(1. 中南大学 化学化工学院，长沙 410083；
2. 长沙理工大学 化学与生物工程学院，长沙 410114；
3. 中南大学 有色金属资源化学教育部重点实验室，长沙 410083)
摘 要: 为探明黄铁矿在砷黄铁矿生物浸出过程中的作用与影响，选择纯黄铁矿和砷黄铁矿组成的矿浆浸出体系，考察黄铁矿和砷黄铁矿质量比以及黄铁矿粒度对体系中砷的浸出率以及砷的氧化状态的影响。结果表明：砷的浸出率随黄铁矿与砷黄铁矿质量比的增加而升高，随黄铁矿粒度的增加而减少。当黄铁矿的粒度小于74 μm、黄铁矿与砷黄铁矿质量比为10:2时，砷的最高浸出率为97.7%，比不添加黄铁矿时砷的浸出率提高了约43.18%。且黄铁矿可以加速As(Ⅲ)转化为As(Ⅴ)，降低矿浆对细菌的毒害，使生物浸出体系细菌密度提高、pH下降、氧化还原电位φh升高并与砷黄铁矿形成原电池效应，从而促进砷黄铁矿的浸出。
关键字: 黄铁矿；砷黄铁矿；氧化亚铁硫杆菌；生物浸出；原电池效应
（1. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. College of Chemistry and Biological Engineering, Changsha University of Science and Technology,
Changsha 410114, China;
3. Key Laboratory of Resources Chemical of Nonferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China）
Abstract:In order to clarify the function of pyrite in arsenopyrite bioleaching, pure pyrite and arsenopyrite were used to prepare a pulp system for studying the effect of the pyrite-to-arsenopyrite mass ratio and particles size of pyrite on the leaching rate and oxidation state of arsenic. The results show that the leaching rate of arsenic increases with increasing the mass fraction of pyrite and decreases with increasing the particle size of pyrite. When the mass ratio of pyrite to arsenopyrite is 10:2 and the particles size of pyrite is less than 74 μm, the highest leaching rate of arsenic is 97.7%, which is about 43.18 % higher than that of the arsenopyrite bioleaching without pyrite. The pyrite can accelerate the transform of As(Ⅲ) to As(Ⅴ), which reduces the toxicity of pulp and makes the bioleaching system have higher bacterial density, lower pH, higher oxidation-reduction potential, and generates galvanic effect with arsenopyrite. Therefore, the bioleaching efficiency of arsenopyrite can be promoted by adding pyrite.
Key words: pyrite; arsenopyrite; Acidithiobacillus ferrooxidans; bioleaching; galvanic effect
