Aqueous cobalt chloride solution purification method

Patent metadata

Field	Value
Publication number	US-2018148344-A1
Application number	US-201615577507-A
Country	US
Kind code	A1
Filing date	May 20, 2016
Priority date	May 29, 2015
Publication date	May 31, 2018
Grant date	—

Abstract

The present invention provides an aqueous cobalt chloride solution purification method, in which impurities can be efficiently removed from a cobalt salt solution.
Provided is a method for bringing metallic nickel into contact with an aqueous solution containing cobalt chloride to remove an impurity by a substitution reaction, in which the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5. Since the pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5, a passive film on a surface of the metallic nickel can be effectively removed. When the passive film is removed, the metallic nickel comes in contact with the aqueous solution containing cobalt chloride, so that an impurity more noble than the metallic nickel can be precipitated by the substitution reaction. In addition, since the metallic nickel is only 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 purification method for bringing metallic nickel into contact with an aqueous solution containing cobalt chloride to remove an impurity by a substitution reaction,
wherein a pH of the aqueous solution containing cobalt chloride is adjusted to not less than 1.5 and not more than 2.5.

2 . The aqueous cobalt chloride solution purification method according to claim 1 , wherein a temperature of the aqueous solution containing cobalt chloride is maintained at higher than 50° C. and not higher than 80° C.

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

4 . The aqueous cobalt chloride solution purification 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 purification 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 purification method according to claim 2 , wherein a temperature of the aqueous solution containing cobalt chloride is maintained at not lower than 60° C. and not higher than 80° C.

Assignees

• Sumitomo Metal Mining Co

Inventors

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

Classifications

• C22B3/46 Primary

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

• C22B23/0469

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

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• C01G51/085 Primary

  Chlorides; Oxychlorides · CPC title

• H01M2004/028

  Positive electrodes · CPC title