Enhancement of Dry Beneficiation of Coal by Air Distributor Design Modification in an Air-Pulsated Stratifier

This study investigated the segregation of organic (maceral) and inorganic (mineral matter or ash) contents of coal in an air stratifier after design modification in air distributor. The optimum angle of fluidization caused by air distributor was found using mathematical formulations of momentum balance on particles, and 30° of angle of fluidization was found to be the optimum angle of fluidization. Using coal feed with 32.64% ash content, the stratification time in the air stratifier with 30° angle of fluidization was estimated using phase distribution studies and the stratification time was found to be 12 min. The time at which concentrate has high organic phase as well as low inorganic phase and, simultaneously at that same time, the reject has high inorganic phase and low organic phase was fixed as the stratification time. Comparative studies with two different coal feeds were done for conventional fluidization and angular (30°) fluidization. The latter was obtained by design modification of air distributor and was found to enhance dry beneficiation of coal in air-pulsated stratifier.