Chemical Beneficiation of Low Grade Coal - A Review

Abstract

India is having large reserves of low grade coals. The use of low-grade coal in various industries like power plants, metallurgical plants, cement units etc. leads to environ-mental pollution because of generation of large amount of solid and gaseous pollutants. Therefore, it is of impor-tance paramount to clean the coal before its utilization. There are a number of upgrading technologies to produce clean coal. The current paper reviews demineralization aspects by physical and chemical beneficiation of high ash and/ sulfur containing coal.Physical beneficiation of coal is not very effective in separation of the finely dispersed minerals, whereas chemical beneficiation uses expensive reagents and leads to generation of large amount of waste-water which needs to be purified before discharge. Thus, a combined approach consisting of physical and chemical cleaning of coal appears to have a potential for. signifi-cant reduction of ash with less investment while generat-ing less polluting wastewater.