In this study, the influence of pyrite on the leaching of arsenopyrite in sulfuric acid and iron-free 9K medium was investigated by leaching experiments and electrochemical analysis. During acid leaching, the addition of pyrite resulted in the further oxidation of arsenopyrite, for the reason that the galvanic interaction made the pH increase and redox potential decrease, and then the formation of arsenate precipitates with high crystallinity was depressed. While leaching in iron-free 9K medium, the buffer action keeping the pH stable promoted arsenopyrite dissolution as compared with acid leaching. And the addition of pyrite facilitated the arsenic extraction, but increasing the amount of pyrite added had no distinct impact on the further leaching of arsenopyrite. Electrochemical studies revealed that the presence of pyrite increased the conductivity of electrodes and electrolytes, verifying the catalytic effect of galvanic interaction on arsenopyrite leaching. Additionally, in the sulfuric acid electrolyte, the addition of pyrite also decreased the thickness of passivation layer on the arsenopyrite surface, confirming that the formation of ferric arsenate precipitates with high crystallinity was inhibited in the presence of pyrite. Therefore, the pyrite-promoted arsenopyrite oxidation in sulfuric acid was due to the galvanic effect and the control of pH and redox potential, whereas that in culture medium was only associated with the galvanic effect. Moreover, the electrochemical measurements also showed that the oxidation of elemental sulfur was the rate controlling step for arsenopyrite dissolution.

在这项研究中，通过浸出实验和电化学分析，研究了黄铁矿对砷黄铁矿在硫酸和无铁9K介质中浸出的影响。在酸浸过程中，黄铁矿的加入导致毒砂进一步氧化，其原因是电流相互作用使pH值升高，氧化还原电位降低，然后抑制了高结晶度砷酸盐沉淀的形成。在无铁9K培养基中浸出时，与酸浸相比，保持pH稳定的缓冲作用促进了毒砂的溶解。黄铁矿的添加促进了砷的萃取，但是增加黄铁矿的添加量对毒砂的进一步浸出没有明显的影响。电化学研究表明，黄铁矿的存在增加了电极和电解质的电导率，证实了电相互作用对毒砂黄铁矿浸出的催化作用。另外，在硫酸电解质中，黄铁矿的添加也使毒砂黄铁矿表面上的钝化层的厚度减小，证实在黄铁矿的存在下抑制了具有高结晶度的砷酸铁沉淀的形成。因此，硫酸中黄铁矿促进的毒砂氧化作用是由于电流作用以及对pH和氧化还原电位的控制，而在培养基中仅与电流作用有关。此外，电化学测量还表明，元素硫的氧化是毒砂溶解的速率控制步骤。