Thermal and mineral matter transformation behavior of coal ashes in O2/CO2 atmosphere

Two typical coals (sf and xyc) were chosen to be ashed in air and O2/CO2 atmosphere, respectively. These ashes were used to investigate the thermal and mineral matter transformation behavior in O2/CO2 atmosphere. The results show that the chemical compositions of ash produced from different atmospheres are slightly different. Some mineral elements may be carbonated to form carbonate (e. g., calcium carbonate) in O2/CO2 atmosphere during ashing process. The melting endothermic behavior may be inhibited to some extent in O2/CO2 atmosphere at high temperature. As to sf coal, the low temperature eutectic mixtures such as gehlenite are formed in calcium compounds at 950℃ in ashes produced in air atmosphere, which will remarkably decrease coal ash melting point. However, different atmosphere do not affect the transformation behaviors of mineral matter at high temperatures of xyc coal ashes. O2/CO2 atmosphere may inhibit some type of coal fusion to some extent. © 2015, China Coal Society. All right reserved.