Comprehensive Treatment of the Secondary Pyrite Tailings by Oxidizing-Reducing Roasting

Comprehensive treatment of the secondary pyrite tailings was realized by using a oxidizing-reducing roasting technological flowsheet.The effects of some factors,such as the gas velocity,the temperature and time of roasting on results of sulphur-removal and arsenic-removal were examined.The results showed that the two-stage oxidizing roasting technology is suitable for eliminating S and As.When the temperature of the oxidizing roasting reaches 600～750℃,the grade of Fe reaches more than 64% after treatment.Then,under the temperature of 1100℃,by means of reducing roasting to recover several valuable metals,such as Sb,Pb,In and Zn.In the end,the grade of Fe reaches more than 66% in the cinder,which can be used as a fine iron-making raw material.