Recovery of iron values from waste mine dumps by gravity concentration methods

Abstract

The Sandur area in Bellary district, Karnataka, is endowed with rich deposits of high-grade iron and manganese ores. Extensive mining has been taking place in this area for several decades now. It is estimated that about 6 million tonnes of material containing iron values ranging from 35-65% Fe is being dumped as waste. The waste dumps in turn are washed away during the rainy season and are permanently lost in the valleys and streams. Though, this loss has been taking place since mining began no attempt has been made to prevent it and to recover iron values from the dumps. These waste dumps contain high amount of alumina and silica and need processing. In the present investigation an attempt has been made to recover iron values by gravity methods as they are cheap, efficient and environment friendly. The waste dumps, collected from the different mine sites of VESCO mines of Sandur area, analysed 49-55% Fe, 6-8% Al2O3, and 4-7% SiO2. Jigging and Tabling experiments with different parameters were carried out to reduce the impurities present in the dumps. It has been found that the dumps can be improved by gravity concentration methods. The results obtained by various experiments show that the iron values increased by 7 to 10% with 79% recovery with the significant reduction of alumina and silica.