赤铁矿表面磁化研究

Surface Magnetization of Hematite in Pulp

采用空气氧化法在矿浆中直接合成磁性Fe3O4粒子,从而达到表面磁化弱磁性赤铁矿的目的。考察了药剂用量、反应时间、溶液温度等因素对磁化的影响,结果表明,温度是影响磁化效果的重要因素,50℃可视为磁化反应能否快速进行的临界温度。Fe2+离子浓度为0.012 mol/L,氨水浓度为0.15 mol/L,在50℃下磁化反应10 min后,赤铁矿磁选回收率由磁化前的68.0%提高到95.2%。使用振动样品磁强计(VSM)和扫描电镜对磁化前后的赤铁矿进行了表征,结果表明,赤铁矿磁化后的比磁化率大于磁化前,饱和质量磁化强度由磁化前的0.694 emu/g增加到1.415 emu/g;可观察到磁化后的赤铁矿表面有微细颗粒Fe3O4晶粒覆盖。

Surface magnetization of hematite in pulp with synthetic magnetic Fe304 particles was studied. Magnetic Fe3 O4 particles were formed by air oxidation method in pulp and were coated on the surface of hematite. The effects of concentration of ammonia, reaction time and pulp. temperature on the surface magnetization of hematite were investigated. The results show that temperature is a dominant tactor affecting the surface magnetization. At the pulp temperature of 50 ℃ for reaction of 10 minutes by adding Fe （ 11 ） 0. 012 moL/L and ammonia 0.15 moL/L, the surface magnetization of hematite was achieved with a recovery of 95.2% by magnetic separation in comparison with a recovery of 68% without surface magnetization. Vibrating sample magnetometer （VSM） and scanning electron microscopy （SEM） were used to characterize the hematite before and after the process. The results confirmed that the specific magnetism of hematite increased after the process of magnetization as the magnetic moment per unit mass increased to 1. 415 emu/g from 0. 694 emu/g, also ultrafine magnetic particles were observed coating on the surface of hematite.