Fine coal dewatering using high airflow

Fluidized bed drying is currently receiving much attention as a dewatering option after the beneficiation of fine coal. Apart from concerns about safety and combustion, the operating costs can be high if very high gas or air temperatures are used. The aim of this study was to investigate the removal of moisture from fine coal by using air at a lower temperature (25°C − 40°C) within a controlled environment by lowering the relative humidity of air. It was firstly proven that fluidization has a major advantage over normal static beds when allowed to reach equilibrium. Hereafter, several parameters that influence the dewatering rate and final moisture content were tested, from which it was concluded that the relative humidity of air acts as the largest driving force for dewatering. It was, therefore, shown that this is a viable technology for the dewatering of fine coal