Comprehensive recovery technology for Te, Au, and Ag from a telluride-type refractory gold mine

Abstract

While extracting gold and silver from telluride-type gold deposits, it is beneficial to develop a comprehensive recovery technology for tellurium. In this paper, we report process mineralogy based on the backward processing technology and the low comprehensive utilization rate of typical telluride-type gold deposits in Xiaoqinling, China. The findings show that tellurium, gold, and silver are the most valuable elements in the ore fissures and gangue minerals and are encapsulated in metallic sulfur ore in the form of altaite, hessite, calaverite, antamokite and natural gold. The flotation method was innovatively applied in this study to comprehensively recover Te, Au and Ag. The results show that when the ore particle size was –0.074 mm (70%), the flotation pulp density was 33%, the pulp pH was 8, and the combined collector (isoamyl xanthate + ethyl thio- carbamate (1:1)) was 120 g/t, in the process involving one rough flotation step, two cleaning flotations and two scavenging flotations as well as a continuous 8 d industrial test, the recovery degree was stable and the average grades of Te, Au, and Ag were 241.61, 90.30, and 92.74 g/t with 95.42%, 97.28%, and 94.65% recovery rates, respectively; thus, excellent recovery degrees were obtained. Compared with the original flotation process, the recovery rates of Te, Au, and Ag were increased by 19.91%, 6.93%, and 5.67%, which boosted the effective enrichment of all valuable elements in the telluride-type gold mine and achieved technological progress.