Low temperature ashing: A method to assess the effect of additives on grinding and flotation of coal

In this paper an attempt has been made to study the effect of using chemical additives on grinding and flotation of thermal coal containing 40% ash. The mill products are analyzed by the new technique of low temperature ashing (LT Ash). The LT ash characterization are in excellent agreement with the results of sink float and flotation studies. Triethanolamine and Polyethylene glycol have shown many fold enhancement in fine grinding. However, Triethanol amine selectively grinds gangue in comparison to coal, while Polyethylene glycol enhances selective grinding of coal in comparison to gangue. This is supplemented by the results of flotation. There is an increase in recovery of combustibles from 39% in absence of additive, to 83% in Polyethylene glycol grinding. The flotation product contained ash between 22-25%.