting a waste lithium-ion battery.

16. The method for treating a sulfide according to claim 6, wherein the sulfide is generated by adding a sulfurizing agent to a molten body obtained by reducing, heating, and melting a waste lithium-ion battery.

Description

EXAMPLES

[0077] Hereinafter, examples of the present invention will be described more specifically, but the present invention is not limited to the following examples in any way.

Example 1

[0078] A waste lithium-ion battery (waste LIB) was heated, melted, and reduced to obtain a molten body, and a sulfurizing agent was added to the resulting molten body to obtain a sulfide containing copper, nickel, and cobalt. Using this sulfide as a treatment target, the sulfide was subjected to a treatment for separating nickel and cobalt from copper which are contained in the sulfide.

(Pulverizing Step)

[0079] Firstly, the sulfide containing copper, nickel, and cobalt was pulverized by a jaw crusher and a vibration mill to obtain a pulverized sulfide having a particle size of 800 μm or less. Incidentally, the particle size of the pulverized sulfide is an average particle size measured based on a laser diffraction scattering method, using a particle size analyzer (SALD-7000 manufactured by Shimadzu Corporation). In addition, Table 1 below shows the results of metal grade obtained by analyzing the obtained pulverized sulfide using an ICP analyzer.

TABLE-US-00001 TABLE 1 Ni Co Cu Fe P S Metal 8 8 65 1.5 0.5 17 grade (%)

(Leaching Step)

[0080] Next, sulfuric acid in a sufficient amount to leach nickel and the pulverized sulfide was prepared. Then, a sulfurizing agent (sulfur) in an amount of 1 equivalent with respect to an amount of copper contained in the pulverized sulfide was added, and the pulverized sulfide was subjected to a leaching treatment with an acid by setting a slurry concentration to 100 g/L under a condition in which a sulfurizing agent was present. This leachate was analyzed by the ICP analyzer. Analytical values (g/L) of each elemental component are shown in Table 2.

(Reduction Step)

[0081] At the end of leaching, solid-liquid separation was performed, and a reduction treatment was performed on the obtained leachate using a reducing agent (nickel sulfide), and filtration was performed to separate solid and liquid to obtain a filtrate (reduced solution). The reduced solution was analyzed by the ICP analyzer. Analyses values (g/L) of each element component are shown in Table 2.

(Oxidation and Neutralization Step)

[0082] Next, the oxidation and neutralization treatment was performed by adding a hydrogen peroxide solution (oxidant) with a concentration of 30% to the reduced solution obtained, and after the addition of hydrogen peroxide (oxidant), adding an aqueous solution of sodium hydroxide (neutralizing agent), to adjust the oxidation-reduction potential (ORP) to 400 mV or more as determined using a silver/silver chloride electrode as a reference electrode and pH value to 4 or more. After the reaction, the reaction mixture was filtrated to separate solid and liquid to obtain a filtrate (neutralized solution). This filtrate (neutralized solution) was analyzed by the ICP analyzer. Analyses values (g/L) of each element component are shown in Table 2.

TABLE-US-00002 TABLE 2 (g/L) Ni Co Cu Fe P Leachate 6 6 3 1.5 0.5 Reduced 6 6 0.001 1.5 0.5 solution Neutralized 6 6 0.001 0.001 0.001 solution

[0083] As can be seen from Table 2, the concentration of Cu in the leachate was 3 g/L, which was sufficiently low. From this, it can be seen that nickel and cobalt can be efficiently and selectively separated from copper by subjecting a pulverized sulfide which contains nickel and cobalt and copper and which has a predetermined particle size to a leaching treatment with an acid under a condition in which a sulfurizing agent is present.