THE REDUCTION OF MILLER CHLORIDES WITH SODIUM-CARBONATE AND CARBON

In the refining of molten gold with chlorine, a copper chloride-silver chloride mixture is produced which is known as miller chloride. In th is work the reduction of the chloride mixture with sodium carbonate an d charcoal was studied at temperatures above 1100 degrees C according to the following reactions: 2AgCl+Na2CO3=2Ag+2NaCl+CO2+1/2O(2) 2CuCl+N a2CO3+C=2Cu+2NaCl+CO2+CO. The effects of sodium carbonate additions, c harcoal additions, and temperature on the recovery of silver and coppe r was studied. In order to ensure the maximum recovery of silver and c opper, the sodium carbonate addition should be about 10% in excess of the stoichiometric and the charcoal addition should be about 100% in e xcess of the stoichiometric. Some separation of the silver from the co pper could be achieved by controlling the sodium carbonate addition.