Effect of active pulsing air flow on gas-vibro fluidized bed for fine coal separation

•A gas-vibro fluidized bed was proposed for fine coal beneficiation.•Stationary and ergodic tests methods were proposed for a gas-vibro fluidized bed.•Effect of pulsation frequency on bed density was investigated.•Efficiency of fine coal separation can be modified observably.

Coal is one of the primary energy sources in the world. Heavy consumption of coal causes severe environmental problems such as acid rain, fog, and dust. Because of increasingly severe water shortage, it is urgent to develop efficient dry separation methods. Air-dense medium fluidized beds (ADMFB) have been studied for dry beneficiation in the last decades. In this study, a pulsing air flow was introduced into ADMFB to form a gas-vibro fluidized bed (GVFB). The bed density of GVFB showed a stationary random signal with ergodic property. Using the vibration energy of an air flow, the fluidization quality and stability of bed density were enhanced. The bed density was suitable for fine coal separation in the middle-frequency region. The separation tests indicated that the effect of pulsing air flow is significant at a low gas speed, and the GVFB achieved effective separation and improved the quality of fine coal.

Graphical AbstractDownload high-res image (90KB)Download full-size image