Zhengqi Guo
Central South University, China
Title: Reduction-volatilization behaviors of Fe, Pb and Zn during the updraft pre-reductive sintering process of zinc-bearing wastes
Biography
Biography: Zhengqi Guo
Abstract
Zinc-bearing dust was generated in the steel industry from iron and steel companies, which contains many valuable and haezardous elements, such as iron, zinc and lead. Currently, approximately 40 million tons of Zinc-bearing dust is estimated to be produced and dumped in the China annually, resulting in rescoruce wastes and potentially damages to the ecological environment. It is therefore extremely urgent to develop appropriate technology for comprehensive utilization of dust from both economic and environmental perspectives. In our previous papers, an innovative process of updraft pre-reductive sintering process was proposed to treat Zinc-bearing dust. Thus, to better understand the mechanism of redution and volatilizaiton behaviors of Fe, Pb and Zn in the new process, in this study, an investgate on reduction kinetics of realted oxides in the Zinc-bearing dust was conducted by simulating pre-reductive sintering process. The results show that the reactions are controlled by chemical reaction, and the calculated activation energier are 43.88 and 72.33KJ.mol-1, respectively, for the reductions of iron oxides and ZnO. Meanwhile, the reducing reaction of PbO is controlled by gas diffusion and its activation energy is determined as 18.22KJ.mol-1. Based on the dynamic analysis, high temperature and strong reduction atmospher is beneficial to reduciton of iron oxides and removal of Pb and Zn.