Recovery of Iron from Lead Slag with Coal-Based Direct Reduction Followed by Magnetic Separation

摘要

Iron recovery from a lead slag in Henan province was carried out with the technique of coal-based direct reduction followed by magnetic separation. Scanning electron microscopy (SEM) was used to investigate the transformation of iron-containing minerals and the particle size of metallic iron generated by coal reduction. The results showed that technique is feasible for iron recovery from the lead slag. Under the conditions of weight ratio of slag: coal: CaO as 50:15:5, the roasted temperature of 1250 °C for 45 min, and then two stage of grinding and twice magnetic separation, the metallic iron powder was obtained with the iron grade of 92.85% and iron recovery of 92.85%. The iron-containing minerals in the forms of hercynite, fayalite and maghemite were mianly transformed into metallic iron and the particle size of metallic iron was more than 50μm. Therefore, the metallic iron in roasted product can be dissociated by coarse grinding and further was separated by magnetic separation to recover the metallic iron.