Pressure Oxidation-Chloride Leaching of High-Sulfur and High-Arsenic Refractory Gold Concentrate
摘要
In this paper, the effect of factors and mineralogical changes in the pressure oxidation pretreatment of high-sulfur and high-arsenic refractory gold concentrates were considered. The effect of pretreatment conditions and optimum conditions on gold leaching was considered by pressure oxidating the gold concentrate and chloride leaching the residue under various conditions and the changes in the physicochemical properties of the mineral during the pretreatment were confirmed from the results of XRD and SEM analysis. The results showed that the desulfurization rate was 93.85%, gold chloride leaching rate was 94.54% under following conditions; reaction temperature 180°C, concentrate size 0.061–0.075 mm, oxygen partial pressure 0.8 MPa, initial sulfuric acid concentration 60 g/L, liquid–solid ratio 4 : 1, stirring rate 600 rpm and reaction time 120 min. In addition, the XRD and SEM analysis results of the gold concentrate and the pressure oxide residue showed that the surface of the pressure oxide residue was a fine porous structure and the dense and durable structure of the sulfide ore was mainly destroyed. The process produces no toxic SO2 or arsenic containing gases, offering an environmentally friendly and technically feasible approach for industrial treatment of refractory gold concentrates.