Study on infrared detection of coal seam spontaneous combustion high temperature anomaly area

2021 ◽  
Author(s):  
Linchao Shi ◽  
Xiangyang Zhang ◽  
Biao Kong ◽  
Angling Ren ◽  
Linxuan Li ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Shen ◽  
Qiang Zeng

AbstractIn the present paper, with using diverse methods (including the SEM, the XRD, the TPO, the FTIR, and the TGA) , the authors analysed samples of the major coal seam in Dahuangshan Mining area with different particle sizes and with different heated temperatures (from 50 to 800 °C at regular intervals of 50 °C). The results from SEM and XRD showed that high temperature and high number of pores, fissures, and hierarchical structures in the coal samples could facilitate oxidation reactions and spontaneous combustion. A higher degree of graphitization and much greater number of aromatic microcrystalline structures facilitated spontaneous combustion. The results from TPO showed that the oxygen consumption rate of the coal samples increased exponentially with increasing temperature. The generation rates of different gases indicated that temperatures of 90 °C or 130 °C could accelerate coal oxidation. With increasing temperature, the coal oxidation rate increased, and the release of gaseous products was accelerated. The FTIR results showed that the amount of hydroxide radicals and oxygen-containing functional groups increased with the decline in particle size, indicating that a smaller particle size may facilitate the oxidation reaction and spontaneous combustion of coal. The absorbance and the functional group areas at different particle sizes were consistent with those of the heated coal samples, which decreased as the temperature rose. The results from TGA showed that the characteristic temperature T3 declined with decreasing particle size. After the sample with 0.15–0.18 mm particle size was heated, its carbon content decreased, and its mineral content increased, inhibiting coal oxidation. This result also shows that the activation energy of the heated samples tended to increase at the stage of high-temperature combustion with increasing heating temperature.


2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Dariusz OBRACAJ ◽  
Marek KORZEC ◽  
Tien Tung VU

The liability of coal to spontaneous combustion is the principal cause of mine fires. Spontaneouscombustion is one of the main threats in Polish and Vietnamese coal mines. The article presents an analysisof the spontaneous combustion of coal in mines of both countries. It is related to the natural prone of coalto spontaneous heating and consequently to its self-ignition. Despite the relevant recognition of themethods of preventing this threat, in mines, spontaneous combustion occurs during the exploitation ofcoal seams with low and very high self-ignition tendency. Apart from the technical factors related to thedesign of coal seam mining, the properties of coal have a significant impact on the occurrence ofspontaneous combustion. Their correct recognition is essential to the precautions against spontaneouscombustion for minimalizing the risk of a mine fire. Therefore, it is necessary to study the factorsinfluencing the propensity of coal to spontaneous heating. A review of the methods used to determine thepropensity of coal to spontaneous combustion is presented in the article. Based on the high-temperaturemethod of determining the propensity of coals to spontaneous combustion, the influence of selectedfactors related to samples' preparation for testing on the determination result was investigated. Theinfluence of the fractional decomposition and the moisture content in the prepared samples on thedetermination result was demonstrated. The presented research results may improve research proceduresfor determining the propensity of coal to spontaneous combustion.


2013 ◽  
Vol 634-638 ◽  
pp. 3688-3695 ◽  
Author(s):  
Yang Xiao ◽  
Shu Gang Li ◽  
Jun Deng ◽  
Xu Wang

In China, as popularizing the technology of fully mechanized top-coal mining and increasing the strength and depth of mining, the gutter-up gob can be formed. But the work of fire preventing and extinguishing for its coal spontaneous combustion is more complexity and difficulty. In this paper, based on geology parameters and mining practice for 93up12 fully mechanized top-coal caving face in Nantun coalmine, the form and character of gutter-up gob are analyzed. According to the hidden danger of high temperature for spontaneous combustion in the gob, we adopt the comprehension technologies of fire extinguishing and preventing which include sealing air-leakage, grouting, and injecting compound gel with fly-ash, foam of retarding oxidation, liquid carbon dioxide, and gas of nitrogen. By putting in practice the pre-controlling technology in gutter-up gob and monitoring data of target gases, it obtains a good effect and ensures the safety in production of the fully-mechanized top-coal caving face.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Youxin Zhao ◽  
Qingjie Qi ◽  
Xinlei Jia

To accurately and reliably predict the time of spontaneous combustion of fractured coal around a borehole induced by gas drainage along the seam, this study performed an orthogonal test taking the No. 10 Coal Mine of Pingdingshan as the research object, in terms of the suction negative pressure and coal seam buried depth. COMSOL Multiphysics was used to model the orthogonal test results, and a multielement statistical analysis of four factors and their relationships with the spontaneous combustion of coal around the borehole and a single-factor analysis in line with the site conditions were performed on the modeling results through multiple regression. The results showed a nonlinear regression relationship between the sealing hole length, sealing hole depth, negative pressure, and coal seam depth and the spontaneous combustion of the coal around the gas drainage borehole; the prediction regression model is significant. Taking the field gas drainage in the No. 10 Coal Mine of Pingdingshan as an example, the relationship between the time of spontaneous combustion of gas drainage and the drainage pressure follows a power of two. When the drainage negative pressure is less than 45 kPa, the coal around the borehole is more likely to undergo spontaneous combustion with increasing pressure, and the sealing hole length has a positive linear correlation with the time of spontaneous combustion of the coal around the borehole. When the sealing hole length is 23 m, the time of spontaneous combustion of the coal around the gas drainage hole is >500 days, and the coal around the borehole does not easily undergo spontaneous combustion. When the sealing depth is 15 m, the time of spontaneous combustion of the coal around the gas drainage hole is 76 days, which is most likely to cause spontaneous combustion.


2014 ◽  
Vol 881-883 ◽  
pp. 1638-1641
Author(s):  
Xian Long Sun ◽  
Er Xin Gao ◽  
Hong Fen Zhang ◽  
Qiang Wang ◽  
Li Juan Li

Based on the geological and the experimental data of the13#coal seam of Sun-Cun Coal Mine, the relationship curve between the geothermal heat in Sun-Cun coal mine and experimental wind speed has been fit out.According this and the laboratory experiments,the relational expression between the quantity of CO2 produced in the period of spontaneous combustion and the wind speed in the coal mine has been developed. The research results show that when the wind speed exceeds 2m/s,the quantity of CO2 produced has a sharp rising tendency.


2013 ◽  
Vol 718-720 ◽  
pp. 1639-1644 ◽  
Author(s):  
Yu Bing Mu

The 3-105 half isolated island fully mechanized caving face in Tengdong coal mine which in complex geological and high temperature condition, has a spontaneous combustion feature that is different from normal advancing mechanized caving face, such as slowly advance speed, stress concentration and air leakage of inside-impending gob. To overcome the dangerous possibility of spontaneous combustion between the roof coal seam inside-impending gobs, small coal pillar and adjacent gob of half isolated island fully mechanized caving face, analysis spatial structure of overlying strata roof and spontaneous combustion characteristics. Based on the result of pressure can be measured and tracer gas test of air leakage channels, determine the potential air leakage areas. The MEA plugging wind material is pumped into roadway and SPA-4 plugging wind material is spray around known air leakage or high temperature area to eliminate the hazards of spontaneous combustion of the potential danger zone, and protects the safe mining of the working face.


1979 ◽  
Vol 16 (9) ◽  
pp. 1882-1887 ◽  
Author(s):  
B. N. Church ◽  
A. Matheson ◽  
Z. D. Hora

An area of several square kilometres of subbituminous coal at Hat Creek has been burnt in prehistoric times, probably as a result of spontaneous combustion. The product of this combustion is a yellow and reddish partly fused rock with high temperature minerals and chemical composition unlike volcanic rocks. The effect of thermal metamorphism within a few hundred feet of the burnt zone is an apparent slight increase in coalification levels above regional metamorphic grades.


Sign in / Sign up

Export Citation Format

Share Document