Effective processing of iron ore slime using column flotation

Abstract

Indian iron ores slimes are generally rich in iron content. The presence of high alumina and silica in the iron ores reduces the grade and poses difficulty in processing. Due to fine granulometry and mineralogical complexity, processing of iron ore slimes by conventional physical separation methods such as gravity and magnetic separation, has limited success. Froth flotation is a versatile method used in mineral processing to remove the impurities from the fine ore. The iron ore slime containing 58.7% Fe, 5% SiO2 and 4.88% Al2O3 was used for this investigation. Column flotation was used as it is a better alternative for processing of iron ore slimes. Tests were conducted at alkaline pH using sodium oleate as a collector and MIBC as frother. A factorial design of experimental approach was followed taking three variables namely froth height, superficial air velocity and collector dosage. The interaction effects of variable parameters on recovery and Fe grade of concentrate were studied. The relationship between residence time of air in froth zone and recovery was also studied.