Magnetizing roast and magnetic separation of iron in rare-earth tailings

• Published in: Journal of Central South University 2016-08, Vol.23 (8), p.1899-1905
• Main Authors: Yang, He, Rong, Yi, Han, Chong, Tang, Rong, Xue, Xiang-xin, Li, Yong, Li, Ying-nan
• Format: Article
• Language: English
• Subjects: Chemical and Environmental Engineering; Engineering; Magnetic separation; Materials; Metallic Materials; Metallurgy
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-016-3245-3

Magnetic separation of iron in rare-earth tailings was achieved by magnetizing roast process with coal as reductant. Effects of the temperature, carbon to oxygen ratio, and cooling type on magnetic susceptibility and composition of rare-earth tailings were investigated. The results show that roast conditions with the temperature of 650 °C, carbon to oxygen ratio of 3.85, and holding time of 2.5 h are in favor of reduction of Fe 2 O 3 to Fe 3 O 4 when the roasted rare-earth tailings is cooled along with furnace. Under these roast conditions, magnetic susceptibility of rare-earth tailings is 2.36 that is very close to theoretical value (2.33). However, magnetic separation results of iron in rare-earth tailings cooled along with furnace are not satisfactory. Through comparing magnetic separation results of iron in rare-earth tailings cooled by different ways, it is found that water cooling is more favored of magnetic separation of iron in the roasted rare-earth tailings than furnace cooling and air cooling. Grade and recovery of iron in concentrate from rare-earth tailings cooled by water are 45.00%-49.00% and 65.00%-77.50%, respectively.