Gold Solubility in Smelting Slags for the Recycling of Industrial and Mining Wastes

Abstract

Gold is one of the most valuable and precious metals. But, the extraction efficiency of gold from natural resources is very low and labor-intensive due to very low concentration of gold, i.e., 1–5 ppm, which means that gold extraction processes produce extensive amounts of tailings. The gold content in printed circuit board (PCB) of waste mobile phone is about 100–400 ppm, which is enormously greater than that found in natural ores. Consequently, a requirement for recycling waste PCB and gold mine tailings becomes increasing for maintaining sustainable society. Because the pyrometallurgical processes are issued due to economic reasons, it is needed to understand the thermodynamic behavior of gold in smelting slags under oxidizing and reducing atmosphere at high temperatures. Therefore, in this study, the effect of slag chemistry, oxygen potential and temperature on gold solubility in smelting slags are discussed.