Development of Moisture and Ash Based Correlation for the Estimation of Mineral Matter in High Ash Indian Coal

Abstract

The experimental determination of mineral matter in coal is a tedious as well as time consuming process, and requires highly skilled analyst to carry out the chemical analysis of coal and ash. On the other hand, determination of moisture and ash is relatively easy using moisture oven and muffle furnace and can be determined anywhere with little care. Most of the methods reported till date for the evaluation of mineral matter in coal involves indirect determination of mineral matter using high temperature ash as one parameter. All these methods offer conversion of ash yield into mineral matter with the help of correlations based on certain assumptions. Although, the method for direct determination of mineral matter by chemical analysis is also reported, but is of little use as it requires extensive chemical analysis. In this study mineral matter is determined directly by oxygen plasma asher in coal samples collected from different regions of India. The results obtained were compared with those obtained by existing correlations. It has been observed that all the existing correlations including Parr’s, are found to be unrealistic for high ash Indian coal. An attempt has been made to develop a new correlation for the estimation of mineral matter based on two simple parameter i.e. moisture content and ash yield. Present model was developed after analyzing 75 coal samples. The developed correlation appears to be more simple and better and is represented as Mineral Matter(MM)= 0.74(Moisture) + 1.17(Ash)