Increased the leaching rate of realgar by adding Ag+

摘要

As an important mineral in gold ores bearing arsenic, realgar is able to inhibit gold dissolution through consuming cyanide and oxygen and/or forming passivation film on the gold surface,during conventional cyanidation. The decomposition of this mineral in natural and industrial conditions can cause arsenic dissolution, resulting in environmental pollution. So the study on the mechanism of the realgar decomposition is necessary not only for optimizing industrial processes but also for clearing up the environmental problem. The previous studies showed that the leaching efficiency of realgar is very low. In this work, the catalytic effect of Ag+ions on the dissolution of realgar was studied. It is shown that the efficiency of chemical leaching and bioleaching of realgar in no presence of Ag+ions are very low while the activity of At.f and S.s was pretty high. By addition of Ag+ions in the same leaching systems, the leaching rate is enhanced greatly. Based on consideration of influences of concentrations of Fe3+and temperature, a catalytic mechanism of Ag+ions was inferrered.