煤在较长一段时间内仍会占据我国能源消费结构的主体地位。随着煤炭的深部开发和开采，势必会遇到更多的侵入体及受其影响的热变煤，但相比于经历深成变质作用形成的煤，热变煤往往具有更高的瓦斯突出风险和自燃风险，从而带来一系列煤炭资源开发和开采过程中的安全问题。另一方面，由于热变煤性质特殊，在现有的煤炭利用工艺条件下，热变煤的利用价值普遍较低。因此，总结归纳热变煤的特殊性质，探讨热变煤潜在的应用价值，既有利于保障煤炭资源的深部开采与开发，也有益于热变煤资源的合理利用。在世界范围内，热变煤分布广泛，主要采煤国均有与热变煤相关的报道。自十九世纪中叶首次报道热变煤至今，国内外众多学者对热变煤的煤岩学、地球化学、矿物学等领域进行了大量的研究。基于此，本文归纳了热变煤在煤岩、矿物、元素、成熟度、生烃潜力、同位素、光学、孔隙、大分子结构等方面的特殊性质，并探讨了引起热变煤特殊性质的地质影响因素。结合热变煤的研究进展，提出了热变煤潜在的发展方向。基于热变煤化学结构变化特征，指出了热变煤是制备碳材料潜在的优良原材料。而热变煤中丰富的孔隙结构，加之岩浆岩侵入体普遍具有良好的封闭性，在适当的地质条件下热变煤会形成良好的煤层气储层。

Coal will still occupy the dominant position in energy consumption structure of China for a long time. The deep development and mining of coal will inevitably encounter more igneous intrusions and thermally altered coal affected by them.Comparing with plutonic metamorphosed coal, thermally altered coal is more likely to bring risks of gas outburst and spontaneous combustion, and it will probably bring a series of safety problems during the development and mining processes of coal. On the other hand, due to the special nature of thermally altered coal and existing technological conditions, the value of thermallyaltered coal is limited. Therefore, summarizing the special properties and exploring the potential application of thermallyaltered coal are not only helpful to the deep mining of coal, but also beneficial to the utilization of thermallyaltered coal. Thermally altered coal is distributed worldwide, and relevant reports are made by many coal mining countries. Since thermally altered coal was firstly reported in the mid 1800s, a lot of researches about the coal petrology, geochemistry, mineralogy, etc. have been done. Basing on these literatures, this review summarized specific properties of thermally altered coal from the aspects of coal petrology, minerals, elements, maturity, potential of hydrogen generation, isotope, optical properties, porosity, macromolecular structure, etc., and discussed the factors affected thermally altered coal.According to the specific properties of thermally altered coal, especially the chemical structure, a possible future development of thermally altered coal was also proposed in this work, i.e., thermally altered coal may be a potential feedstock for preparing carbon materials.The abundant pore structure of thermally altered coal, coupled with the good seal of igneous intrusion and proper geological conditions, will probably make thermally altered coals to be good coal bed methane reservoirs.

0 引言

1 热变煤地球化学特征

   1.1 元素地球化学特征

   1.2 有机地球化学特征

2 煤岩学特征

   2.1 光学特征

   2.2 煤岩孔隙结构特征

3 化学结构特征

4 影响热变煤结构演化的因素

5 热变煤研究中存在的科学问题

6 热变煤开发利用建议

7 结语