| Xinjiang is rich in coal resources,one of the 13 large coal bases,but the coal field fire disaster is serious.According to statistics,about 4.5616 million tons of coal resources are lost due to coal fires every year.At the same time,the high temperature and toxic and harmful gases generated by coal fires also cause great damage to the ecological environment.It is of great significance to carry out research on coal fire control for the protection of coal resources and ecological environment.Xinjiang Daquanhu coalfield fire area is a key coal field fire area approved by the state during the 13 th Five-Year Plan period.According to the characteristics of this fire area,such as long burning history,large thickness and dip Angle of burning coal seam,many small underground connected coal kilns,and the shortcomings of traditional water injection grouting treatment technology,such as large water consumption and poor plugging effect,based on the analysis of its formation reasons and distribution characteristics of high temperature area,The comprehensive treatment technology applicable to the fire area of Daquanhu coalfield has been developed.The main research results are as follows:Based on the statistical analysis of the dip Angle of burning coal seam,the depth of burning,the thickness of recoverable coal seam and the lithology of roof and floor,it is determined that the fire area of Daquanhu coalfield belongs to the goaf fire area burning in the shallow part of steeply inclined coal seam.The fire area is a typical coal field fire caused by small coal mining,which is formed by the natural combustion of the residual coal in the goaf along the fracture and burning to the surface.The fire source in the fire area has the characteristics of concealment,wide surface and three-dimensional development of the fire area.According to the characteristics of surface combustion in the fire area,the surface of the fire area is divided into abnormal temperature area,high temperature fracture area and open fire subsidence area.The high density electrical method and transient electromagnetic method are adopted to detect the fire area of Daquanhu coalfield.The resistivity cross section is drawn and the resistivity abnormal characteristics of the detection area are analyzed.By comparing with the geological data results,the distribution range of the fire area anomaly and the goaf anomaly is obtained.The distribution ranges of three control areas,high temperature goaf,hidden high temperature area and temperature anomaly area,are determined in Daquanhu coal field.According to the distribution characteristics of the fire area in Daquanhu coalfield and the results of regional division,a comprehensive treatment technology was developed,which was mainly filled with polymer composite colloidal mud and mine solidified foam cement mud for local plugging,supplemented by step stripping drilling,water injection cooling and loess covering,and ecological restoration of the fire area.At the same time,according to the different regions of the fire area,the targeted treatment plan was formulated,and the field application was carried out in the Daquanhu coal field fire area.The application results show that the consumption of water slurry is reduced by about 23% and the economic cost is reduced by about6% compared with the conventional water injection slurry treatment.No reignition occurs after treatment,and the effective treatment of Daquanhu coalfield fire area is realized.The thesis contains 53 figures,10 tables and 62 references. |
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