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以青海某铅锌尾矿为研究对象进行酸预处理加速模拟静态淋溶实验,重点研究了氧化亚铁硫杆菌(At.f菌)接种量变化对尾矿中重金属Zn、As迁移释放的影响。结果表明,随时间延长,接种量变化均可导致淋溶体系pH值下降、电导率上升,氧化还原电位先上升后下降。At.f菌可明显促进Zn、As的释放,不同接种量对重金属的迁移释放作用不同;At.f菌存在下,Zn的释放能力大于As,Zn优先于As溶出,Zn、As浓度均表现为快速释放和缓慢释放并趋于平稳两个阶段,Evolich模型和Guass模型可分别描述Zn、As的释放过程。通过对细菌淋溶前后残渣SEM-EDS及XRD图谱分析发现,淋溶后尾矿颗粒结构疏松,表面腐蚀明显,生成了CaSO_4、钙磷石等不溶物,使Zn、As后期释放减慢。
Taking a lead - zinc mine tailing in Qinghai as an example, we accelerated the simulated leaching experiment by acid pretreatment. The effects of inoculum size of At.f bacteria on migration and release of heavy metals Zn and As in tailing were studied emphatically . The results showed that with the increase of time, the inoculation amount could cause the leaching system pH value to drop, the conductivity to rise and the redox potential to rise first then decrease. At.f bacteria can significantly promote the release of Zn, As, different inoculum effects on the migration and release of heavy metals; In the presence of At.f bacteria, Zn release capacity is greater than As, Zn preferential dissolution of As, Zn, As concentration showed For the rapid release and slow release and tends to be stable two stages, Evolich model and Guass model can be described separately Zn, As release process. The results of SEM-EDS and XRD showed that the tailings particles were leached loosely after leaching and the surface corrosion was obvious. CaSO_4, insoluble phosphate such as calcium phosphate were formed, and the release of Zn and As in the late stage was slowed down.