Datong Coal Mine Group Company

Datong, China

Datong Coal Mine Group Company

Datong, China
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Lu C.-P.,State Key Laboratory of Coal Resources and Mine Safety | Dou L.-M.,State Key Laboratory of Coal Resources and Mine Safety | Wang Y.-F.,Datong Coal Mine Group Corporation
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2010

By TDS-6 microseism (MS) test system, the MS effect of the compound coal-rock samples from Xinzhouyao Coal Mine was studied in the process of deformation, fracture and rockburst failure, especially the evolvement of MS frequency-spectrum before and after rockburst failure was revealed. Using SOS MS monitoring system, the MS activity patterns of working face 8929 of Xinzhouyao Coal Mine were measured. The achieved results are as follows. (1) The rockburst precursory signal shows low-frequency character, the shorter the interval time between precursory and mainshock signal is, the lower the main frequency is. The spectrum of mainshock signal is wider, but the low-frequency component (0-50 Hz) will increase obviously. The aftershock signal shows high-frequency feature. (2)The correlation between the events, the total energy and the main frequency of MS signals is negative. Especially when the pressure and rockbursts were induced by roof fracture, the main frequency of MS signals is lowest. (3) The main frequency of rockburst precursory signals is about 0-50 Hz by measurement in field, and amplitude is lower. The spectrum of rockburst signals is wider, and the low-frequency component (0-20 Hz) will obviously increase, simultaneously the amplitude reaches to maximum. After rockburst, MS signals show the high-frequency and low-amplitude feature, and main frequency is about 0-200 Hz.


Yu B.,Datong Coal Mine Group Company
Journal of Rock Mechanics and Geotechnical Engineering | Year: 2016

Accidents such as support failure and excessive deformation of roadways due to drastic changes in strata behaviors are frequently reported when mining the extra-thick coal seams Nos. 3-5 in Datong coal mine with top-coal caving method, which significantly hampers the mine's normal production. To understand the mechanism of strata failure, this paper presented a structure evolution model with respect to strata behaviors. Then the behaviors of strata overlying the extra-thick coal seams were studied with the combined method of theoretical analysis, physical simulation, and field measurement. The results show that the key strata, which are usually thick-hard strata, play an important role in overlying movement and may influence the mining-induced strata behaviors in the working face using top-coal caving method. The structural model of far-field key strata presents a "masonry beam" type structure when "horizontal O-X" breakage type happens. The rotational motion of the block imposed radial compressive stress on the surrounding rock mass of the roadway. This can induce excessive deformation of roadway near the goaf. Besides, this paper proposed a pre-control technology for the hard roof based on fracture holes and underground roof pre-splitting. It could effectively reduce stress concentration and release the accumulated energy of the strata, when mining underground coal resources with top-coal caving method. © 2016 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences.


Yao X.,China University of Mining and Technology | Liu J.,China University of Mining and Technology | Gong G.,China University of Mining and Technology | Gong G.,Beijing Institute of Labor Protection Science | And 3 more authors.
International Journal of Mining Science and Technology | Year: 2013

A series of activated carbons from Taixi anthracite were prepared by steam activation in the presence of KOH and then they were modified by different methods. The regulation of porosity and the modification of surface chemistry were carried out with the aim to improve the benzene adsorption capacity of activated carbon. The influences of KOH and activation process parameters including activation temperature, activation time and steam flow rate on porosity of activated carbon were evaluated, and the effect of modification methods on surface chemistry was investigated. Also, the relationship between benzene adsorption capacity and porosity and surface chemistry was analyzed. Results show that activation temperature is the dominant factor in the activation process; the introduction of KOH into the raw material can enhance the reactivity of char in activation process, meanwhile it shows a negative effect on the porosity development, especially on the mesopore development. Results of FTIR analysis indicate that anthracite-based activated carbon with condensed aromatics and chemically inert oxygen does not present the nature to be surface modified. Besides, benzene adsorption capacity has an approximate linear relationship with surface area and in our preparation, benzene adsorption capacity and surface area of activated carbon are up to 1210 m2/g and 423 mg/g, respectively. © 2013 Published by Elsevier B.V. on behalf of China University of Mining & Technology.


Liu C.-Y.,China University of Mining and Technology | Yang J.-X.,China University of Mining and Technology | Yu B.,China University of Mining and Technology | Yu B.,Datong Coal Mine Group Company | Yang P.-J.,China University of Mining and Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2014

In order to understand the coal face pressure effects from the hard roof group structure breaking and instability, the relation was proved between the hard roof group structure and strata behavior. It investigated the instability characteristics of roof group structure combining the research methods of the theoretical analysis, similar simulation experiment and field measured according to the conditions of hard thick roof group structure under multi gob in Datong coal mining area. It shows that: the roof group structure instability has some certain probability characteristic; multiple parameters Weibull function describes well on instability forms in breaking roof group structure, and establishes the similar roof structure instability rate under the condition of the close distance coal seam group, then gives the roof instability parameters, and analyzes on the goaf roof instability rate in Jurassic coal seam group. It is shown that the roof group structure instability rate have some influence on the face support resistance. Through the mine pressure and support resistance measurement results on the end and central position of the coal face, verify the hard thick roof instability regularity in the No. 15 face of Yongding Village Coal Mine in Datong mining area.


Yu B.,China University of Mining and Technology | Yu B.,Datong Coal Mine Group Company | Liu C.-Y.,China University of Mining and Technology | Yang J.-X.,China University of Mining and Technology | Liu J.-R.,Datong Coal Mine Group Company
Meitan Xuebao/Journal of the China Coal Society | Year: 2014

In Datong mining area, carboniferous coal seam of 8105 working face under the Jurassic coal gob pillar leaving was characterized by strong pressure, with the theoretical analysis and field testing applied, the Jurassic coal mined-out area of coal pillar stress influence law and carboniferous coal seam roof collapse of crack zone was analyzed, and obtained a dual-line coal seam mining face under strong influence column of the strata "coal pillar-overburden movement" joint mechanism. It shows that the Jurassic coal gob pillar leaving in the horizontal and vertical stress is higher, up to 10.5-13.5 MPa, and stress concentration zone depth of 40-70 m, the shear stress spread range up 180 m; The roof of 8105 working face collapse crack zone height range is 150-170 m; face appeared a strong pressure of coal pillar is made up of the coal pillar and coal seam roof collapse result of combined effects of crack movement.


Yu B.,Datong Coal Mine Group Company | Zhang Z.,Chongqing University | Kuang T.,Datong Coal Mine Group Company | Liu J.,Datong Coal Mine Group Company
Rock Mechanics and Rock Engineering | Year: 2016

Coal pillar stability is strongly influenced by the site-specific geological and geotechnical conditions. Many geological structures such as faults, joints, or rock intrusions can be detrimental to mining operations. In order to evaluate the performance of coal pillars under weak roof degraded by igneous rock intrusion, stress and deformation monitoring was conducted in the affected tailgate areas of Nos. 8208 and 8210 longwalls in Tashan coal mine, Shanxi Province, China. The measurements in the 8208 longwall tailgate showed that the mining-induced stresses in 38-m-wide coal chain pillars under the overburden depth of 300–500 m started to increase at about 100 m ahead of the 8208 longwall working face and reached its peak level at approximately 50 m ahead of the longwall face. The peak stress of 9.16 MPa occurred at the depth of 8–9 m into the pillar from the tailgate side wall. In comparison, disturbance of the headgate block pillar area was negligible, indicating the difference of abutment pressure distribution between the tailgate and headgate sites where the adjacent unmined longwall block carried most of the overburden load. However, when the longwall face passed the headgate monitoring site by 360–379 m, the pillar stress increased to a peak value of 21.4 MPa at the pillar depth of 13 m from the gob side mainly due to stress redistribution in the chain pillar. In contrast to the headgate, at the tailgate side, the adjacent goaf was the dominant triggering factor for high stress concentrations in the chain pillar. Convergence measurements in the tailgate during longwall mining further indicated the evolution characteristics of coal pillar deformation, clearly showing that the gateroad deformation is mainly induced by the longwall extraction it serves. When predicting the future pillar loads from the monitored data, two stress peaks appeared across the 38-m-wide tailgate coal pillar, which are separated by the lower stress area within the pillar center. This 10-m-wide elastic pillar core area indicates that the coal pillar may be narrowed to 30 m to improve coal recovery. The measurements further indicate that, if the headgate of the next panel can be developed after the adjacent gob becomes stable, the coal pillar width may be further reduced to 20 m. This study is applicable for the chain pillar design, the gateroad secondary support design ahead of the longwall mining face, and the gateroad preparation of the next longwall panel under similar geological and geotechnical conditions. © 2016 Springer-Verlag Wien


Liu J.-R.,Datong Coal Mine Group Ltd Company | Kang Q.-T.,North China Institute of Science and Technology
Caikuang yu Anquan Gongcheng Xuebao/Journal of Mining and Safety Engineering | Year: 2013

Affected by complicated factors such as large section, low strength of coal mass, high in-situ stress, rich water roof and Mudstone floor characterized by rheological, swelling and softening property, the roadway in Ma Jialiang Mine soft coal seam encounters heavy rock surrounding support problems of roof sag and floor heave. Consequently, the safe and orderly production was affected seriously. Taking the main air return way as a primary research object, the paper has studied the law of surrounding rock deformation and failure, reasonable section size and shape, support parameters and floor heave control method by means of field measurement, theoretical analysis, numerical simulation and so on. The research shows that micro cambered arch roof, drain-pipe installed in roof, inverted-arch floor, net and bolt support of whole section are the optimum combination of section form and support scheme. The field application tells that the optimized air return way surrounding deformation can be controlled effectively, which meets the requirements of keeping it stable for a long period. The achievements of this research will offer useful data for large section roadway support in soft coal seam.


Wu F.,China University of Mining and Technology | Yang J.,China University of Mining and Technology | Yu B.,China University of Mining and Technology | Yu B.,Datong Coal Mine Group Company | Chen X.,China University of Mining and Technology
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2014

In order to study the caving height of goaf roof of thick and extra thick seams, a comprehensive method including theory analysis, numerical calculation, physical simulation and field measurement is used. Results show that the key strata theory can be used for the hard and structural integrity roof. The calculation method of the gob roof caving height, which considers the effects of the roof deflection and the gangue broken expansions, is generally applicable, and the gob roof caving height is found to be impacted by mining thickness, the bulk increase coefficient of broken block in the roof and the limit amount deflection of the mine roof. The caving height of the No. 8105 working face hard roof of Datong Mine Tongxin coal mine are calculated as 143 m and 76-141 m by two theoretical analyses, and the field measurement is 80-120 m, indicating the applicability of these two methods.


Yu B.,Datong Coal Mine Group Company | Liu C.,China University of Mining and Technology | Liu J.,Datong Coal Mine Group Company
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2014

To ensure the stability and working of the advance supported roadway on gob side at the extra-thick seam zone during the mining process in Datong mine, a combined method of theoretical analysis and field measurement was used to obtain the pressure behavior of the forepoling segment of the roadway. The results of the research showed that the depths affected by the stress concentration zone of the coal pillar at mined-out section of Jurassic period were only 50-70 m, not deep enough to affect the occurrence of the strata pressure at the working face of the advance supported roadway in Carboniferous period. The occurrence of the strong strata pressure at the advance supported roadway in Carboniferous period was mainly affected by the abutment pressure due to mining and the high bearing pressure of overhang roof on two sides of the adjacent mined-out area. When the working front passed the boundary pillar of the mined-out area of the overlying coal, the big seam roof structure in Jurassic period was reactivated and tended to be unstable again, which speeded up the occurrence of the strong strata pressure of the roadway approaching the mined-out area. An effective control technology with the orientated high-pressure hydraulic fracturing of roadway roof was proposed and applied to the working front 8105 in the roadway 5105 approaching the mined-out area in Tongxin mine. The technology achieved the high stress transfer in the surrounding rock of roadway and greatly reduced the strong strata pressure of advance supported roadway approaching mined-out area.


Yu B.,China University of Mining and Technology | Yu B.,Datong Coal Mine Group Company | Liu C.-Y.,China University of Mining and Technology | Yang J.-X.,China University of Mining and Technology | Liu J.-R.,Datong Coal Mine Group Company
Zhongguo Kuangye Daxue Xuebao/Journal of China University of Mining and Technology | Year: 2013

The condition of hard and thick roof in Jinhuagong Mine serves as a case in point. By means of theoretical analysis and in-site testing, this paper studied the critical instability conditions, instability modes, factors influencing instability, and mechanism of instability, and proposed the technique that controlled the instability of hard and thick roof. The results show that: the property and occurrence condition of rock have a vital influence on the load bearing of broken hard-and-thick roof; the development of instability of broken hard-and-thick roof is influenced by the broken length of roof, however it is limited to improving the control of the support intensity on the roof fracture instability; the study also proposes the roof control method that pre-splitting blasting of hard and thick roof reduces the length of roof fracture, and properly selection of support improves the intensity of it. Through the application in 8210 working face of Jinhuagong Mine, the end and time weighted resistances accounted for 85.3% and 83.7% of the rated working resistance, respectively. The roof immediately collapsed with the mining advance, and the coal spalling depth was controlled in the range of 0.2-0.3 m.

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