Determination of Critical Self-Ignition Temperature of Low-Rank Coal Using a 1 m Wire-Mesh Basket and Extrapolation to Industrial Coal Piles

2017 ◽  
Vol 31 (7) ◽  
pp. 6700-6710 ◽  
Author(s):  
Yongjun Wang ◽  
Xiaoming Zhang ◽  
Yuichi Sugai ◽  
Kyuro Sasaki
Keyword(s):  
Ignition Temperature ◽  
Wire Mesh ◽  
Low Rank ◽  
Low Rank Coal

scholarly journals Effects of temperature gradient and particle size on self-ignition temperature of low-rank coal excavated from inner Mongolia, China

2019 ◽  
Vol 6 (9) ◽  
pp. 190374 ◽  
Author(s):  
Yongjun Wang ◽  
Xiaoming Zhang ◽  
Hemeng Zhang ◽  
Kyuro Sasaki
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Temperature Gradient ◽  
Ignition Temperature ◽  
Coal Particle ◽  
Critical Value ◽  
Low Rank ◽  
Low Rank Coal ◽  
Coal Particles ◽  
Effects Of Temperature

This study investigates the effects of temperature gradient and coal particle size on the critical self-ignition temperature T CSIT of a coal pile packed with low-rank coal using the wire-mesh basket test to estimate T CSIT based on the Frank–Kamenetskii equation. The values of T CSIT , the temperature gradient and the apparent activation energy of different coal pile volumes packed with coal particles of different sizes are measured. The supercriticality or subcriticality of the coal is assessed using a non-dimensional index I HR based on the temperature gradient at the temperature cross-point between coal and ambient temperatures for coal piles with various volumes and particle sizes. The critical value I HRC at the boundary between supercriticality and subcriticality is determined as a function of pile volume. The coal status of supercritical or subcritical can be separated by critical value of I HR as a function of pile volume. Quantitative effects of coal particle size on T CSIT of coal piles are measured for constant pile volume. It can be concluded that a pile packed with smaller coal particles is more likely to undergo spontaneous combustion, while the chemical activation energy is not sensitive to coal particle size. Finally, the effect of coal particle size on T CSIT is represented by the inclusion of an extra term in the equation giving T CSIT for a coal pile.

scholarly journals Influencing factors and mechanisms involved in the ignition of low-rank coal: Implications for spontaneous combustion

2021 ◽  
Vol 228 ◽  
pp. 01015
Author(s):  
Yueling Zhang ◽  
Shengyue Ma ◽  
Jing Xiao ◽  
Yajun Tian ◽  
Kechang Xie
Keyword(s):  
Ignition Temperature ◽  
Gas Flow ◽  
Spontaneous Combustion ◽  
Rapid Assessment ◽  
Active Species ◽  
Low Rank ◽  
Low Rank Coal ◽  
Test Conditions ◽  
Ignition Mechanism ◽  
Coal Properties

Understanding the ignition mechanism of spontaneous combustion is critical for preventing it. In this work, the effects of different test conditions including oxygen concentration, heating rate, oxidation carrier gas flow rate, and sample amount on the ignition temperature were studied with a thermal gravimetric analyzer. Further, the effects of coal properties on the ignition temperature were also investigated using 15 different low-rank coals. A heterogenous ignition model was proposed that small amount of active species is the key material leading to ignition. The heterogenous ignition mechanism well explained the complex effects of test conditions and coal properties on the ignition temperature of low-rank coal. Finally, an empirical formula for predicting the ignition temperature was derived for the rapid assessment of the spontaneous combustion potential.

Determination of oxidation properties and flotation parameters of low-rank coal slimes

2019 ◽  
Vol 353 ◽  
pp. 20-26 ◽  
Author(s):  
Yuchu Cai ◽  
Meili Du ◽  
Shuili Wang ◽  
Lei Liu
Keyword(s):  
Low Rank ◽  
Low Rank Coal ◽  
Oxidation Properties

Determination of sulfur groups in pyrolysed low-rank coal by atmospheric-pressure t.p.r.

Fuel ◽  
1995 ◽  
Vol 74 (9) ◽  
pp. 1261-1266 ◽  
Author(s):  
J. Yperman ◽  
D. Franco ◽  
J. Mullens ◽  
L.C. Van Poucke ◽  
G. Gryglewicz ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Low Rank ◽  
Low Rank Coal

Determination of the optimum filter for 99mTc SPECT breast imaging using a wire mesh collimator

2017 ◽  
pp. 9-15
Author(s):  
Xianling Dong ◽  
M.I. Saripan ◽  
R. Mahmud ◽  
S. Mashohor ◽  
Aihui Wang
Keyword(s):  
Breast Imaging ◽  
Wire Mesh ◽  
Optimum Filter

INVESTIGATING A LINK BETWEEN LOW-RANK COAL BEARING CARRIZO-WILCOX AQUIFER WATER AND KIDNEY DISEASE IN EAST TEXAS

2018 ◽  
Author(s):  
Jayeeta Chakraborty ◽  
◽  
Robert B. Finkelman ◽  
William H. Orem ◽  
Matthew S. Varonka ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Low Rank ◽  
East Texas ◽  
Low Rank Coal

scholarly journals Surface Chemical Heterogeneity of Low Rank Coal Characterized by Micro-FTIR and Its Correlation with Hydrophobicity

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 239
Author(s):  
Wei Wang ◽  
Long Liang ◽  
Yaoli Peng ◽  
Maria Holuszko
Keyword(s):  
Surface Chemistry ◽  
Functional Group ◽  
Group Composition ◽  
Contact Angles ◽  
Low Rank ◽  
Surface Chemical ◽  
Carbonyl Groups ◽  
Low Rank Coal ◽  
Different Types ◽  
Aliphatic Carbon

Micro-Fourier transform infrared (micro-FTIR) spectroscopy was used to correlate the surface chemistry of low rank coal with hydrophobicity. Six square areas without mineral impurities on low rank coal surfaces were selected as testing areas. A specially-designed methodology was applied to conduct micro-FTIR measurements and contact angle tests on the same testing area. A series of semi-quantitative functional group ratios derived from micro-FTIR spectra were correlated with contact angles, and the determination coefficients of linear regression were calculated and compared in order to identify the structure of the functional group ratios. Finally, two semi-quantitative ratios composed of aliphatic carbon hydrogen, aromatic carbon hydrogen and two different types of carbonyl groups were proposed as indicators of low rank coal hydrophobicity. This work provided a rapid way to predict low rank coal hydrophobicity through its functional group composition and helped us understand the hydrophobicity heterogeneity of low rank coal from the perspective of its surface chemistry.

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