电石渣稳定锌冶炼浸出渣中可溶性重金属研究  

Study on Stabilization of Soluble Heavy Metals in Zinc Smelting Leaching Slag with Calcium Carbide Slag

作　　者：黄祥 陶逸倩 韩雨岐 雍毅 佟洪金 龙泉 尹朝阳 HUANG Xiang;TAO Yiqian;HAN Yuqi;YONG Yi;TONG Hongjin;LONG Quan;YIN Zhaoyang(Sichuan Academy of Eco-Environmental Sciences,Chengdu 610041,China;Sichuan Key Laboratory of Pollution Control for Heavy Metals,Chengdu 610041,China;Sichuan Environmental Protection Engineering Centre of Solid Waste Treatment&Disposal,Chengdu 610041,China)

机构地区：[1]四川省生态环境科学研究院,四川成都610041 [2]四川省环境保护重金属污染防治重点实验室,四川成都610041 [3]四川省环境保护固体废物处理处置工程技术中心,四川成都610041

出　　处：《环境科学研究》2025年第2期395-406,共12页Research of Environmental Sciences

基　　金：四川省科技厅重点研发计划项目(No.2021YFS0287);四川省生态环境科学研究院科技创新项目(涉重危废中多种重金属稳定化药剂研究开发)。

摘　　要：锌冶炼浸出渣中可溶性重金属的稳定化是实现其全过程污染控制和安全利用处置的关键措施之一,目前能够实际应用的稳定化药剂仍然十分有限。采用电石渣、氧化钙和氢氧化钙开展不同条件下的稳定化试验,并结合重金属形态研究和XRD、SEM-EDS等表征手段,探究电石渣对锌冶炼浸出渣中Zn、Cd、Mn三种高可溶性重金属的稳定化效果、作用机制及应用前景。结果表明:在添加比高于5%(质量比)时,电石渣等碱性药剂对浸出渣中可溶性重金属Zn、Cd、Mn具有良好的稳定化效果,3种重金属浸出毒性削减率均在99%以上,Zn浸出毒性低于1 mg/L,Cd、Mn浸出毒性均低于0.3 mg/L,均低于《危险废物填埋污染控制标准》(GB 18598-2019)标准限值。这种稳定化作用主要发生在酸性浸提阶段,通过浸出液pH的上升去除浸出液中的重金属离子;碱性药剂对浸出渣中铁酸锌(ZnFe_(2)O_(4))颗粒的包裹和附着作用也能对可溶性Zn、Cd、Mn产生少量残渣态转化效果;这种稳定化过程会大幅降低浸出渣中硫酸铅晶体的含量,同时生成新的硫酸钙晶体,这种硫酸铅向铅碱性化合物的转化可能增加铅的酸性溶出风险。电石渣用于浸出渣的稳定化仍然存在提高固废pH、增加铅的酸性溶出风险,以及在pH≤2的淋溶条件下出现重金属浸出毒性大幅上升、稳定化作用失效等问题。在实际应用中,建议采用具有不同稳定化机制的药剂实现协同控制,同时关注高酸度淋溶条件造成的稳定化失效问题,防范浸出渣稳定化填埋存在的潜在环境风险。The stabilization of soluble heavy metals in zinc smelting leaching slag is one of the key measures to achieve pollution control and safe utilization or disposal during the entire process.At present,there are very few stabilizing agents that can be used practically.To investigate stabilization effect and application prospects of the calcium carbide slag on highly soluble Zn,Cd and Mn in leaching slag,stabilization experiments were conducted under different conditions using carbide slag,calcium oxide,and calcium hydroxide in this study.Heavy metals forms research and characterization methods such as XRD and SEM-EDS were used to investigate the stabilization mechanism of calcium carbide slag.The results showed that when the added amount of alkaline agents such as carbide slag was higher than 5%(mass ratio),it had a good stabilizing effect on soluble heavy metals Zn,Cd and Mn in leaching slag.The leaching toxicity reduction rates of Zn,Cd and Mn in the stabilized leaching slag were all above 99%.The leaching toxicity of Zn was below 1mg/L,and that of Cd and Mn was below 0.3 mg/L,all of which were lower than the China National Standard Limit of Pollution Control Standard for Landfill of Hazardous Waste(GB 18598-2019).The stabilization of calcium carbide slag mainly occurred during the acidic leaching process,removing heavy metal ions from the leaching solution through the increase of pH value.A weak residual state transformation on soluble Zn,Cd and Mn of alkaline agents was also found from encapsulating and adhering zinc ferrite(ZnFe_(2)O_(4))particles in leaching slag.The stabilization process of carbide slag was found significantly reducing the content of lead sulfate crystals in leaching slag,while generating new calcium sulfate crystals.The conversion of lead sulfate to lead alkaline compounds might increase the risk of lead leaching under acidic conditions.There are some problems in the stabilization of leaching slag by carbide slag,including increasing the pH of solid waste and the risk of lead leaching under

关 键 词：电石渣 浸出渣 可溶性重金属 稳定化 

分 类 号：X741[环境科学与工程—环境工程]