- Email: [email protected]
Experimental study on significant gases of coal spontaneous combustion by temperature programmed (TP)
Available online at www.sciencedirect.com
Procedia Engineering
Procedia Engineering 00 (2011)26 000–000 Procedia Engineering (2011) 120 – 125 www.elsevier.com/locate/procedia
First International Symposium on Mine Safety Science and Engineering
Experimental study on significant gases of coal spontaneous combustion by temperature programmed (TP) WU Yu-guo ∗, WU Jian-ming College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Abstract In order to provide scientific basis for the forecast of coal spontaneous combustion in the early stage, the concentration of significant gases released by the 2-2 coal samples of Shendong mine in different temperatures, i.e. CO, CO2, CH4, C2H6, C2H4 and C3H8 etc., were measured by temperature programmed oxidation(TPO). The results show CO can be regarded as the main significant gas of spontaneous combustion of 2-2 coal sample, assisted by C2H6, C3H8, C2H4, C2H2, to conclude the condition of coal spontaneous combustion . If CO is detected, showing coal has oxidized, subsequently, if C2H6, C2H4, C3H8, and C2H2 are detected in turn, showing the temperature of coal has reached 90℃, 100℃, 110℃, and above180℃ respectively.
© 2011 Published by Elsevier Ltd. Open access under CC BY-NC-ND license. Selection and/or peer-review under responsibility of China Academy of Safety Science and Technology, China University of Mining and Technology(Beijing), McGill University and University of Wollongong. Keywords: coal spontaneous combustion; programmed temperature; significant gas; early forecast
∗
Corresponding author. Email: [email protected]
1877-7058 © 2011 Published by Elsevier Ltd. Open access under CC BY-NC-ND license. doi:10.1016/j.proeng.2011.11.2148
WU Yu-guo and WUetJian-ming / Procedia Engineering 26 000–000 (2011) 120 – 125 WU Yu-guo al/ Procedia Engineering 00 (2011)
2
Introduction In the coal production, there are 5 of main natural disasters, including flood, coal spontaneous combustion, gas, outburst of coal dust, and roof collapsing, in which, the coal spontaneous combustion is especially serious. The key to coal spontaneous combustion prevention is the forecast in the early stage and the detection of fire source position, so the methods of forecasting early coal spontaneous combustion were studied broadly in the domestic and international, and the most commonly used methods are significant gases analysis, temperature measurement and tracer gas tracking etc[1-4]. At present, the method of significant gases analysis is most broadly used. By measuring a series of significant gases released in the spontaneous combustion of coal, e.g. CO, CO2, C2H6, C2H4, C3H8, and C2H2 , to reflect the degree of oxidation and combustion degree of coal. As the coal temperature rises, the kinds and volume of released significant gases change notably, so the change of kinds and volume of released significant gases can be used to forecast the coal spontaneous combustion in the early stage[5-7]. For forecasting the coal spontaneous combustion timely and accurately, the selected significant gases must meet the following requirements, • Sensitivity, once the coal is in the condition of the spontaneous combustion underground, and coal temperature exceeds a certain degree, the gases must appear. • Regularity, there are good corresponding relationship between gases concentration and coal temperatures with a high repeatability. • Testability, the gases can be detected by the common chromatogram analytical instrument . It’s difficult to experiment fully on the corresponding relationship between the kinds and concentration of released gases and coal temperatures in the coal spontaneous combustion in the site, so it is a practical method of studying the significant gases by temperature programmed in the laboratory[8-9]. 1. Experiment equipment The experiment equipments of temperature programmed include reacting furnace, coal temperaturedetecting and temperature-controlling system, gas-supplying system, and gas sample-collection system. • Reacting furnace comprises a reactor, a heating furnace and a heat preservation shell • coal temperature-detecting and temperature-controlling system. The coal temperature was detected by a thermocouple buried in the coal sample; the temperature of coal sample was controlled combined by a temperature-controlling thermocouple and a thermostat, both buried in the wall of reactor. The temperature of coal sample can be set. Taking the gas sample after the coal temperature rose to the settled temperature and had kept at this constant temperature for 5 minutes. • Gas-supplying system comprises a high-pressure air cylinder, a constant pressure valve, a flow-meter and the pipelines. • Gas sample analysis system, the gas samples were analyzed by GC-950 M made by Shanghai Haixin chromatogram instrument Co., ltd. GC-950 M can analyze CO,CO2,CH4,H2,O2,and the hydrocarbon gases of C1-C3. 3
2
5
4
8 6
9
7
1
1
1 1
1 1
121
122
Yu-guo and WU Jian-ming 120 – 125 WU Yu-guo/ WU Procedia Engineering 00 (2011)/ Procedia 000–000 Engineering 26 (2011) 3
Fig.1. The experiment equipments of temperature programmed 1-air cylinder, 2- pressure reducing valve, 3-constant pressure valve 4- steady flow valve, 5-flowmeter, 6-gas inlet pipeline, 7temprature-measruing thermocouple, 8-heating furnace, 9-reactor, 10-temperature-controlling thermocouple, 11-Gas chromatograph, 12 - power cord, 13 - external power, 14-temprature-controlling instrument
2. Condition of experiment and the process 2.1.Selection of coal sample Coal sample was from 2-2 coal seam of Shangwan mine in Shendong mining area.2-2 coal is noncaking coal. The mining method of Shangwan mine is the fully mechanized coal mining with single shaft and single workface. The coal seam is spontaneously combustible. The results of coal proximate analysis were shown in Table 1 Table 1. Test results of coal proximate analysis Coal seam No. -2
2
Mad,%
Vad,%
Aad,%
Facd,8%
Qad,kJ/kg
Had,%
9.58
33.77
3.52
53.13
31.37
5.07
Coal samples were collected from the inside of recently exposed coal seam , and the coal samples were airproofed in a plastic bag at once after completing the collection and were carried to the lab. In the lab, the airproofed plastic bag was opened, the large lumps of coal samples were smashed, the oxidation layers on the surface of coal samples were scraped off before the experimentation, and then the coal samples were crushed and screened, 50g of the particles with size of 0.088-0.098 mm was selected as the last samples for the experimentation. 2.2 The process of experiment Putting the 50g of coal samples with size of 0.088-0.098 mm into the reactor, and then connecting the gas inlet pipeline, outlet pipeline and the temperature probes (including temperature-measuring and temperature-controlling probes) with the reactor, and checking the air tightness of pipelines. After completing the preparation, the dry air was inputted into the reactor at 90ml/min, and then the coal samples were heated under the temperature programmed controlling. When the coal temperature rose to the designated degree and had kept at the constant temperature for 5 minutes, taking the gases sample and analyzing the component and concentration of released gases, and recording these data. 3. Experiment results and analysis Concentration degree of CO, CO2, CH4, C2H6, C2H4 and C3H8 released by 2-2 coal of Shangwan mine in Shendong mining area in different temperatures was detected. 3.1 Test data Table 2. Test data of significant gases released by 2-2 coal sample
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WU Yu-guo WU et Jian-ming / Procedia Engineering 26 (2011) 120 – 125 WUand Yu-guo al/ Procedia Engineering 00 (2011) 000–000
4 Temperature,℃
CO,ppm
CO2,ppm
CH4,ppm
C2H4,ppm
C2H6,ppm
C2H2,ppm
C3H8,ppm
30
2.61
426.56
4.06
0.00
0.00
0.00
0.00
40
7.25
431.07
4.20
0.00
0.00
0.00
0.00
50
17.53
476.34
4.20
0.00
0.00
0.00
0.00
60
37.97
566.48
4.18
0.00
0.00
0.00
0.00
70
75.45
729.32
4.42
0.00
0.00
0.00
0.00
80
114.77
909.92
4.84
0.00
0.00
0.00
0.00
90
183.25
1222.17
5.07
0.00
0.43
0.00
0.00
100
275.41
1618.25
5.61
0.62
0.71
0.00
0.00
110
420.78
2116.87
6.47
0.76
1.02
0.00
0.75
120
661.75
2878.30
8.33
1.53
1.60
0.00
1.05
130
1088.27
4056.02
12.28
2.48
3.12
0.00
1.49
140
1844.83
5970.27
20.03
4.95
5.17
0.00
3.04
150
3272.26
9286.84
36.38
9.39
10.52
0.00
5.65
160
6311.51
16001.79
74.75
21.57
21.14
0.00
12.58
170
10360.82
28455.27
178.82
60.62
39.12
0.00
29.69
180
16646.71
46465.21
530.36
162.56
66.04
0.00
66.58
3.2 Relation of concentration of significant gases with temperature Relation of concentration of significant gases with temperature was shown in Fig.2 600
50000 CO
CO2
500 Gas concentration,ppm
Gas concentration,ppm
40000
30000
20000
10000
CH4 C2H4 C2H6 C3H8
400 300 200 100 0
0 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Temperature,℃
30
40
50
60 70
80
90 100 110 120 130 140 150 160 170 180 Temperature,℃
Fig.2. Relation of concentration of significant gases with temperature
3.3 significant gases analysis As shown in Fig.2, CO, CO2 and CH4 were released regularly during the oxidation when the coal temperature rose from 30℃ to 180℃, and the volume of these released gases displays the exponent ℃, C 2H4 increasing as the coal temperature rose. C2 H6 appeared when the coal temperature rose to 90 appeared when coal temperature rose to 100 ℃, C 3H8 appeared when coal temperature rose to 110℃. No C2H2 was released when coal temperature rose from 30℃ to 180 ℃. CO appeared when coal temperature
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Yu-guo and WU Jian-ming 120 – 125 WU Yu-guo/ WU Procedia Engineering 00 (2011)/ Procedia 000–000 Engineering 26 (2011) 5
rose to 30℃, when the released volume of CO was little, but when coal temperature rose from 70 ℃ to 80℃, the released volume of CO increased quickly with more CO release for per unit of increase of coal temperature, which shows coal had started to oxidize rapidly, and the physical adsorption becomes weaker and weaker, but the chemical adsorption and chemical reaction take the major place. The the appearance of C2H6, C3 H8, C2 H4 shows the oxygen react vigorously with the coal. C2 H2 didn’t appear when coal temperature rose from 30℃ to 180 ℃, showing its released temperature above 180℃ , so once C2H2 appears, coal has been in the vigorous chemical reaction. So CO can be regarded as the significant gases of spontaneous combustion of 2-2 coal sample, furthermore, associated by C2 H6, C3 H8, C2H4, C2 H2, the condition of coal spontaneous combustion can be concluded, i.e., The appearance of CO shows coal had been oxidized, the appearance of C2H6 shows coal temperature has reached 90℃, the appearance of C2H4 shows coal temperature has reached 100℃, the appearance of C3 H8 shows coal temperature has reached 110℃,and the appearance of C2 H2 shows coal temperature has exceeded 180℃. 4. Conclusion • Coal spontaneous combustion is a result of coal and oxygen working together. The major reason of coal spontaneous combustion is chemical adsorption and chemical reaction of coal. • The experiment of temperature programmed oxygen shows CO can be regarded as the significant gases of spontaneous combustion of 2-2 coal sample of Shangwan mine in Shendong mining area, and, associated with C2H6, C3H8, C2H4 and C2H2, the condition of coal spontaneous combustion can be concluded, i.e., the appearance of CO shows coal had been oxidized, the appearance of C2H6 shows coal temperature has reached 90℃, the appearance of C2 H4 shows coal temperature has reached 100℃, the appearance of C3 H8 shows coal temperature has reached 110℃, and the appearance of C2H2 shows coal temperature has exceeded 180℃. • It’s an effective method to forecast the coal spontaneous combustion in early stage by the significant gases, so the method should be popularized in the coalmines with spontaneously combustible coal seams, but to the different coalmines, the significant gases should be reselected by experiment. • The significant gases were selected in the lab condition, so in the site with complex and changeable condition, the significant gases should be supplemented and revised combined with the real condition in the site. Acknowledgements Financial supports for this work provided by the key international cooperation projects (No. 2006DFA62520) and the international technologies R&D program (No. 2008DFB70100) of ministry of science and technology of China, and coal samples supports provided by Shendong coal group are gratefully acknowledged. References [1] Zhang Jianming. Underground Coal Fires in China: Origin, Detection, Fire-fighting and Prevention[M]．Beijing: China Coal Industry Publishing House, 2008． [2] Wu Jianming. Investigation And Application of New Techniques and Air-Leak Sealants for Coal Spontaneous Combustion Prevention and Extinguishment[D]. Taiyuan: Taiyuan University of Technology, 2008.
6
WU Yu-guo and WUetJian-ming / Procedia Engineering 26 000–000 (2011) 120 – 125 WU Yu-guo al/ Procedia Engineering 00 (2011)
[3] Wang Junfeng. Radon Migration in Overlying Strata during Spontaneous Combustion of Coal Underground and Its Application [D]. Taiyuan: Taiyuan University of Technology, 2010. [4] Lu Wei, Wang Deming, Zhou Fubao, eta.Study on spontaneous combustion of coal by adiabatic oxidation[J].Journal of China University of Mining & Technology, 2005, 34(2): 213-217. [5] Li Lin，Beamish B B，Jiang Deyi. Self-activation theory of spontaneous combustion of coal[J[. Journal of China Coal Society，2009，34(4): 505-508. [6] Lu P, Liao G X, Sun J H, eta .Experimental research on index gas of the coal spontaneous at low temperature stage [J]. Journal o f Loss Prevention in the Process Industries, 2004 (17): 243-247. [7] He Qilin, Dai Guanglong, Wang Deming. Critical value of CO of forecasting coal spontaneous combustion[J]. Journal of China University of Mining & Technology, 2003, 13 (2) :121- 25. [8] Deng Jun ， Yang Shu ． Determination of coal sample spontaneous combustion tendency for Shuangyashan Jixian Mine[J]．Journal of Xi’an University of Science ＆ Technology，2005，25( 4) : 411-414． [9] Xu Jingcai．Determination theory of coal spontaneous combustion zone[M]．Beijing: China Coal Industry Publishing House，2001．
125
Procedia Engineering
Procedia Engineering 00 (2011)26 000–000 Procedia Engineering (2011) 120 – 125 www.elsevier.com/locate/procedia
First International Symposium on Mine Safety Science and Engineering
Experimental study on significant gases of coal spontaneous combustion by temperature programmed (TP) WU Yu-guo ∗, WU Jian-ming College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Abstract In order to provide scientific basis for the forecast of coal spontaneous combustion in the early stage, the concentration of significant gases released by the 2-2 coal samples of Shendong mine in different temperatures, i.e. CO, CO2, CH4, C2H6, C2H4 and C3H8 etc., were measured by temperature programmed oxidation(TPO). The results show CO can be regarded as the main significant gas of spontaneous combustion of 2-2 coal sample, assisted by C2H6, C3H8, C2H4, C2H2, to conclude the condition of coal spontaneous combustion . If CO is detected, showing coal has oxidized, subsequently, if C2H6, C2H4, C3H8, and C2H2 are detected in turn, showing the temperature of coal has reached 90℃, 100℃, 110℃, and above180℃ respectively.
© 2011 Published by Elsevier Ltd. Open access under CC BY-NC-ND license. Selection and/or peer-review under responsibility of China Academy of Safety Science and Technology, China University of Mining and Technology(Beijing), McGill University and University of Wollongong. Keywords: coal spontaneous combustion; programmed temperature; significant gas; early forecast
∗
Corresponding author. Email: [email protected]
1877-7058 © 2011 Published by Elsevier Ltd. Open access under CC BY-NC-ND license. doi:10.1016/j.proeng.2011.11.2148
WU Yu-guo and WUetJian-ming / Procedia Engineering 26 000–000 (2011) 120 – 125 WU Yu-guo al/ Procedia Engineering 00 (2011)
2
Introduction In the coal production, there are 5 of main natural disasters, including flood, coal spontaneous combustion, gas, outburst of coal dust, and roof collapsing, in which, the coal spontaneous combustion is especially serious. The key to coal spontaneous combustion prevention is the forecast in the early stage and the detection of fire source position, so the methods of forecasting early coal spontaneous combustion were studied broadly in the domestic and international, and the most commonly used methods are significant gases analysis, temperature measurement and tracer gas tracking etc[1-4]. At present, the method of significant gases analysis is most broadly used. By measuring a series of significant gases released in the spontaneous combustion of coal, e.g. CO, CO2, C2H6, C2H4, C3H8, and C2H2 , to reflect the degree of oxidation and combustion degree of coal. As the coal temperature rises, the kinds and volume of released significant gases change notably, so the change of kinds and volume of released significant gases can be used to forecast the coal spontaneous combustion in the early stage[5-7]. For forecasting the coal spontaneous combustion timely and accurately, the selected significant gases must meet the following requirements, • Sensitivity, once the coal is in the condition of the spontaneous combustion underground, and coal temperature exceeds a certain degree, the gases must appear. • Regularity, there are good corresponding relationship between gases concentration and coal temperatures with a high repeatability. • Testability, the gases can be detected by the common chromatogram analytical instrument . It’s difficult to experiment fully on the corresponding relationship between the kinds and concentration of released gases and coal temperatures in the coal spontaneous combustion in the site, so it is a practical method of studying the significant gases by temperature programmed in the laboratory[8-9]. 1. Experiment equipment The experiment equipments of temperature programmed include reacting furnace, coal temperaturedetecting and temperature-controlling system, gas-supplying system, and gas sample-collection system. • Reacting furnace comprises a reactor, a heating furnace and a heat preservation shell • coal temperature-detecting and temperature-controlling system. The coal temperature was detected by a thermocouple buried in the coal sample; the temperature of coal sample was controlled combined by a temperature-controlling thermocouple and a thermostat, both buried in the wall of reactor. The temperature of coal sample can be set. Taking the gas sample after the coal temperature rose to the settled temperature and had kept at this constant temperature for 5 minutes. • Gas-supplying system comprises a high-pressure air cylinder, a constant pressure valve, a flow-meter and the pipelines. • Gas sample analysis system, the gas samples were analyzed by GC-950 M made by Shanghai Haixin chromatogram instrument Co., ltd. GC-950 M can analyze CO,CO2,CH4,H2,O2,and the hydrocarbon gases of C1-C3. 3
2
5
4
8 6
9
7
1
1
1 1
1 1
121
122
Yu-guo and WU Jian-ming 120 – 125 WU Yu-guo/ WU Procedia Engineering 00 (2011)/ Procedia 000–000 Engineering 26 (2011) 3
Fig.1. The experiment equipments of temperature programmed 1-air cylinder, 2- pressure reducing valve, 3-constant pressure valve 4- steady flow valve, 5-flowmeter, 6-gas inlet pipeline, 7temprature-measruing thermocouple, 8-heating furnace, 9-reactor, 10-temperature-controlling thermocouple, 11-Gas chromatograph, 12 - power cord, 13 - external power, 14-temprature-controlling instrument
2. Condition of experiment and the process 2.1.Selection of coal sample Coal sample was from 2-2 coal seam of Shangwan mine in Shendong mining area.2-2 coal is noncaking coal. The mining method of Shangwan mine is the fully mechanized coal mining with single shaft and single workface. The coal seam is spontaneously combustible. The results of coal proximate analysis were shown in Table 1 Table 1. Test results of coal proximate analysis Coal seam No. -2
2
Mad,%
Vad,%
Aad,%
Facd,8%
Qad,kJ/kg
Had,%
9.58
33.77
3.52
53.13
31.37
5.07
Coal samples were collected from the inside of recently exposed coal seam , and the coal samples were airproofed in a plastic bag at once after completing the collection and were carried to the lab. In the lab, the airproofed plastic bag was opened, the large lumps of coal samples were smashed, the oxidation layers on the surface of coal samples were scraped off before the experimentation, and then the coal samples were crushed and screened, 50g of the particles with size of 0.088-0.098 mm was selected as the last samples for the experimentation. 2.2 The process of experiment Putting the 50g of coal samples with size of 0.088-0.098 mm into the reactor, and then connecting the gas inlet pipeline, outlet pipeline and the temperature probes (including temperature-measuring and temperature-controlling probes) with the reactor, and checking the air tightness of pipelines. After completing the preparation, the dry air was inputted into the reactor at 90ml/min, and then the coal samples were heated under the temperature programmed controlling. When the coal temperature rose to the designated degree and had kept at the constant temperature for 5 minutes, taking the gases sample and analyzing the component and concentration of released gases, and recording these data. 3. Experiment results and analysis Concentration degree of CO, CO2, CH4, C2H6, C2H4 and C3H8 released by 2-2 coal of Shangwan mine in Shendong mining area in different temperatures was detected. 3.1 Test data Table 2. Test data of significant gases released by 2-2 coal sample
123
WU Yu-guo WU et Jian-ming / Procedia Engineering 26 (2011) 120 – 125 WUand Yu-guo al/ Procedia Engineering 00 (2011) 000–000
4 Temperature,℃
CO,ppm
CO2,ppm
CH4,ppm
C2H4,ppm
C2H6,ppm
C2H2,ppm
C3H8,ppm
30
2.61
426.56
4.06
0.00
0.00
0.00
0.00
40
7.25
431.07
4.20
0.00
0.00
0.00
0.00
50
17.53
476.34
4.20
0.00
0.00
0.00
0.00
60
37.97
566.48
4.18
0.00
0.00
0.00
0.00
70
75.45
729.32
4.42
0.00
0.00
0.00
0.00
80
114.77
909.92
4.84
0.00
0.00
0.00
0.00
90
183.25
1222.17
5.07
0.00
0.43
0.00
0.00
100
275.41
1618.25
5.61
0.62
0.71
0.00
0.00
110
420.78
2116.87
6.47
0.76
1.02
0.00
0.75
120
661.75
2878.30
8.33
1.53
1.60
0.00
1.05
130
1088.27
4056.02
12.28
2.48
3.12
0.00
1.49
140
1844.83
5970.27
20.03
4.95
5.17
0.00
3.04
150
3272.26
9286.84
36.38
9.39
10.52
0.00
5.65
160
6311.51
16001.79
74.75
21.57
21.14
0.00
12.58
170
10360.82
28455.27
178.82
60.62
39.12
0.00
29.69
180
16646.71
46465.21
530.36
162.56
66.04
0.00
66.58
3.2 Relation of concentration of significant gases with temperature Relation of concentration of significant gases with temperature was shown in Fig.2 600
50000 CO
CO2
500 Gas concentration,ppm
Gas concentration,ppm
40000
30000
20000
10000
CH4 C2H4 C2H6 C3H8
400 300 200 100 0
0 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Temperature,℃
30
40
50
60 70
80
90 100 110 120 130 140 150 160 170 180 Temperature,℃
Fig.2. Relation of concentration of significant gases with temperature
3.3 significant gases analysis As shown in Fig.2, CO, CO2 and CH4 were released regularly during the oxidation when the coal temperature rose from 30℃ to 180℃, and the volume of these released gases displays the exponent ℃, C 2H4 increasing as the coal temperature rose. C2 H6 appeared when the coal temperature rose to 90 appeared when coal temperature rose to 100 ℃, C 3H8 appeared when coal temperature rose to 110℃. No C2H2 was released when coal temperature rose from 30℃ to 180 ℃. CO appeared when coal temperature
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Yu-guo and WU Jian-ming 120 – 125 WU Yu-guo/ WU Procedia Engineering 00 (2011)/ Procedia 000–000 Engineering 26 (2011) 5
rose to 30℃, when the released volume of CO was little, but when coal temperature rose from 70 ℃ to 80℃, the released volume of CO increased quickly with more CO release for per unit of increase of coal temperature, which shows coal had started to oxidize rapidly, and the physical adsorption becomes weaker and weaker, but the chemical adsorption and chemical reaction take the major place. The the appearance of C2H6, C3 H8, C2 H4 shows the oxygen react vigorously with the coal. C2 H2 didn’t appear when coal temperature rose from 30℃ to 180 ℃, showing its released temperature above 180℃ , so once C2H2 appears, coal has been in the vigorous chemical reaction. So CO can be regarded as the significant gases of spontaneous combustion of 2-2 coal sample, furthermore, associated by C2 H6, C3 H8, C2H4, C2 H2, the condition of coal spontaneous combustion can be concluded, i.e., The appearance of CO shows coal had been oxidized, the appearance of C2H6 shows coal temperature has reached 90℃, the appearance of C2H4 shows coal temperature has reached 100℃, the appearance of C3 H8 shows coal temperature has reached 110℃,and the appearance of C2 H2 shows coal temperature has exceeded 180℃. 4. Conclusion • Coal spontaneous combustion is a result of coal and oxygen working together. The major reason of coal spontaneous combustion is chemical adsorption and chemical reaction of coal. • The experiment of temperature programmed oxygen shows CO can be regarded as the significant gases of spontaneous combustion of 2-2 coal sample of Shangwan mine in Shendong mining area, and, associated with C2H6, C3H8, C2H4 and C2H2, the condition of coal spontaneous combustion can be concluded, i.e., the appearance of CO shows coal had been oxidized, the appearance of C2H6 shows coal temperature has reached 90℃, the appearance of C2 H4 shows coal temperature has reached 100℃, the appearance of C3 H8 shows coal temperature has reached 110℃, and the appearance of C2H2 shows coal temperature has exceeded 180℃. • It’s an effective method to forecast the coal spontaneous combustion in early stage by the significant gases, so the method should be popularized in the coalmines with spontaneously combustible coal seams, but to the different coalmines, the significant gases should be reselected by experiment. • The significant gases were selected in the lab condition, so in the site with complex and changeable condition, the significant gases should be supplemented and revised combined with the real condition in the site. Acknowledgements Financial supports for this work provided by the key international cooperation projects (No. 2006DFA62520) and the international technologies R&D program (No. 2008DFB70100) of ministry of science and technology of China, and coal samples supports provided by Shendong coal group are gratefully acknowledged. References [1] Zhang Jianming. Underground Coal Fires in China: Origin, Detection, Fire-fighting and Prevention[M]．Beijing: China Coal Industry Publishing House, 2008． [2] Wu Jianming. Investigation And Application of New Techniques and Air-Leak Sealants for Coal Spontaneous Combustion Prevention and Extinguishment[D]. Taiyuan: Taiyuan University of Technology, 2008.
6
WU Yu-guo and WUetJian-ming / Procedia Engineering 26 000–000 (2011) 120 – 125 WU Yu-guo al/ Procedia Engineering 00 (2011)
[3] Wang Junfeng. Radon Migration in Overlying Strata during Spontaneous Combustion of Coal Underground and Its Application [D]. Taiyuan: Taiyuan University of Technology, 2010. [4] Lu Wei, Wang Deming, Zhou Fubao, eta.Study on spontaneous combustion of coal by adiabatic oxidation[J].Journal of China University of Mining & Technology, 2005, 34(2): 213-217. [5] Li Lin，Beamish B B，Jiang Deyi. Self-activation theory of spontaneous combustion of coal[J[. Journal of China Coal Society，2009，34(4): 505-508. [6] Lu P, Liao G X, Sun J H, eta .Experimental research on index gas of the coal spontaneous at low temperature stage [J]. Journal o f Loss Prevention in the Process Industries, 2004 (17): 243-247. [7] He Qilin, Dai Guanglong, Wang Deming. Critical value of CO of forecasting coal spontaneous combustion[J]. Journal of China University of Mining & Technology, 2003, 13 (2) :121- 25. [8] Deng Jun ， Yang Shu ． Determination of coal sample spontaneous combustion tendency for Shuangyashan Jixian Mine[J]．Journal of Xi’an University of Science ＆ Technology，2005，25( 4) : 411-414． [9] Xu Jingcai．Determination theory of coal spontaneous combustion zone[M]．Beijing: China Coal Industry Publishing House，2001．
125