Research On Detection And Treatment Technology Of Abandoned Small Coal Kiln Fire Area In Dongfeng Mine

China is a large coal mining and consumption country,and is also the most serious country in the world by coal mine spontaneous combustion fire,especially in Inner Mongolia,Xinjiang,Ningxia and Shanxi.According to statistics,spontaneous combustion of coal in small coal kilns caused by private mining of abandoned small coal kilns and ancient kilns accounted for more than 95%of coal spontaneous combustion fires.The detection and treatment of spontaneous combustion sources in abandoned small coal kilns has become an important research direction,which is related to whether the entire mine can be safely produced.Based on the actual situation of the abandoned small coal kiln in the upper part of of Dongfeng Mine,this thesis adopts a research method combining theoretical analysis,on-site testing and on-site engineering practice,and proposes a ground " Isotopic radon detection-magnetoelectric anomaly" combined technology to detect the concealment of small coal kilns fire source technology.Then,the use of KMH-2 high-solid water colloidal fire-fighting materials to control the fire area has important reference significance for solving the threat of abandoned coal kilns in the coal mine area to the mining of coal seams.Based on the theoretical basis of coal spontaneous combustion mechanism and factors afecting coal spontaneous combustion,combined with the actuall situation of the small coal kiln fire area in the second mining area of Dongfeng Mine,the characteristics of coal spontaneous combustion in small coal kiln are as follows:the fire source is mostly distributed in a wide range of local fire source,the location of fire source is hidden and difficult to detect accurately,and the fire source is in a threedimensional state.In view of the spontaneous combustion characteristics of small coal kilns in the upper part of Dongfeng Mine,it is difficult for a single detection technology to accurately detect the location and range of the fire source.After comparing and analyzing various geophysical methods,the combined technology of "Isotopic radon detection-magnetoelectric anomaly" on the ground is proposed to detect hidden fire sources in mines.According to the preliminary exploration results,combined with the distribution of underground roadways,the fire source location was further detected and verified through the downhole limited temperature measurement borehole.Using the electric and magnetic signal abnormalities in the fire source area and the principle of radon concentration abnormality,a large area of suspicious fire area of spontaneous combustion coal seam was investigated.The area of the fire area was about 800 m2,and the area of the fire area delineated by the downhole temperature measurement borehole was about 450 m2.The fire source is located within the bounds of the combined technology of " Isotopic radon detection-magnetoelectric anomaly",which illustrates the effectiveness of the ground" Isotopic radon detection-magnetoelectric anomaly" combined technology to detect fire sources in small coal kilns.Based on the detection results of the fire zone,the downhole grouting borehole was designed and implemented,and the fire zone management work was completed.After a total of 28,500 m3 of colloidal materials were poured,the temperature and gas concentration changes in the fire area met the requirements of Article 279 of the "Coal Mine Safety Regulations",and the management of the small coal kiln fire area in the second mining area of Dongfeng Mine was successfully completed.After the fire area was treated,the safe use of the track and transportation lanes in the second mining area was ensured,and the coal resources of about 6.53 Mt affected by the fire area were liberated.Figure[47]Table[13]Reference[88]...