含砷废渣固化处理技术研究进展

Research progress on solidification treatment technology of arsenic-containing waste residues

目前冶炼厂产生的大量含砷烟尘及废水90%以上被转化为固体废物,形成含砷废渣。由于缺乏合适的处理方法或处理和处置成本高等原因,砷渣的无害化处理与综合利用受到限制。含砷废渣的固化是目前较好的一种处理方式,主要技术有水泥固化、地聚物固化和矿渣固化等。水泥固化是一种比较成熟且使用最广泛的技术,但固化体长期稳定性不好,砷离子易浸出;地聚物材料来源广,固砷效果较好,但常需要高温条件,能量消耗大;矿渣胶凝固砷基本可以实现水泥“零添加”,减少水泥的使用,降低能耗,是目前单一固化技术最好的选择。通过对文献进行比较分析可知,一种固化技术很难对含砷废渣进行大容量、持久的固封,三种技术联合使用效果较好。目前水泥固化和地聚物固化的机理都尚未形成标准,矿渣固化机理已有较为明确的研究成果,后期还需要加强联合技术固化机理及工艺探究,同时进一步评估固化材料的环境风险。

At present,more than 90%of the arsenic-containing dust and wastewater produced by smelters are converted into solid waste,forming arsenic-containing waste residue.Due to the lack of appropriate treatment methods or high cost of treatment and disposal,the harmless treatment and comprehensive utilization of arsenic slag are limited.The solidification of arsenic-containing waste residue is a good treatment method at present.The main technologies include cement solidification,geopolymer solidification and mineral residue solidification.Cement solidification is a relatively mature and most widely used technology,but the long-term stability of the solidified body is not good,and arsenic ions are easy to leach;geopolymer has a wide source of materials and a good arsenic fixation effect,but it often requires high temperature conditions to consume a lot of energy;the solidification of arsenic by mineral residue adhesive can basically achieve‘zero addition'of cement,reduce the use of cement and reduce energy consumption.It is the best choice for single curing technology at present.Through the comparative analysis of the literature,it can be seen that a solidification technology is difficult to carry out large-capacity and long-lasting sealing of arsenic-containing waste residue,and the combined use of the three technologies is better.At present,the mechanism of cement solidification and geopolymer solidification has not yet formed a standard,and the mechanism of mineral residue solidification has been clearly studied.In the later stage,it is necessary to strengthen the mechanism and process of joint solidification technology,and further evaluate the environmental risk of solidified materials.