PYROMETALLURGICAL REDUCTION OF MILLER CHLORIDES WITH IRON

Mixtures of silver chloride and copper chloride are produced during go ld refining by the Miller process. A study has been made of the reduct ion with iron of a synthetic Miller chloride that contained 13.64 mass % silver and 2.42 mass% copper. The reactions were Fe + 2AgCl = 2Ag FeCl2 Fe + 2CuCl = 2Cu + FeCl2 The effects of smelting temperature and time and of additions of iron and borax were investigated. The result s were interpreted in terms of metal recovery and quality. Temperature did not have a significant effect on metal recovery above the melting -point of the metal product. Borax additions reduced vapour losses and improved metal recovery. With excess iron it was possible to achieve silver recoveries of about 100% and copper recoveries of about 70%. Th e metal product contained on average 76.1 mass% silver, 7.5 mass% copp er and 12.8 mass% iron.