煤中主要外在矿物质在O_2/CO_2气氛中的迁徙转化

Transformation of Main Excluded Mineral Matter in Coal in O_2/CO_2 Atmosphere

以煤中几种典型外在矿物的纯矿物及其混合矿物为研究对象，比较分析了空气气氛和O2／CO2气氛下黄铁矿、高岭石和方解石，以及黄铁矿和方解石含量高的易熔融混合矿物和高岭石含量高的难熔融混合矿物的热转化行为。研究结果表明，O2／CO2气氛下黄铁矿和高岭石的热转化行为与空气气氛并没有明显不同，但O2／CO2气氛下黄铁矿在氧化过程中会有少量中间产物磁铁矿生成。CO2的存在对方解石的转化影响较大，会使方解石的分解温度延迟160～180℃左右。在O2／CO2气氛下，混合矿物的热转化行为并不是单个矿物转化行为的简单叠加，高温时矿物质之间的相互作用更加明显，易于形成低温共熔物钙硅铝酸盐类物质，从而更容易促进矿物的熔融，结渣倾向更明显。

Base on several typical pure excluded mineral matters in coal and its mixed minerals, the thermal behaviors of pyrite, kaolinite, calcite and two different mixed minerals were investigated in air and O2/CO2 atmospheres. These two mixed minerals, one of them contained higher proportion of pyrite and calcite, and another contained higher proportion of kaolinite. The results show that the thermal behaviors and final products of pyrite and kaolinite are not affected by O2/CO2 atmospheres. However, there are a few part of magnetite as an intermediate low temperature product during pyrite transformation. The presence of high CO2 concentration in surroundings, which make the decomposition temperature of calcite delay by about 160-180 ℃. In O2/CO2 atmosphere, the thermal behaviors of individual minerals cannot model the thermal behaviors of mixed mineral matters. At high temperature, the interaction between mineral and mineral is more obvious in O2/CO2 atmosphere than that in air atmosphere. Meanwhile, more low temperature eutectic salts （calcium aluminosilcate） are produced, which makes it easier to promote mineral matters melting and make slagging tendency be more pronounced in O2/CO2 atmosphere.