(1. 中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 在pH為1.5、溫度為65 ℃、廢渣濃度為5%的優(yōu)化浸出條件下，通過搖瓶實(shí)驗(yàn)，結(jié)合掃描電子顯微鏡、X射線衍射儀和BCR法三步連續(xù)提取，研究生物浸提Pb/Zn冶煉廢渣后余渣中重金屬元素的潛在毒性。結(jié)果表明：生物浸出3d后，廢渣中As、Cd、Cu和Zn含量分別由原渣中的5 055、20.7、10 718和29 681 g/t降至1 107、2.5、410和4 821 g/t；而Pb主要以硫酸鉛及黃鉀鐵釩類物質(zhì)等形式沉積在浸出渣中。余渣中As、Cd、Cu、Pb和Zn等重金屬主要以殘留態(tài)存在，其環(huán)境活性和潛在危害遠(yuǎn)低于中國有色金屬工業(yè)固體廢物污染控制標(biāo)準(zhǔn)(GB5085—85)的規(guī)定，生物浸出能有效實(shí)現(xiàn)Pb/Zn冶煉廢渣的無害化機(jī)理。
關(guān)鍵字: Pb/Zn冶煉廢渣；生物浸出；浸出毒性；無害化機(jī)理
（1. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China;
2. School of Resources Processing and Bio-engineering, Central South University, Changsha 410083, China）
Abstract:Shaking flask experiments were used to study the bioleaching of heavy metals from Pb/Zn smelting slag under the optimized conditions, which are determined to be pH1.5, 65 ℃ and pulp density of 5%. The residues from the bioleaching were analyzed by scanning electron microscopy, XRD and three-stage BCR sequential extraction procedure. The results show that the heavy metal contents (As, Cd, Cu and Zn) are sharply decreased after 3-day leaching, from 5 055, 20.7, 10 718 and 29 681 g/t to 1 107, 2.5, 410 and 4 821 g/t, respectively. However, the lead mainly deposits in the residues as lead sulfate and jarosite-type compounds. As, Cd, Cu, Pb and Zn in the residues mainly exist in residual form. The environmental availability and potential risk of heavy metals are significantly less than those commended by the Standard for Solid Wastes From Nonferrous Metal Industry of China (GB5085—85), proving that bioleaching can effectively reduce the potential toxicity of Pb/Zn smelting slags.
Key words: Pb/Zn smelting slag; bioleaching; leaching toxicity; innocuous treatment
