Separation characteristics of 100-mm dual-cone water-only cyclone to wash high NGM coal

Abstract

ABSTRACTExperiments were carried out on a 100-mm laboratory water-only cyclone with dual-type cone to treat −3.0-mm Indian coal. Separation behavior of the individual size fractions (within −3 + 0 mm size) feed coal during separation was analyzed critically and their cut densities (SG50) were estimated. A minimum ash content of down up to 18% from a feed ash of 28.7% is possible with an appreciable yield of 49.3% for the coal below 3 mm size range. While analyzing the results of yield and ash percentages for separation of bulk coal fraction (−3.0 + 0.075 mm size) and the fines fraction below (0.075 mm size), it was found that the ash reduction achieved for the coarse coal were very high when compared to the fines. Further, attempts made to predict the performance of the cyclone using the concept of generalized distribution curve revealed that the Plitt’s equation can be conveniently adopted. This equation can be given as for separation of bulk coal. Further, it was established that, besides the outlet diameters of cyclone, the presence of fines below 0.075 mm in the feed influences the throughput of slurry of the cyclone significantly given as .