Recovery method of tin and nickel from scraps of steel ball for barrel plating

Abstract

The present invention relates to a method of recovering tin and nickel compounds with high purity at a high yield from scrap steel balls for barrel plating through simple processes without using an excess amount of a solvent, the method using an eco-friendly dry pretreatment and subsequent processes including hydrogen reduction and electrolytic refining under certain conditions.

What is claimed is: 
     
         1 . A method of recovering tin and nickel compounds, which comprises the steps of: subjecting scrap steel balls for barrel plating to a heat treatment at a temperature of 300° C. to 700° C.; grinding and sorting the heat-treated scrap; adding tin and nickel compounds being separated from the grinding and sorting step to an acidic solution; filtering the acidic solution having the tin and nickel compounds added thereto; subjecting residues of the filtering step to a hydrogen reduction treatment at a temperature of 600° C. to 1000° C. to recover tin; and subjecting the recovered tin to electrolytic refining. 
     
     
         2 . The method of recovering tin and nickel compounds in accordance with  claim 1 , wherein the scrap steel balls for barrel plating comprise 10 to 98 wt % of an iron component, 1 to 80 wt % of a tin compound, and 1 to 80 wt % of a nickel compound. 
     
     
         3 . The method of recovering tin and nickel compounds in accordance with  claim 1 , wherein the scrap steel balls for barrel plating have a spherical or circular shape having a longest diameter of 0.1 to 5 mm. 
     
     
         4 . The method of recovering tin and nickel compounds in accordance with  claim 1 , wherein the scrap steel balls for barrel plating are obtained from a barrel plating process for an electronic part. 
     
     
         5 . The method of recovering tin and nickel compounds in accordance with  claim 1 , wherein grinding the heat-treated scrap steel balls for barrel plating is carried out by using a ball mill or a vibration mill. 
     
     
         6 . The method of recovering tin and nickel compounds in accordance with  claim 1 , wherein the acidic solution with the tin and the nickel compounds as separated in the grinding and sorting step added thereto has a concentration of 0.1 to 10 M. 
     
     
         7 . The method of recovering tin and nickel compounds in accordance with  claim 1 , wherein the acidic solution comprises nitric acid, or a mixture of nitric acid and hydrochloric acid. 
     
     
         8 . The method of recovering tin and nickel compounds in accordance with  claim 1 , further comprising a step of controlling pH of the filtrate of the acidic solution having the tin and nickel compounds added thereto to between 2 and 5 to eliminate the iron component. 
     
     
         9 . The method of recovering tin and nickel compounds in accordance with  claim 8 , further comprising a step of evaporating and concentrating the filtrate obtained after the iron component is eliminated to recover the nickel compound. 
     
     
         10 . The method of recovering tin and nickel compounds in accordance with  claim 1 , wherein the electrolytic refining is carried out at a temperature of 10° C. to 60° C. with a current density of 0.04 A/dm 2  to 4.0 A/dm 2  and a distance between electrodes of from 1 mm to 500 mm.