| The major impurities of the native cold and the crude gold produced as a byproduct of copper, lead, or bismuth smelting etc. are copper and silver. It is impossible to refine the native gold containing silver more than 8% by electrolytic refining or aqua regia treatment. In this study, in order to reduce the silver content in Au-Ag alloy by the pyrometallurgical technique, Cuprous Chloride Treatment was carried out, in which copper was substituted for silver in Au Ag alloy. The results obtained were as follows : 1. The silver in Au-Ag alloy was removed more than 90% by cuprous chloride treatment. 2. The substitution ratio for silver in Au-Ag alloy was enhanced by increasing the ratio of Cu₂Cl₂/Ag but unaffected by increasing the ratio of CaCl₂/Cu₂Cl₂. 3. Initially, the content of silver in Au-Ag alloy decreased rapidly as the temperature increased. However, the substitution ratio for silver decreased as the temperature increased after 25 minutes. |
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