Coal and gas outburst is a very complicated dynamic phenomenon of coal rock which contains gas, it can be regarded as a catastrophe behavior of a complicated non-linear dynamic system during its evolving process in space and time, and also be one of the major disasters influencing safe production of coal mine.
Electromagnetic waves propagating characteristic in the process of coal rock outburst is analyzed in theory,which can obtain the power spectrum distribution of electromagnetic emission signal,as well as the relationship with the distance of radiation source.
On the basis of fractal theory,the fractal dimension models of surface,volume and block are put out. Fractal dimension of surface density is researched by mea-suring the coal outcrop section of Wuhu Mountain. Furthermore,coal rock is strdied by the pore structre testing.
When the transient Reyleigh wave prospecting was applied in mining, taking advantage of the frequency dispersion character of Reyleigh wave and the correlation between transmission velocity of Reyleigh wave and physical mechanics property of coal rock, a new predicting technique of coal and gas outburst was developed.
The article describes the theory and technology on gas extraction to relief underground pressure in high gassy Huainan mining area, on control of surrounding rocks in loose and soft coal-rock roadway and also the ideal and technology for underground mine design in high gassy complicated geological condition, it introduces the main results achieved in safety and high effective extraction and comprehensive utilization in Huainan Mine Group and economic and social benefits obtained.
The Taiyuan Formation is composed of limestones, aluminous mudstones, siltstones, silty mudstones, sandstones, and mineable coal seams, with a total thickness varying from 44.9 m to 193.48 m.
Coal mine operations generally occur in stratified layers where avoiding cutting into rock layers beyond the coal-rock surface is important.
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They may also possibly contain some fragments of non-coal rock derived from contamination of the mined product by roof or floor strata.
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The gas outburst of Wangying shaft is enhanced with the depth increase,and it has selectivity to the zone and seam. As usual, most of the gas bursts out in free static storage state, at the same time,the coal bursts out too. Drilling and setting out gas under the shaft is a usef,safety and economic method.
A mathematical model to simulate crack′s fracturing and propagating in low permeable coal and rock mass due to hydraulic facture in conjunction with solidliquid coupled interaction have been set up and puts forward its numerical solution. By the example of water injection into low permeable No3 coal seam of Wangzhuang Mine, Luan Mining Bureau,the calculation results indicate that in the process of hydraulic fracture the crack′s width does not increase infinitely with the increase of water pressure and the...
By research on the macrocoal rock,microcoal rock,its reflectance and pores characteristics,the paper analyses the features of enrichment of coal bed gas in Hancheng coal area.It has directing significance for extraction and utilization of coal bed gas.