ZINC RECOVERY FROM EAF DUST BY THE IRON REDUCTION DISTILLATION PROCESS

摘要

The iron-reduction distillation process was used to extract zinc from EAF dust. This process consists of two reduction stages. The first stage is the reduction of iron oxide to iron and the second stage is the reduction of zinc oxide by the reduced metallic iron. The effects of operating variables such as temperature, CO/CO_2 gas composition and sintering process on the reduction of iron oxide in the first stage and temperature and pressure (in a nitrogen atmosphere and under vacuum at 2*10~(-3) atm) on the reduction of zinc oxide in the second stage from the EAF dust were investigated. It was concluded that in the first reduction stage, the reduction of iron oxide was promoted by increasing the temperature from 600 to 800°C, and by increasing CO/CO_2 gas ratio from 3 to 9. For the second reduction stage, the reduction of zinc oxide with metallic iron obtained from the first reduction stage was promoted by increasing the temperature from 900 to 1100°C and under vacuum at 2*10~(-3) atm. The zinc recovery was 95%. Greater than 99% of cadmium, lead and chlorine were removed from the EAF dust.