Abstract: Mechanochemical method was adopted to study the stabilization of Pb in a Pb-containing smelting slag when different stabilizing agents were added. The chemical composition and leaching toxicity of slag were analyzed. The stabilization mechanism of lead in the slag was studied by simulated acid treatment. The effects of four stabilizing additives (iron powder, aluminite powder, hematite and ferrous sulfate) on the leaching toxicity and stabilization rate of lead were examined. The results showed that the promoting effect of four additives on the stabilization of lead followed the order of iron powder > aluminite powder > ferrous sulfate > hematite. The optimum conditions for the stabilization were the amount of stabilizer at 8%(w), mass ratio of grinding media to material 8:1, milling time 1.5 h and milling speed 400 r/min. Under the optimum conditions, the leaching toxicity of lead was 0.258 mg/L and the stabilization rate of lead reached 99.77%. The adsorption of lead ion by the iron oxides on the surface of milled iron particles was the main reason for the decrease of Pb leaching toxicity.

Key words: smelting slag, lead, mechanochemistry, stabilization, leaching toxicity

摘要： 将不同添加剂与含铅冶炼烟气渣混合球磨，采用机械力化学方法研究渣中铅的固定效果，分析了渣的化学成分及浸出毒性，考察了添加剂对铅稳定率的影响，通过模拟酸处理实验研究废渣中铅稳定化机制. 结果表明，添加剂对铅机械力化学稳定性的促进顺序为铁粉>铝粉>FeSO4>Fe2O3. 以铁粉作稳定剂、不锈钢球为球磨介质，废渣中铅稳定化的最佳参数为：稳定剂用量8%(w)、球料质量比8:1、球磨时间1.5 h、球磨转速400 r/min. 该条件下废渣中铅浸出毒性为0.258 mg/L，铅稳定率为99.77%. 酸处理过程中球磨样品中铁粉表面腐蚀产生的铁氧化物对铅离子的吸附是铅浸出毒性降低的主要原因.

关键词: 冶炼废渣, 铅, 机械力化学, 稳定, 浸出毒性