China Nonferrous Metallurgy

Microwave arsenic removal has the technical advantages of fast temperature rise, no heat source gas and no turnover of materials during temperature rise, which is conducive to sintering agglomeration of materials in the furnace. The chemical arsenic phase analysis, thermodynamic calculation, and microwave arsenic-removal agglomeration test were carried out on the secondary zinc oxide dust from zinc smelting. The results showed that the main material phase of arsenic in zinc smelting secondary zinc oxide dust was arsenic(Ⅲ) oxide, and also contained a small amount of high valence arsenic(Ⅴ) oxide, arsenic sulfide and arsenate; and the increase of arsenic removal temperature and the prolongation of arsenic removal time were beneficial to the removal of arsenic from secondary zinc oxide. The thermodynamic analysis of arsenic removal by microwave showed that the arsenic removal reaction mainly occurred at low temperature. The suitable reaction conditions for low temperature microwave arsenic removal test were as follows: microwave arsenic removal temperature 580℃, arsenic removal time 60min and agglomeration temperature 750℃. Under these conditions, the average arsenic content in the final dust agglomeration was 0.87%, the arsenic removal ratio was 89.29%, and the agglomeration ratio was 72.41%. The study is of great significance to improve the technical level of arsenic containing solid waste recycling.