The impact of surface air leakage on coal spontaneous combustion hazardous zone in gob of shallow coal seams: A case study of Bulianta Mine, China

Fuel ◽  
2021 ◽  
Vol 295 ◽  
pp. 120636
Author(s):  
Hui Zhuo ◽  
Botao Qin ◽  
Qinghe Qin
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.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Xiaowei Zhai ◽  
Bo Wang ◽  
Shangrong Jiang ◽  
Weixia Zhang

In order to prevent and control coal spontaneous combustion effectively in the gob of U+L working face, the 30105 working face of Hanglaiwan mine was taken as the research object. The relationship models between oxygen concentration and burial depth of the two tunnels in the gob of U+L working face were established. The distribution of oxygen in the gob of the working face of U+L ventilation system was studied by field observation combined with numerical simulation. The results show that the air leakage in the gob is serious. There are a number of fluctuation areas where the oxygen concentration first decreases and then increases in the air intake side of the gob. The oxygen concentration peaked at 100m, 175m, and 245m, respectively, from the intake side of the gob. In the same position of the gob depth, the air leakage intensity on the intake side is generally higher than that on the return side, and the oxygen concentration on the intake side of the gob is slower than the return side. Oxygen concentration maintains at 5.09% when the depth of gob reaches 400m. Measures to prevent coal spontaneous combustion should be strengthened in the air intake side.


Fuel ◽  
2021 ◽  
Vol 289 ◽  
pp. 119852
Author(s):  
Hongwei Liu ◽  
Fei Wang ◽  
Ting Ren ◽  
Ming Qiao ◽  
Jingjing Yan

2021 ◽  
Vol 250 ◽  
pp. 534-541
Author(s):  
Vladimir Zubov ◽  
Dmitrii Golubev

Spontaneous combustion of coal remains an important problem for coal mines, which can lead to an explosion of methane and coal dust. Accidents associated with spontaneous combustion of coal can cause significant economic losses to coal mining companies, as well as entail social damage – injuries and loss of life. Accidents are known at the Kuzbass mines, which occurred as a result of negligent attitude to the danger of spontaneous combustion of coal, the victims of which were dozens of people. The analysis of emergency situations associated with spontaneous combustion of coal shows that the existing wide range of means of preventing endogenous fires does not provide complete safety when working out coal seams prone to spontaneous combustion, therefore, spontaneous combustion places continue to occur in mines. The consequences that may arise as a result of a methane explosion initiated by a self-ignition place indicate the need to improve the used technologies. The purpose of the work is to determine the impact of modern technological solutions used in functioning mines during underground mining of flat-lying coal seams prone to spontaneous combustion, and to develop new solutions that reduce endogenous fire hazard. Conclusions on the influence of leaving coal pillars in the developed space, isolated air removal from the stoping face through the developed space, the length of the stoping face and the excavation pillar, and other factors on the danger of the formation of spontaneous combustion places are presented. Conclusions about the possibility of using modern technological solutions in future are also drawn.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4891
Author(s):  
Magdalena Tutak ◽  
Jarosław Brodny ◽  
Dawid Szurgacz ◽  
Leszek Sobik ◽  
Sergey Zhironkin

Various types of natural hazards are inextricably linked to the process of underground hard coal mining. Ventilation hazards—methane and spontaneous combustion of coal—are the most dangerous; they pose a major threat to the safety of the workers and decrease the effectiveness of the whole coal production process. One of the methods designed to limit the consequences of such hazards is based on the selection of a ventilation system that will be suitable for the given mining area. The article presents a case study of an active longwall area, where—due to increasing ventilation hazard (methane and spontaneous combusting of coal)—the whole system was rebuilt. The U-type ventilation system was used in the initial stage of the extraction process, however, it often generated methane in amounts that exceeded the allowable values. Consequently, such conditions forced the change of the ventilation system from a U–type to Y–type system. The new system was installed during the ongoing mining process, unlike the usual practice. The article presents the results of tests on mine gas concentrations and descriptive statistics for both types of ventilation system. The results clearly demonstrate that the U-type longwall ventilation system, in the case of high methane release hazard, prevents safe and effective operation. At the same time, the use of this system limits the carbon oxidation reactions in the goaf, leading to spontaneous heating and combustion, which is confirmed by the low concentrations of gases—by-products of these reactions. In turn, the use of the Y-type longwall ventilation system ensures safe and effective operation in areas with high methane release hazard, but at the same time deteriorates the safety associated with the spontaneous combusting of coal. The presented case—both from a scientific and practical perspective—is quite interesting and greatly broadens the knowledge in the scope of an efficient ventilation system for underground workings.


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