- Padmesh gupta say Problems associated with Indian run-of-mine coal. Indian coal has drift origin, resulted in intimate mixing of mineral matter with coal, giving rise to the ash content.
- According to Mr. Padmesh Gupta the coal-ash distribution in the coal matrix in Indian coal is so interwoven that coal is essentially required to be crushed to small sizes for affecting liberation of coal and ash particles.
- Coal beneficiation largely depends on gravity difference of coal and ash particles.
- The Near Gravity Material (NGM) at any specific gravity of cut is high, which means at any specific gravity of cut there is quite good amount of misplacement of coal towards sink and vice versa.
- It further put hurdle to achieve sharp separation during coal washing
Coal Washing Technological Options-Padmesh Gupta
- As Padmesh Gupta say Clean coal technology being practised in coal washeries in India, as pre combustion clean coal technology, mainly focus on cleaning of coal by removing ash from coal.
- Earlier only coking coal was being washed because steel making needs coking coal of ash of 17 to 18%. The raw coal ash in Indian coking coal varies from 25 to 30%. Now-a-days, Min. of Environment & Forests has put restriction on the use of high ash coal in power sectors, which necessitated priority to wash non-coking coal also.
- Padmesh Gupta Say the choice of process equipment involved in coal washing depends on factors such as the type of coal being treated, the market requirement and the economics