Role of recovery sieve size in upgrading of fine coal via oil agglomeration technique

Abstract Although recovery sieve size has vital importance for the success of the oil agglomeration technique for upgrading of fine coals, its effect on the process has been generally omitted in previous studies. Therefore, the present study was undertaken to fill the gap in this area and draw attention to the importance of recovery sieve size. An oxidized fine coal sample was subjected to oil agglomeration process and effect of separation sieve size on the success of the process with regard to combustible recovery and ash–sulphur rejection was investigated. 72.90% of ash, 90.90% of pyritic sulphur, and 87.75% of sulphate sulphur were removed from the coal with combustible recovery of 76.53%. Increase in recovery sieve size had positive effect on removals of ash and sulphur. Recovery sieve size was found to be extremely important for the performance of the process in that combustible recovery reduced sharply with increasing sieve sizes. It was concluded that recovery sieve size should be the same size with the top feed size.