Gold Extraction from Cyanidation Tailing Using Microwave Chlorination Roasting Method

Abstract

At present, gold mines are increasingly scarce in the world. The yield of cyanidation tailing (CT) of refractory gold ores with a grade of 10 g/T is huge; however, the effective capitalization of the cyanidation tailing is a significant problem in the gold industry. In this work, a new treatment method, a microwave-roasting process developed. The effect of roasting temperature, calcium chloride concentration, holding time and mineral size on the recovery of Au researched under conventional and microwave conditions. It found that, under the same processing conditions, the Au recovery in the microwave field is much higher than that of conventional conditions. The preliminary reinforcing role of the microwave discussed in the recovery of gold. This might be because of the microwave absorption ability of CaCl2 is much better, heated quickly and the reactions intensified among CaCl2, O2, and H2O. As a result, the extraction of gold in CT drastically increased in the microwave field, and the microwave roasting technology shows the characteristics of environmental protection in terms of low energy consumption and high efficiency.