Preparation, Properties and Application of Gel Materials for Coal Gangue Control

In order to solve the problem of the spontaneous combustion of coal gangue, a coal gangue fire-extinguishing material of gel–foam was developed. The foaming agent was screened by the Waring blender method with varying foam amounts, and the superabsorbent foam stabilizer was synthesized by free radical polymerization. Moreover, the gel–foam was used in a spontaneous combustion of coal gangue mountain field practice. The results showed that when the mass fraction of sodium dodecyl sulfonate and coconut oil amide propyl betaine was 0.6% and 4:6, the foaming amount was as high as 1500 mL. When the mass ratio of chitosan to acrylic acid was 1:6, the neutralization degree was 80%, the cross-linking agent was 0.8%, and the initiator was 0.01%, the water absorption of the synthesized superabsorbent foam stabilizer reached 476 mL/g. The synthesized gel–foam was tested in a spontaneous combustion coal gangue hill in a certain area, and no reburning sign was found within one month.

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Effect of Bactericides on Control of Acidification Pollution and Spontaneous Combustion of Coal Gangue Dumps in China and Its Mechanism

Sustainability ◽

10.3390/su12176697 ◽

2020 ◽

Vol 12 (17) ◽

pp. 6697

Author(s):

Zhenqi Hu ◽

Qi Zhu ◽

Jingjing Xu ◽

Xue Zhang

Keyword(s):

Reduction Potential ◽

Spontaneous Combustion ◽

Sodium Dodecyl ◽

Coal Gangue ◽

Flight Mass Spectrometry ◽

Oxidation Reduction ◽

Oxidation Reduction Potential ◽

Flocculation Test ◽

Spontaneous Combustion Of Coal ◽

Altered Cell

Oxidation of pyrite in the coal gangue dumps usually results in acidification and spontaneous combustion, causing many environmental problems such as air, soil, and water pollution. The oxidizing bacteria exacerbate problems such as acidification, spontaneous combustion, and explosions. The bacterium Acidithiobacillus ferrooxidans was first separated and isolated from coal gangue samples. Bactericides such as Triclosan, Kathon (isothiazolinones), and sodium dodecyl sulfate (SDS) were selected for our study. Our findings indicated that the addition of bactericide effectively inhibited the oxidation of Fe2+, preventing pH decreases and oxidation-reduction potential increases. We also investigated the bactericidal mechanisms employed by the three bactericides against A. ferrooxidans by conducting a protein flocculation test, scanning electron microscopy, and time-of-flight mass spectrometry. We found that the specific inhibitory activities of the three bactericides differed. Kathon treatment caused A. ferrooxidans to release small amounts of proteins and lipids. A. ferrooxidans treated with Triclosan released small amounts of lipids and large amounts of plasmas. SDS caused the bacteria to release a large amount of proteins and lipids and degraded the surface structure of the cells, resulting in altered cell morphology.

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Ambient PM2.5 and Related Health Impacts of Spontaneous Combustion of Coal and Coal Gangue

Environmental Science & Technology ◽

10.1021/acs.est.1c00150 ◽

2021 ◽

Author(s):

Wenkai Guo ◽

Bing Chen ◽

Guangyao Li ◽

Mingyue Liu ◽

Xiao Liu ◽

...

Keyword(s):

Spontaneous Combustion ◽

Coal Gangue ◽

Health Impacts ◽

Spontaneous Combustion Of Coal

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Experimental study on controlled-release inhibitor foam for restraining spontaneous combustion of coal

Energy Exploration & Exploitation ◽

10.1177/0144598720910266 ◽

2020 ◽

Vol 38 (4) ◽

pp. 1159-1177

Author(s):

Xun Zhang ◽

Jing Yang ◽

Pengfei Xie ◽

Hao Liu ◽

Qiang Deng ◽

...

Keyword(s):

Spontaneous Combustion ◽

Hollow Spheres ◽

Sodium Dodecyl ◽

Pulverized Coal ◽

Temperature Sensitive ◽

Covered Area ◽

Temperature Controlled ◽

Specific Temperature ◽

Spontaneous Combustion Of Coal ◽

Low Efficiency

A new method is proposed based on temperature-controlled self-reaction to generate and release inhibitors in the form of foam at a specific temperature, which can overcome the disadvantages of short effective time and low efficiency in the inhibition of the spontaneous combustion of coal when inhibitors are released in advance, and greatly increase the action range of inhibitor through foam diffusion. The proposed temperature-controlled foaming system was prepared with hollow spheres as solution carriers, NaHCO3 and acetic acid as basic reactants, reaction-generated CO2 as foaming gas, sodium dodecyl sulfate and sodium carboxymethyl cellulose as foaming additives, NaCl, MgCl2 and CaCl2 as additives to enhance inhibition effect, and temperature sensitive paraffin as insulating material to generate and release inhibitor foam. The effects of releasing foam on restraining the spontaneous combustion of coal were studied based on the experimental analysis of the optimum ratio of reactants and additives, hollow sphere parameters, released temperature of the foam and variation rule of CO generated by coal oxidation. The obtained results showed that the released temperature of foam was 59–61°C and the covered area of pulverized coal by inhibitor foam was 12.9–13.9 times higher than when it was directly wetted by inhibitor solution. The total effects of inhibition and inerting were achieved after pulverized coal was wetted with inhibitor foam and the efficiency of restraining the spontaneous combustion of coal reached 88.51–97.06% when temperature was increased to 160°C.

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