石英在微生物浸出黄铜矿体系中的溶出动力学  

Dissolution kinetics of quartz in bioleaching system of chalcopyrite

作　　者：林海[1] 周闪闪[1] 董颖博[1] 许晓芳[1] 

机构地区：[1]北京科技大学土木与环境工程学院,金属矿山高效开采与安全教育部重点实验室,北京100083

出　　处：《中南大学学报（自然科学版）》2015年第9期3167-3175,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51204011);中国博士后科学基金资助项目(2013T60063);北京市优秀博士学位论文指导教师科技项目(20121000803)~~

摘　　要：研究石英粒度、摇床转速及温度对石英在微生物浸出黄铜矿体系中溶出规律影响,并探讨溶出动力学。研究结果表明:石英在微生物-化学作用下Si溶出规律由于微生物及其代谢产物的影响与单独酸作用下溶出规律不相同。随着石英粒度减小、摇床转速对Acidthiobacillus ferrooxidans(At.f)菌生长适宜性和温度的增加,石英在微生物浸出黄铜矿体系中溶出Si的溶出率逐渐增大。当石英粒度r<43μm,摇床转速为160 r/min,温度为40℃,浸出48 d时,Si累计溶出率最高可达到2.37%。石英的溶解反应过程可用收缩核动力学模型1-(2/3)α-(1-α)2/3=k1t描述,该模型反映了控制整个溶出过程反应速率的决定步骤是内扩散速率,其表观活化能为78.51 k J/mol,由于浸矿细菌存在使其无法根据表观活化能判断控速步骤。铵黄铁矾等沉淀物覆盖在石英表面,增加了浸出液和溶出离子扩散阻力,验证了石英溶出过程受内扩散控制。The effects of the particle size, rotation speed, and temperature on quartz dissolution in the bioleaching system of chalcopyrite and the dissolution kinetics of quartz were researched. The results show that the dissolving rule of Si dissolved from quartz under the action of bacteria and metabolites is different from that under the action of acid solution. Smaller particles, more appropriate rotation speed for the growth adaptability of Acidthiobacillus ferrooxidans and higher temperature bring a higher leaching rate of Si in the bioleaching of chalcopyrite. Si leaching rate reaches the highest of 2.37% after leaching 48 d when the particle size of quartz, temperature, and rotation speed are smaller than 43 μm, 40 ℃, and 160 r/min, respectively. The dissolution of quartz fits the shrinking core model, 1-（2/3）α-（1-α）2/3=k1t, which shows that the decision step of controlling the overall reaction rate in the leaching process is internal diffusion. The apparent activation energy is 78.51 k J/mol. The precipitates of ammoniojarosite generate and cover the surface of quartz, which increases the diffusion resistance of the leaching solution and dissolved ions. These verify further that the dissolution of quartz is controlled by internal diffusion.

关 键 词：石英 微生物浸出 溶出动力学 收缩核模型 

分 类 号：TD925.5[矿业工程—选矿]