采用酸浸法提取硫铁矿尾矿中有价元素铜。研究了硫酸质量分数、浸出时间、矿石粒度、矿石投加量、浸出温度和转速对铜浸出的影响。在单因素实验的基础上，采用正交实验法对浸出工艺条件进行优化。采用扫描电镜(SEM)和能谱仪(EDS)对酸浸前后尾矿表面的微观形貌进行了分析，初步探讨了酸浸反应后期抑制Cu浸出的影响机制。结果表明，酸浸铜的最佳工艺条件为：硫酸质量分数30%、浸出时间6 h、矿石粒度150 ?m、矿石用量5 g、浸出温度108℃、转速440 r/min，在此条件下，铜的浸出率为50.68%。扫描电镜和能谱分析表明，浸出残渣表面被微米级的二氧化硅颗粒紧密包裹，钝化了后期的浸出反应。

In order to reutilize these industrial wastes of pyrite tailings, the effects of the six single factors of sulfuric acid concentration, leaching time, ore particle size, ore dosage, leaching temperature and agitation speed on leaching copper in the pyrite tailings and the subsequent L18(37) orthogonal optimization experiments had comprehensively been investigated. Furthermore, the mechanism inhibiting further acid leaching reaction had been revealed by the scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The research result showed that the optimal condition of leaching copper was sulfuric acid mass fraction of 30%, leaching time of 6 h, ore particle size of 150 ?m, ore dosage of 5 g, leaching temperature of 108℃, and agitation speed of 440 r/min. Under the condition, the Cu leaching rate can reach 50.68%. The priority of influencing factors of sulfuric acid mass fraction>leaching temperature>ore dosage>leaching time>ore particle size>agitation speed was obtained via the range analysis of the orthogonal test, and moreover the six factors were extremely significant via the variance test. Finally, the SEM and EDS had revealed that the surfaces of the leached residues had tightly been encapsulated by micron-sized particulate SiO2, so that it passivated the further leaching reaction progress and limited the constant increase of the leaching rate at the late stage of acid leaching. Therefore, it was very necessary to loosen the SiO2 coating layer and release its passivation at the later stage of leaching reaction for the sake of further improving the leaching copper in the silicon-rich pyrite tailings.