硫酸渣复合球团还原焙烧法制备高品位磁铁精矿

new technology of Composite Pellet Reduction-roasting and Magnetic-separation (CPRM) has been developed for utilization of pyrite cinder, a common by-product in vitriol industry. Pyrite cinder, assaying 45.56% Fe, 0.19% Cu and 1.45% S, was pelletized with the addition of 5% composite agent in balling disc. Green balls after drying were reduced at 700℃～800℃ for 20min with 300kg/t pulverized coal injection in rotary kiln. After two-stage ball-grinding and four stages magnetic separation, magnetite concentrate with iron grade of 66.23% Fe and containing 0.048% Cu and 0.053% S were made. And iron recovery of 73.32%, desulphurization degree of 96.34% and decoppering degree of 74.73% were achieved. Key technique is that composite agent can accelerate reduction of Fe2O3 and transfer copper and sulphur into water-soluble inorganic salts, which were removed during wet magnetic concentration. Using this CPRM technology can fully utilize pyrite cinder and produce high quality magnetite concentrate as iron-bearing feed for steel industry, which will help to solve the pollution of pyrite cinder and extend raw material sourcing for Chinese steel industry.