Solution for use in extraction of cobalt, cobalt solution, and method for collecting cobalt

Abstract

The purpose of the present invention is to provide a solution for use in the extraction of cobalt, whereby it becomes possible to extract cobalt at lower cost and more safely compared with a case in which a conventional one is used. The solution for use in the extraction of cobalt according to the present invention comprises: an ionic liquid containing a quaternary ammonium group; and an organic solvent which exists in such a state that the organic solvent is mixed with the ionic liquid and which has a kauri-butanol value of 60 or more.

1 . A solution for use in extraction of cobalt, comprising:
 an ionic liquid containing a quaternary ammonium group; and   an organic solvent that is present in a state of being mingled with the ionic liquid and has a kauri-butanol value of 60 or more.   
     
     
         2 . A solution for use in extraction of cobalt according to  claim 1 , wherein the solution comprises the organic solvent at a volume ratio of 2% or more and 50% or less. 
     
     
         3 . A solution for use in extraction of cobalt according to  claim 1 , wherein the solution comprises the organic solvent at a volume ratio of 5% or more and 15% or less. 
     
     
         4 . A solution for use in extraction of cobalt according to  claim 1 , wherein the organic solvent comprises an alkylbenzene derivative or toluene. 
     
     
         5 . A solution for use in extraction of cobalt according to  claim 1 , wherein the ionic liquid comprises tri-octyl-methyl-ammonium-chloride (TOMAC) or di-octadecyl-di-methyl-ammonium-chloride. 
     
     
         6 . A solution for use in extraction of cobalt according to  claim 1 , wherein the solution has a viscosity of 0.02 Pa·s or more and 0.5 Pa·s or less. 
     
     
         7 . A solution for use in extraction of cobalt according to  claim 1 , wherein the solution has a solubility in water of 0.01% or less. 
     
     
         8 . A cobalt solution, comprising:
 the solution for use in extraction of cobalt of  claim 1 ; and   an aqueous solution of cobalt and an acid containing chlorine, the aqueous solution being dissolved in the solution for use in extraction of cobalt,   wherein cobalt is dissolved in the solution for use in extraction of cobalt.   
     
     
         9 . A method of collecting cobalt, comprising dissolving an aqueous solution of cobalt and an acid containing chlorine in a solution for use in extraction of cobalt, the solution including an ionic liquid containing a quaternary ammonium group, and an organic solvent that is present in a state of being mingled with the ionic liquid and has a kauri-butanol value of 60 or more, to dissolve cobalt in the solution for use in extraction of cobalt to separate and collect cobalt. 
     
     
         10 . A method of collecting cobalt according to  claim 9 , wherein the method comprises:
 (a) dissolving a compound containing cobalt in an acid to prepare an acidic aqueous solution;   (b) dissolving the acid in the solution for use in extraction of cobalt to extract cobalt into the solution for use in extraction of cobalt; and   (c) bringing the solution for use in extraction of cobalt into contact with water to perform back extraction of cobalt into the water, followed by collection thereof.   
     
     
         11 . A method of collecting cobalt according to  claim 9 , wherein the solution for use in extraction of cobalt contains the organic solvent at a volume ratio of 2% or more and 50% or less. 
     
     
         12 . A method of collecting cobalt according to  claim 9 , wherein the solution for use in extraction of cobalt contains the organic solvent at a volume ratio of 5% or more and 15% or less. 
     
     
         13 . A method of collecting cobalt according to  claim 9 , wherein the organic solvent comprises an alkylbenzene derivative or toluene. 
     
     
         14 . A method of collecting cobalt according to any  claim 9 , wherein the ionic liquid comprises tri-octyl-methyl-ammonium-chloride (TOMAC) or di-octadecyl-di-methyl-ammonium-chloride. 
     
     
         15 . A method of collecting cobalt according to  claim 10 , wherein:
 the compound contains nickel; and   the (b) comprises dissolving the acidic aqueous solution in the solution for use in extraction of cobalt to extract cobalt into the solution for use in extraction of cobalt, and to collect nickel remaining in the acidic aqueous solution.   
     
     
         16 . A method of collecting cobalt according to  claim 10 , wherein:
 the compound contains at least one of manganese and copper; and   the method further comprises (d) bringing the acidic aqueous solution into contact with a chelate resin to separate at least one of manganese and copper from the acidic aqueous solution.   
     
     
         17 . A method of collecting cobalt according to  claim 10 , wherein:
 the compound contains iron; and   the method further comprises (e) removing iron from the acidic aqueous solution.   
     
     
         18 . A method of collecting cobalt according to  claim 17 , wherein the (e) comprises:
 adding hydrogen peroxide to the acidic aqueous solution to oxidize iron;   adjusting a pH of the acidic aqueous solution to 1 or more and 6 or less to precipitate iron; and   removing the precipitated iron by filtration.   
     
     
         19 . A method of collecting cobalt according to  claim 10 , wherein the (a) comprises adding a chloride to the acidic aqueous solution. 
     
     
         20 . A method of collecting cobalt according to  claim 10 , wherein the compound contains a residue after collection of tungsten from a cemented carbide scrap containing tungsten and cobalt.