Studies on the characterization of Indian coals using FE-SEM and EDS and its relevance to coal washability

摘要

The basic objective of coal washability is to establish the set of maximum possible separation performance for a given coal feed and to access the cut gravity for achieving clean coal of desired quality. The conventional float-sink (F-S) analysis is time taking, hazardous and at the same time costly. Indian coals are of drift origin and vary widely in the washability characteristics and there is also wide variation from seam to seam at the same mine. The washery is to be fed with coals from multiple sources/seams, which are having wide washability characteristics. The standard practice of washability will not help the washery to improve its performance as a result an alternative online analyzer especially for a commercial coal washing plants which maximize the reliability of actual coal washability in conjunction with particle size distribution, ash, etc is the need of the hour.Researchers worldwide, are trying to establish the washability characteristics of coal through different routes X-ray/gamma, basically imaged based/processing to solve the problem. An automated coal washability analyser is being under developmental stage which will give near realtime F-S data that would maximize the yield at desired ash level and impact positively on the profitability of the plant operation. The results are very promising with the actual standard float and sink data to the coal analysed with the X-ray analyser, which are being highlighted in the present paper.