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

• Published in: International journal of minerals, metallurgy and materials Vol. 23; no. 8; pp. 891 - 897
• Main Authors: Yu, Wang, Peng, Ying-lin, Zheng, Ya-jie
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.08.2016; Springer Nature B.V; School of Metal urgy and Environment, Central South University, Changsha 410083, China%School of Chemistry and Environmental Engineering, Hunan City University, Yiyang 413000, China
• Subjects: Calcium hydroxide; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Corrosion and Coatings; dioxide;purification;magnetite;magnetic; ferrous; Glass; Gypsum; Impurities; Iron sulfates; Magnetic separation; Magnetite; Materials Science; Metallic Materials; Natural Materials; Oxidation; Precipitators; Pretreatment; Purification; Recovery; separation; Slaked lime; Sodium hydroxide; sulfate;titanium; Sulfates; Surfaces and Interfaces; Thin Films; Tribology; ferrous sulfate; magnetic separation; magnetite; titanium dioxide; purification
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-016-1304-2

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.