Influence of band thickness of banded hematite quartzite (BHQ) ore in flotation

Hematite and quartz present in banded iron ore are intimately associated with one another and require fine grinding for the liberation of mineral particles. The influence of the thickness of bands on the liberation and flotation response of banded hematite quartzite (BHQ) ore is investigated. A computer program is developed to predict the liberation of banded iron ores based on different patterns of banding. It is found that the phase which is distributed in thick bands is better liberated compared to thin bands. QEMSCAN studies on BHQ samples have shown similar trends. The direct and reverse flotation behavior of the BHQ ore using oleic acid and dodecylamine respectively was determined. In reverse flotation, 64.4% Fe at 59% recovery could be obtained from an ore having thick quartz bands, whereas under identical conditions, only 60.6% Fe at 64.8% recovery could be obtained with thin bands. In the case of direct flotation, it is possible to achieve 63.8% Fe at 50.7% recovery for the ores with a thick quartz band and 62.7% Fe at 58.1% recovery for the thin band.