Method For Manufacturing High Purity Tin, Electrowinning Apparatus For High Purity Tin And High Purity Tin

Abstract

Provided is a method for manufacturing high purity tin including: depositing electrodeposited tin on the surface of a cathode 11 by electrowinning in an electrolytic bath in which a diaphragm 14 is placed between an anode 12 and the cathode 11 , by using a raw material for tin as the anode 12 and a leachate obtained by electrolytically leaching the raw material for tin in a sulfuric acid solution as an electrolytic solution, the electrolytic solution containing a smoothing agent for improving a surface property of the electrodeposited tin; discharging the electrolytic solution from the electrolytic bath such that lead in the discharged electrolytic solution is removed; and putting the electrolytic solution from which lead is removed back into the electrolytic bath.

1 . A method for manufacturing high purity tin, the method comprising:
 depositing electrodeposited tin on the surface of a cathode by electrowinning in an electrolytic bath in which a diaphragm is placed between an anode and the cathode, by using a raw material for tin as the anode and a leachate obtained by electrolytically leaching the raw material for tin in a sulfuric acid solution as an electrolytic solution, wherein the electrolytic solution contains a smoothing agent for improving a surface property of the electrodeposited tin,   discharging the electrolytic solution from the electrolytic bath,   removing lead from the discharged electrolytic solution, and   putting the electrolytic solution from which lead is removed back into the electrolytic bath.   
     
     
         2 . The method for manufacturing high purity tin according to  claim 1 , which comprises:
 discharging the electrolytic solution in an anode side chamber in the electrolytic bath in which the anode is placed,   removing lead from the discharged electrolytic solution, and   putting the electrolytic solution from which lead is removed back into a cathode side chamber in the electrolytic bath in which the cathode is placed.   
     
     
         3 . The method for manufacturing high purity tin according to  claim 1 , wherein the smoothing agent comprises a nonionic surfactant which is a compound having an aryl group with one or more hydroxyl groups, the one or more hydroxyl groups being connected to the aryl group via methylene or a plurality of ethylene oxides. 
     
     
         4 . The method for manufacturing high purity tin according to  claim 1 , wherein the smoothing agent comprises a polyoxyethylene alkyl phenyl ether. 
     
     
         5 . The method for manufacturing high purity tin according to  claim 1 , which employs the raw material for tin with a purity of 4N (99.99%) or higher, the purity excluding the gas components of O, C, N and H. 
     
     
         6 . The method for manufacturing high purity tin according to  claim 1 , wherein the content of lead in the raw material for tin is 20 ppm or less. 
     
     
         7 . The method for manufacturing high purity tin according to  claim 1 , wherein an electrodeposited tin of high purity composed of a plate crystal is obtained. 
     
     
         8 . An electrowinning apparatus for high purity tin, the apparatus comprising:
 an anode made of a raw material for tin, a cathode which is opposite to the anode, and a diaphragm placed between the anode and the cathode;   an electrolytic bath for performing electrowinning by using an electrolytic solution which is a leachate obtained by electrolytically leaching the raw material for tin in a sulfuric acid solution to which a smoothing agent for improving a surface property of electrodeposited tin which is deposited on the cathode is added;   a tank for solution purification which discharges the electrolytic solution from the electrolytic bath and removes lead in the discharged electrolytic solution;   a filtration device which filtrates the electrolytic solution treated in the tank for solution purification; and   a liquid supply line which supplies the filtrated electrolytic solution to the electrolytic bath.   
     
     
         9 . The electrowinning apparatus for high purity tin according to  claim 8 , the apparatus comprises:
 discharging the electrolytic solution in an anode side chamber of the electrolytic bath in which the anode is placed,   removing lead from the discharged electrolytic solution, and   supplying the electrolytic solution from which lead is removed as an electrolytic solution in a cathode side chamber of the electrolytic bath in which the cathode is placed.   
     
     
         10 . High purity tin manufactured by the method for manufacturing high purity tin according to  claim 1 , wherein the content of lead is less than 0.1 ppm, the content of sulfur is 1.0 ppm or less, and the α ray count is 0.001 cph/cm 2  or less. 
     
     
         11 . High purity tin, wherein the content of lead is less than 0.05 ppm, the content of antimony is less than 0.5 ppm, the content of copper is less than 0.1 ppm, the content of sulfur is 0.5 ppm or less, and the α ray count is 0.001 cph/cm 2  or less.