IRON RECOVERY FROM RED MUD BY REDUCTION ROASTING-MAGNETIC SEPARATION

摘要

This work provided an effective method for comprehensive utilization of red mud, which mainly focused on the first step of recovering iron from a high iron content red mud by reduction roasting-magnetic separation. During the reduction,iron oxides were reduced to metallic iron with the aid of sodium sulfate and sodium carbonate. Effects of the dosages of sodium sulfate and sodium carbonate, roasting temperature and roasting time on the metallization ratio of iron of roasted product, total iron grade and iron recovery of magnetic concentrate were primarily investigated. In the presence of 6% Na_2SO_4, 6% Na_2CO_3 and optimal reduction roasting-magnetic separation conditions: roasting temperature of 1050 ℃, roasting time of 60 min, magnetic separation feed fineness of 90% passing 74 μm and magnetic field intensity of 0.1 T, a magnetic concentrate containing 90.12% iron with iron recovery of 94.95% was obtained from a red mud containing 48.23% total iron, 7.71% Al_2O_3 and 7.69% SiO_2.