O2/CO2气氛下高温煤灰热行为及其矿物相转化规律

对2种典型的煤样分别在空气和O2/CO2气氛下制取高温灰，并对此高温灰在不同气氛下的热行为及其在高温下矿物相的转化特性进行了研究。结果显示，煤粉在不同气氛下得到的高温灰，其化学成分随着气氛的变化略有不同。O2/CO2气氛下获得的高温灰，煤灰中一些含钙矿物元素易于发生碳酸化，形成较多的碳酸钙等碳酸盐。对于钙铁矿物含量较高的神府煤，在O2/CO2气氛下形成的煤灰高温下的蒸发熔融吸热较少；而在空气气氛下，在950 ℃的较低温度下便形成钙黄长石等易形成含钙低温共熔混合物的矿物相，其熔融行为在较低温度下发生。对于硅铝含量较高的西阳村煤，O2/CO2气氛下形成的煤灰高温下的蒸发熔融吸热也较少，但气氛的改变不会影响高温下矿物相的形成。O2/CO2气氛可以明显的抑制钙矿物含量极高煤灰的熔融结渣行为。

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.