Mechanism and application of coal dry beneficiation with air-dense medium fluidized bed

Abstract

The mechanism of beneficiation with air-dense fluidized bed has been theoretically studied in the paper. Focusing attention on the misplacing resources in separation process, the misplacing effects are divided into two parts called respectively as misplacing effect of viscosity and misplacing effect of motion. The proposed separation theory can reasonably explain the results of separation in different fluidization states. Experimental results in pilot and commercial plants showed that the air-dense medium fluidized bed is a high efficiency dry cleaning technique. The dynamic stability of fluidized bed density is directly affected by the variation of fine coal content in fluidized bed and can be controlled in expected range through measurement of fluidized bed density and adjusting of splitflow rate. With air-dense medium fluidized bed, various coals of size 50–6 mm can be efficiently beneficiated. The separation density can be adjusted between 1.2–2.2 g/cm3, and the probable error Ep value is about 0.06.