新疆煤低温氧化自燃不同阶段地质指标和煤自燃成因机理

Coal spontaneous combustion is one of the hot issues in coal research. However, the cycle of coal spontaneous combustion, self-extinguishing, then burn, and then self-extinguishing again in Xinjiang due to its seasonal changes was rarely studied. The aim of this project is to understand low temperature oxidation, storage and cooling processes of the coalbed in the case study of Xinjiang from the following aspects: the internal causes of oxidation of coal spontaneous combustion tendency; gas components produced at different stages; coupling of the external climate and geological structure. We intend to determine the scope of the center point and the combustion zone in order to establish quantitative indicators of comprehensive geological index. Geological structure of coal and oxidation characteristics, distribution, the emitted gas in early stage of smouldering combustion, the distribution and abundance of the crystalline products, such as Glauber's salt, sulfur, as well as the extent and distribution of the burnt rock are the major aspects to be investigated. The results of this study will give significant theoretical and practical basis on the determination of the coal fire range at the low-temperature oxidation stage, in order to extinguish the coal fire.

煤火问题是世界研究的热点之一。煤低温氧化自燃阶段的气体指标和基于某方面的研究而探讨其成因机制的文章很多.而对于新疆这样的因季节变化自燃煤燃烧-自灭-再燃烧-再自灭循环往复的煤火区的研究较少。本项目试图将这一类型的煤火区作为天然的煤低温氧化自燃实验室，通过内因-煤氧化自燃的倾向性，与不同阶段产生的气体组分，及其与气候、地质构造等外因的耦合研究，搞清煤层低温阶段的氧化与蓄（散）热过程，建立在关键影响因素下触发煤层自燃的成因模式。通过地质构造与氧化煤宏观煤岩类型特征、分布规律，以及煤火点燃早期焖烧散发出气体，落在地表留下芒硝、硫磺等结晶产物的分布和数量，以及烧变岩的变质程度和分布特点，可以确定中心火点和燃烧区的大致范围，由此建立一些量化的综合地质指标，这一结果对煤火低温氧化阶段煤火范围的确定有很大的帮助，进而能为灭火提供理论基础。这一研究对丰富低温氧化自燃成因理论与灭火有理论与实践意义。

煤火的发生与众多 地质因素有关。建立煤自燃地质指标对于研究煤火产生机理和采取有效的灭火措施有直接的关系。通过煤的显微组分组成、断裂构造与煤火燃烧引起的地面断裂（节理）、煤层埋藏深度、煤层厚度和煤燃烧逸出气体等指标体系等的研究，建立了煤自燃的地质指标体系。这一研究对于煤火的控制与扑灭有现实指导意义。通过上述地质指标体系的研究，从煤的结构构造、显微组分祖成和煤火的扑灭-再燃-再扑灭的过程研究，探讨煤火产生的机理。由此，提出了煤火在不同地质构造环境下的成因机理。