Development of Coal Washability Index: A Case Study on The ALBORZ_E_SHARGI Coal Washing Plant Wastes

Evaluation of gravity separation of minerals usually is accomplished with two indices. The first is liberation degree and the second is separation accuracy or Escort Probable (Ep). This research is a case study on ALBORZ_E_SHARGI coal washing plant wastes for the evaluation of two essential indices. It was found that the indices representing a numerical value cant give sufficient information required for decision. Thus efforts took place to improve previous indices and to represent a method for accurate characterization of feed. It was obtained a suitable product for steel industry in two stages. Gravity concentration step by cut point of 1.75 t/m3 is necessary to produce primary concentrate followed by grinding it to -2mm and rewashing to obtain final concentrate. In the first step ash content reduced from 66% to 31.3% and the reduction of ash content to 14% in final washing was possible.