Effect of purification pretreatment on the recovery of magnetite from waste ferrous sulfate

• Published in: 矿物冶金与材料学报：英文版 Vol. 23; no. 8; pp. 891 - 897
• Main Author: Wang Yu Ying-lin Peng Ya-jie Zheng
• Format: Journal Article
• Language: English
• Published: 2016
• Subjects: 净化处理; 回收率; 废硫酸亚铁; 湿法粉碎; 硫酸亚铁溶液; 磁铁矿精矿; 空气氧化; 预处理工艺
• ISSN: 1674-4799; 1869-103X

The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.