Mineralogical Characteristics and Refractory Properties of Arsenic-bearing Gold Concentrate

Abstract

Abstract The arsenic-bearing gold ore in Anhui, China is an extremely refractory gold ore, and the cyanide leaching rate of gold concentrate is only 30%. The mineralogical factors of the low leaching rate were discussed by process mineralogical analysis. The results demonstrate that the gold concentrate contains 20.30 g/t gold, 3.39% arsenic, 29.80% sulfur, and 4.10% iron. Gold exists in the occurrence states of metallic mineral-wrapped gold, gangue mineral-wrapped gold, and fissure gold, which account for 64.90%, 8.31%, and 26.79% respectively. Pyrite, arsenopyrite, realgar, sphalerite, and pyrrhotite are the main metallic minerals in the gold concentrate. Among them, pyrite accounts for 51.20%, and arsenopyrite accounts for 24.30%. Gangue minerals include feldspar, sericite, quartz, calcite, and chlorite. Among them, feldspar, sericite, and quartz account for 30.30%, 22.70%, and 22.10% respectively. In addition, the grain size distribution and distribution characteristics of various minerals are obtained, and the texture and structure of the gold ore are analyzed. Pyrite and arsenic phase are the main factors causing the low gold leaching rate. The presence of carbonate minerals and clay minerals also has an effect on the rate of gold leaching. The oxidation pretreatment can increase the gold leaching rate to about 94%. The findings provide a theoretical foundation for the selection of manufacturing techniques in businesses and play an important guiding role in the development of similar ores.