Separation performance of raw coal from South Africa using the dense gas-solid fluidized bed beneficiation technique

The separation performance of a raw coal sample from South Africa based on the dense gas-solid fluidized bed beneflciation technique was investigated. Analysis showed that the raw coal sample distributes mainly in the -50+6 mm size range with the -1.6 g/cm(3) density fraction accounting for 78.20% of the cumulative mass distribution. A flow sheet of the sequential coal beneficiation technique was introduced. The experimental and simulation results of the hydromechanical and density distribution stability indicate that the dense gas-solid fluidized bed could provide a stable separation environment with uniform density fluctuations under suitable operating conditions. With the application of this technique on the raw coal sample, the separation results show that three products, consisting of 73.25% clean coal with an ash content of 9.59%, 11.31% middlings, and 15.44% gangue were effectively separated at two different densities of 1.82 g/cm(3) and 1.57 g/cm(3). This study provides an effective flow sheet for achieving the high-efficiency separation performance on raw coal from arid areas.