Combustion characteristics of fine- and micro-pulverized coal in the mixture of O₂/CO₂

The effects of oxygen concentration, particle size, and heating rate on the coal combustion characteristics under an O₂/CO₂ atmosphere were investigated. The results indicated that the oxygen concentration played the most important role. As the oxygen concentration increases, the ignition and burnout temperatures decrease and the comprehensive combustion property index S increases. Moreover, the improvement of the oxygen concentration intensified the effects of the other factors. The ignition mechanism changes from hetero-homogeneous type to homogeneous type as the oxygen concentration increases. The ignition and burnout temperatures decrease slightly as the mean particle size decreases, and the index S increases measurably as the mean particle size decreases. The heating rate has different effects on the ignition temperature, burnout temperature, and index S at different oxygen concentrations.