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煤层自燃是一个复杂的物理、化学和环境作用过程,是多种内在原因和外在条件综合作用的结果.本文分析了内蒙古乌达矿区煤层自然发火的内在原因和外在条件,揭示了煤层自燃的各种控制因素.影响煤层自燃的内在原因包括煤层厚度、变质程度、灰分含量、发热量、硫含量和有机显微组分含量等;外在条件包括地质构造、气候、水文地质、地形地貌、煤层的赋存状况、大矿和小煤窑的开采情况等.最后探讨了对不同成因的煤层自燃采取不同的预防和治理方法,为今后煤火的研究和治理奠定了理论基础. 相似文献
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Roof shale floras help understand the transition of vegetational landscapes from a peat–forming environment to a clastic one, but are seldom investigated in the Cathaysian province(typical present day China and East Asia). Here the roof shale flora of Coal Seam 6 from the lower Permian Taiyuan Formation of the Wuda Coalfield, Inner Mongolia, is systematically described and its ecostratigraphic and phytogeographic implications are discussed. The flora is composed of seven plant groups, including Lepidodendrales, Medullosales, Gigantopteridales, Peltaspermales, Noeggerathiales, Cordaitales and Cycadales. Many of these taxa are also documented in Euramerica, and the floral composition indicates a more intimate relationship between Cathaysia and Euramerica during the Cisuralian than previously thought. However, there are few genera and species in common with those of the underlying peat–forming flora. Moreover, the flora is hardly comparable with the commonly known flora of the Taiyuan Formation. Such assemblage differences are very likely due to changes of taphonomic and environmental phases, rather than evolutionary floral succession. For a full and more precise understanding of the floral composition, succession and the floristic discrepancy in different depositional environments, an ecostratigraphic investigation on the Late Palaeozoic of Cathaysia is advocated. 相似文献