高温下煤中矿物质对气化反应的影响

利用XRD对1100℃~1500℃高温下矿物质在弱还原气氛中的变化进行考察，并利用RIR对矿物质进行半定量分析，发现随着温度的升高莫来石含量增大，而SiO₂含量下降，符合SiO₂-Al₂O₃二元相图的变化。高温下部分无定形矿物质发生熔融，主要为硅铝酸盐。在煤焦二氧化碳气化过程中，熔融的硅铝酸盐与煤焦表面接触阻碍气化反应进行。利用FT-IR测定了硅铝酸盐结构的变化，说明高温下矿物质对气化反应的影响与硅铝酸盐的聚合程度存在一定的关系。

Influences of mineral matter on high temperature gasification of coal char

X-ray diffraction (XRD) was performed to analyze the mineral matter in coal ash from 1100℃ to 1500℃, with an interval of 50℃. Relative Intensity Ratio (RIR) method was used to calculate the content of each crystalline in coal ash. The amount of mullite increases with elevated temperature but that of SiO₂ decreases. The transformation of mullite and SiO₂ accords well with the binary phase diagram of SiO₂-Al₂O₃. At high temperature, the amorphous mineral matters, mainly, aluminosilicates melt above ash softening temperature. During CO₂ gasification at high temperature, the carbon conversion is hindered by the aluminosilicates melts, which cover the surface and block the pores of coal particles. Because of the short and ordered sequence of melts, FT-IR analysis was taken for the melts in coal ash after gasification. The structure alteration of aluminosilicates influences the surface tension of melts, which determines the interaction between coal particles and aluminosilicates.