A novel dry beneficiation process for coal

Abstract

ABSTRACT More than two-thirds of coal in China is present in dry areas and cannot be separated by traditional wet coal preparation techniques. Dry coal beneficiation is an effective technique to realize coal separation and upgradation, as it does not consume water, has a low cost and is pollution-free. In this study, an air dense medium fluidized bed (ADMFB) and FGX separator were arranged in series to achieve 100–0 mm coal size dry separation. Raw coal (100–50 mm and 50–0 mm) was separated by ADMFB and the FGX separator, respectively. The fluidization characteristics of ADMFB and the separation effect were analyzed. When the gas velocity was 0.11 m/s, the yield of clean coal was 90.96% with an ash content of 7.86%. With respect to the FGX separator, the coal transport process and the distribution of the ash segregation degree under different vibration parameters were studied. The separation effect was optimal when the vibration amplitude reached 2.2 mm and the vibration frequency was 18 Hz. The clean coal yield was 90.30%, and the ash content was 13.28%. Effective coal separation (100–0 mm) was first achieved by the combined ADMFB–FGX separator separation system.