Sulphidic refractory gold ore pre-treatment by selective and bulk flotation methods

Abstract

In sulphidic refractory gold ores, fine gold particles may be highly disseminated and locked up in sulphide minerals such as pyrite and arsenopyrite. Hence, pre-treating processes are necessary to extract gold for further processing methods like cyanidation. In this paper, the selective and bulk flotation methods are considered as primary sulphidic refractory gold ore pre-treating options. The results show that it is impractical to remove arsenic (As) and antimony (Sb) from downstream processes by using selective flotation. It was observed that 22% of total Sb and 31.1% of As remained in the final tailings. In this case, 24% of gold was recovered in the initial stage of flotation. On the contrary, in the bulk method of flotation, which was aimed at maximizing the gold (Au) recovery, the maximum Au recovery of 90.6% obtained after 60min of flotation at the grind size with d80 of 146μm. The bulk flotation method as a pre-treating method resulted in the concentrate with less toxic chemical elements such as As and Sb.