China Nonferrous Metallurgy

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.