浮选药剂对铅锌尾矿中重金属微生物溶出的影响

摘要

以青海某铅锌尾矿为研究对象,采用静态试验模拟研究了4种浮选药剂对尾矿在嗜酸氧化亚铁硫杆菌协同作用下重金属铅锌溶出的影响.结果发现,除丁胺黑药外,与未添加药剂相比,随溶出时间延长,其他3种黄药的存在均导致溶出体系的氧化还原电位升高而pH值降低,影响顺序均为异丁基黄药>乙基黄药≈戊基黄药>丁胺黑药.黄药体系Pb、Zn累积溶出量远大于黑药体系且Zn更易溶.50d时,Pb、Zn最大溶出浓度分别为77.60、167.00mg/L,其中异丁基黄药最有利于重金属铅锌的溶出.原电池效应、Cu2+对闪锌矿的活化以及浮选药剂的水解能力差异是导致不同浮选药剂对重金属溶出差异的主要原因.尾矿残渣 XRD 分析表明不同浮选药剂存在体系溶出过程中生成的新物质含量有所差异.%A static simulation test was carried out to study the effects of four kinds of flotation reagents on the release of lead and zinc withAcidthiobacillus ferrooxidans, taking a lead-zinc tailings as the research object in QingHai Province. The results showed that except butylamine aerofloat, redox potential rised and pH value dropped in the leaching systems with other three kinds of xanthate compared with the system added no reagents over time. And the influence order was isobutyl xanthate > ethyl xanthate ≈ amyl xanthate > butylamine aerofloat. The release amounts of Pb and Zn in the leaching systems with xanthate were much larger than that of aerofloat. Also Zn was more easy to dissolve. The largest concentration of Pb and Zn were 77.60, 167.00mg/L on 50th day, respectively. Isobutyl xanthate was best for heavy metal dissolution of Pb and Zn. Three reasons made the difference of dissolution of heavy metals in leaching systems with diverse flotation reagents. They were galvanic effect, the activation on sphalerite of Cu2+ and hydrolysis ability difference of flotation reagents. XRD analysis of tailings residue indicated that new materials were generated in the process of dissolution but the content was not same.