Bio-oxidation of a high-sulfur and high-arsenic refractory gold concentrate using a two-stage process. (May 2018)

• Record Type: Journal Article
• Authors: Wang, Guohua; Xie, Shuibo; Liu, Xinxing; Wu, Yonghong; Liu, Yingjiu; Zeng, Taotao
• Is Part Of: Minerals engineering. Volume 120(2018)
• Page Start: 94
• Page End: 101
• Publication Date: 2018-05
• Subjects: Bio-oxidation -- Two-stage process -- Arsenopyrite -- Gold concentrate; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2018.02.013
• Languages: English
• ISSNs: 0892-6875

Abstract

Graphical abstract: Highlights: Effect of two-step process on the oxidation efficiency of arsenopyrite was studied. Elemental sulfur was generated and hindered oxidation in the chemical stage. Elemental sulfur did not influence the biological oxidation. Partly disrupted surface and shrunken particle size improved the oxidation level. Abstract: To improve the oxidation rate of high-sulfur and high-arsenic refractory gold concentrate (HGC), a two-stage chemical-biological oxidation approach, which contained a high-temperature chemical oxidation stage (ferric-leaching stage) and a subsequent biological oxidation stage with mesophiles, was used in this experiment. The surface analysis of pure arsenopyrite using scanning electron microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) indicated that the surface lattice structure was partly disrupted after chemical oxidation; as a result, the subsequent biological oxidation rate during the second stage improved significantly. The extraction levels of Fe, As and S were 49.8%, 50.4% and 51.0%, respectively, in the normal biological oxidation system, while the values increased to 63.3%, 64.2% and 63.3%, respectively, following the two-stage process. Accordingly, the recovery rate of gold increased by 16.8% using the two-stage process compared to that of the one-stage biological oxidation approach.