不同pH条件下生石灰对电解锰渣中重金属释放的影响

Effect of Quicklime on Release of Heavy Metals from Electrolytic Manganese Residue in Different pH

摘要: 电解锰渣是电解锰生产过程中产生的一种工业固体废弃物，含有大量的重金属，存在严重的环境污染风险。本研究通过室内模拟方法探讨了不同pH (4、5、6、纯净水以及8)条件下生石灰添加量(1%、2%、3%、4%和5%)对电解锰渣中Mn、Cd、Cu、Zn、Pb和Tl等重金属释放行为的影响。结果表明，浸出液pH随浸提液pH的升高而升高，浸出液Eh随着生石灰添加比例的升高而降低，同时，生石灰添加比例的提高能显著抑制重金属的浸出，浸提液pH 4时，生石灰添加量从1%增至5%时，浸出液Mn浓度由126.65 mg/L降至4.44 mg/L，降幅达96.5%，而pH升至8时，5%添加组Mn浓度降低，同时，生石灰添加比例对Cu、Zn、Pb和Tl同样具有显著影响，pH 4浸提条件下，与1%添加组相比，5%添加组中Cu、Pb和Tl的下降幅度分别达到36.16%、86.09%、65.90%和47.84%，表明不同重金属对pH敏感度及其沉淀物稳定性存在显著差异。

Abstract: Electrolytic manganese residue is a kind of industrial solid waste produced in the process of electrolytic manganese production, which contains a lot of heavy metals and has serious environmental pollution risk. In this study, the effects of the amount of quick lime (1%, 2%, 3%, 4% and 5%) on the release behavior of heavy metals such as Mn, Cd, Cu, Zn, Pb and Tl in electrolytic manganese slag at different pH values (4, 5, 6, pure water and 8) were investigated by indoor simulation. The results showed that the pH of the leaching solution increased with the increase of the pH of the leaching solution, and the Eh of the leaching solution decreased with the increase of the proportion of quicklime added. Meanwhile, the increase in the proportion of quicklime added could significantly inhibit the leaching of heavy metals. When the pH of the leaching solution was 4, the amount of quicklime added increased from 1% to 5%. The concentration of Mn in the leaching solution decreased from 126.65 mg/L to 4.44 mg/L, a decrease of 96.5%, and the concentration of Mn in the 5% addition group decreased when pH increased to 8. At the same time, the proportion of quicklime addition also had significant effects on Cu, Zn, Pb and Tl. Cu, Pb and Tl decreased by 36.16%, 86.09%, 65.90% and 47.84% in the 5% addition group, respectively, indicating that there were significant differences in the sensitivity of different heavy metals to pH and the stability of sediments.