Aqueous cobalt chloride solution refinement method

Patent metadata

Field	Value
Publication number	US-2018134577-A1
Application number	US-201615577521-A
Country	US
Kind code	A1
Filing date	May 20, 2016
Priority date	May 29, 2015
Publication date	May 17, 2018
Grant date	—

Abstract

The present invention provides an aqueous cobalt chloride solution refinement method, in which impurities can be efficiently removed from a cobalt salt solution.
Disclosed is a method for bringing metallic nickel into contact with an aqueous solution containing cobalt chloride to remove an impurity by a cementation reaction, in which the metallic nickel is washed with an acidic liquid having a pH of not more than 2.5 before the metallic nickel is brought into contact with the aqueous solution containing cobalt chloride. Since the metallic nickel is washed with the acidic liquid having a pH of not more than 2.5, a passive film on a surface of the metallic nickel is removed. The passive film is removed from the metallic nickel, and therefore, when the metallic nickel comes in contact with the aqueous solution containing cobalt chloride, an impurity more noble than the metallic nickel can be precipitated by the cementation reaction. In addition, since the metallic nickel is only washed with acid to be brought into contact with the aqueous solution containing cobalt chloride, the impurity can be easily removed from the aqueous solution containing cobalt chloride.

First claim

1 . An aqueous cobalt chloride solution refinement method for bringing metallic nickel into contact with an aqueous solution containing cobalt chloride to remove an impurity by a cementation reaction,
wherein the aqueous solution containing cobalt chloride has a pH of not less than 1.5 and not more than 2.5, and acidic liquid having a pH the metallic nickel is washed with an acidic liquid having a pH of not more than 2.5 before the metallic nickel is brought into contact with the aqueous solution containing cobalt chloride.

2 . The aqueous cobalt chloride solution refinement method according to claim 1 , wherein the aqueous solution containing cobalt chloride at room temperature is brought into contact with the metallic nickel.

3 . The aqueous cobalt chloride solution refinement method according to claim 1 , wherein the impurity is copper.

4 . The aqueous cobalt chloride solution refinement method according to claim 1 , wherein the aqueous solution containing cobalt chloride from which the impurity has been removed is used as a raw material of a positive electrode material containing in the composition of the positive electrode material nickel and cobalt in a nonaqueous electrolyte secondary battery.

5 . The aqueous cobalt chloride solution refinement method according to claim 4 , wherein
the aqueous solution containing cobalt chloride is a process liquid in a nickel smelting process, and the aqueous solution containing cobalt chloride from which the impurity has been removed is used in a liquid state as a raw material of the positive electrode material.

6 . The aqueous cobalt chloride solution refinement method according to claim 1 , wherein the aqueous solution containing cobalt chloride at a liquid temperature of 10 to 40° C. is brought into contact with the metallic nickel.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Ohara Hideki
• Asano Satoshi
• Tan Toshirou
• Takano Masatoshi

Classifications

• C01G51/08 Primary

  Halides; Oxyhalides · CPC title

• C01G51/085

  Chlorides; Oxychlorides · CPC title

• C22B23/06

  Refining · CPC title

• C22B23/0469 Primary

  by chemical substitution, e.g. by cementation · CPC title

• C22B3/46 Primary

  by substitution, e.g. by cementation · CPC title