煤矿采区瓦斯抽放系统设计及应用

当工作面瓦斯浓度较高,采用通风方法无法解决时,必须建立瓦斯抽放系统实施瓦斯抽放.针对郑煤集团芦沟煤矿的32101采煤工作面瓦斯浓度较高的情况,设计了采煤工作面瓦斯抽放系统,具体包括管路敷设路线、管径、瓦斯抽放泵、抽放孔布置和参数以及相应安全技术措施.应用表明,该瓦斯抽放系统有效地降低了32101工作面瓦斯涌出量,保证了该采煤工作面的安全生产.     

中国采煤工作面瓦斯涌出规律及其控制研究

将采煤工作面瓦斯来源划分为煤壁、采落煤和采空区３部分,并给出了各部分瓦斯涌出量的计算公式,研究了回采过程,煤层群不同的开采顺序以及厚煤层分层开采时的瓦斯涌出 述了中国煤矿采矿工作面采用不同的通风系统、脉冲通风以及瓦斯抽放等控制瓦斯涌出的原理与技术的新成果,介绍了瓦斯涌出量达１５０ｍ＾３／ｍｉｎ的综采放顶煤工作面瓦斯控制技术实例。     

九里山矿14区放顶煤开采瓦斯涌出规律分析

分析了焦作矿务局九里山矿放顶煤工作面沿底掘进及开采期间各生产工序瓦斯涌出规律． 与顶分层开采对比, 放顶煤开采相对瓦斯涌出量降低, 绝对瓦斯涌出量增加倍数小于产量提高倍数, 各生产工序以放煤时瓦斯涌出量最大; 沿顶掘巷的平均瓦斯涌出量是沿底掘巷的１ ．２５ 倍, 沿底掘进不增加突出危险性     

九里山矿14区放顶煤开采瓦斯涌出规律分析

分析了焦作矿务局九里山矿放顶煤工作面沿底掘进及开采期间各生产工序瓦斯涌出规律.与顶分层开采对比,放顶煤开采相对瓦斯涌出量降低,绝对瓦斯涌出量增加倍数小于产量提高倍数,各生产工序以放煤时瓦斯涌出量最大;沿顶掘巷的平均瓦斯涌出量是沿底掘巷的1.25倍,沿底掘进不增加突出危险性.     

漳村煤矿设瓦斯巷综放面瓦斯分布及涌出特征

由于综放工作面开采强度大,引起瓦斯涌出量成倍增加,严重制约着工作面的安全生产．针对瓦斯涌出强度大的问题,通过在山西潞安矿务局漳村煤矿综放工作面布置测点、测线,进行现场观测和研究,分析论述了工作面设置排放瓦斯巷解决瓦斯严重超限问题时,综放工作面的瓦斯分布状况及涌出特征．     

焦作九里山矿单体支柱放顶煤工作面顶煤运动放出规律浅析

通过焦作矿务局九里山矿单体支柱放顶煤工作面现场实测, 得出单体支柱放顶煤工作面顶煤运动、破碎、放煤过程中煤流动态及放出椭球体规律, 为确定合理放顶煤工艺参数提供了可靠的依据． 合理的放煤工艺参数不但提高了回收率, 而且保证了工作面正常生产, 这对焦作矿区今后采煤方法的改革具有重要的指导意义     

焦作九里山矿单体支柱放顶煤工作面顶煤运动放出规律浅析

通过焦作矿务局九里山矿单体支柱放顶煤工作面现场实测,得出单体支柱放顶煤工作面顶煤运动、破碎、放煤过程中煤流动态及放出椭球体规律,为确定合理放顶煤工艺参数提供了可靠的依据.合理的放煤工艺参数不但提高了回收率,而且保证了工作面正常生产,这对焦作矿区今后采煤方法的改革具有重要的指导意义.     

鹤壁矿区瓦斯综合治理技术研究

分析并研究了鹤壁矿区瓦斯涌出规律,阐述了鹤壁矿区瓦斯综合治理基本方法,提出了以瓦斯抽放和通风方式改革为主的瓦斯综合治理技术.对回采工作面提出采用综合抽放、进行采区通风方式改革、选择合理的采煤工艺等技术;对于掘进工作面提出了边掘边抽、大力推广应用对旋式风机等综合治理技术,指明了鹤壁矿区未来瓦斯治理技术的发展方向。     

鹤壁矿区瓦斯综合治理技术研究

分析并研究了鹤壁矿区瓦斯涌出规律 ,阐述了鹤壁矿区瓦斯综合治理基本方法 ,提出了以瓦斯抽放和通风方式改革为主的瓦斯综合治理技术 .对回采工作面提出采用综合抽放、进行采区通风方式改革、选择合理的采煤工艺等技术 ;对于掘进工作面提出了边掘边抽、大力推广应用对旋式风机等综合治理技术 ,指明了鹤壁矿区未来瓦斯治理技术的发展方向     

综采放顶煤与瓦斯突出的耦合关系研究

对煤与瓦斯突出发生的综合作用机理及治理技术进行总结,从宏观上提出治理煤与瓦斯突出的技术手段;分析总结我国综采放顶煤开采的技术成果,讨论了工作面应力分布规律和顶煤变形规律对突出的影响;认为:具突出危险性的厚煤层采用综采放顶煤开采法对消突是有积极作用的.     

Top coal flows in an excavation disturbed zone of high section top coal caving of an extremely steep and thick seam

Compared with gentle dip long-wall caving, the length of a working face in fully-mechanized top-coal caving for extremely steep and thick seams is short, while its horizontal section is high with increasing production. But the caving ratio is low, which might result in some disasters, such as roof falls, induced by local and large area collapse of the top coal in a working face and dangers induced by gas accumulation. After the development of cracks and weakening of the coal body, the tall, broken section of the top coal (a granular medium) of an extremely steep seam (over 60°) shows clear characteristics of nonlinear movement, We have thoroughly analyzed the geological environment and mining conditions of an excavation disturbed zone. Based on the results from a physical experiment of large-scale 3D modeling and coupling simulation of top coal-water-gas, we conclude that the weakened top coal can be regarded as a non-continuous medium. We used a particle flow code program to compare and analyze migration processes and the movements of a 30 m high section top coal over time before and after weakening of an extremely steep seam in the Weihuliang coal mine. The results of our simulation,experiment and monitoring show that pre-injection of water and pre-splitting blasting improve caving ability and symmetrical caving, relieve space for large area dynamic collapse of top coal, prolong migration time of noxious gases and release them from the mined out area and so achieve safety in mining.     

Technical parameters of drawing and coal-gangue field movements of a fully mechanized large mining height top coal caving working face

Under fully mechanized, large mining height top coal caving conditions, the shield beam slope angle of the support increases due to the enlargement of the top coal breaking and caving space. This results in a change of the caving window location and dimensions and, therefore, the granular coal-gangue movement and flows provide new characteristics during top coal caving. The main inferences we draw are as follows. Firstly, after shifting the supports, the caved top coal layer line and the coal gangue boundary line become steeper and are clearly larger than those under common mining heights. Secondly, during the top coal caving procedure, the speed of the coal-gangue flow increases and at the same drawing interval, the distance between the coal-gangue boundary line and the top beam end is reduced. Thirdly, affected by the drawing ratio, the slope angle of the shield beam and the dimensions of the caving window, it is easy to mix the gangue. A rational drawing interval will cause the coal-gangue boundary line to be slightly behind the down tail boom lower boundary. This rational drawing interval under conditions of large mining heights has been analyzed and determined.     

Structure and deformation measurements of shallow overburden during top coal caving longwall mining

Mining induced pressures are strong and overburden failure areas are large in top coal caving longwall mining, which constrains high production and safety mining. By employing the combination of the full view borehole photography technique and the seismic CT scanner technique, the deformation and failure of overlying strata of fully mechanized caving face in shallow coal seam were studied and the failure development of overburden was determined. Results show that the full view borehole photography can reveal the characteristics of strata, and the seismic CT scanner can reflect the characteristics of strata between the boreholes. The combined measurement technique can effectively determine the height of fractured and caved zones. The top end of the caved zone in Yangwangou coal mine employing the top coal caving longwall mining was at the depth of 171 m and fractured zone was at the depth of 106-110 m. The results provide a theoretic foundation for controlling the overburden strata in the shallow buried top coal caving panel.     

Analysis of stability of support and surrounding rock in mining top coal of inclined coal seam

The study analyzes the characteristics of roof movement in mining top coal of inclined coal seam, and establishes the mechanical model of support and surrounding-rock stability in inclined coal seam. Besides, this study carries out the numerical calculation and field observation of roof movement and support stability, and provides the critical control measures. The results show that the fracture firstly appears in middle-upper roof and extends upwards in top coal caving in inclined coal seam; regular and irregular caving zones appear in middle-upper stress concentration region, and the asymmetric caving arch is finally formed. Support load of middle-upper working face is larger than that of the middle-lower face; dynamic load coefficient of upper support is large, and the load on the front of support is larger than that on the rear of it, which leads to poor support stability. Stability of support and surrounding-rock system depends mainly on upper-support stability.     

综放开采不同顶煤端面顶板稳定性及其控制

采用离散元程序 UDEC模拟分析了不同顶煤条件下端面顶板的稳定性与支架工作阻力及端面距的关系 .模拟结果表明 ,在软及中硬煤条件下 ,在一定的端面距范围内 ,支架工作阻力与端面顶板下沉量呈类双曲线关系 ;而在硬煤条件下没有类似关系 .并据此提出了端面顶板控制原则 ,认为在软煤条件下最重要的是控制端面距 ,在中硬煤条件下在于端面距与支架工作阻力的合理匹配 ,而在硬煤条件则应以提高顶煤冒放性为重点 .上述结论成功地运用于现场端面顶煤稳定性的控制 .     

Application of open-pit and underground mining technology for residual coal of end slopes

Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining technology for residual coal of end slopes.In the proposal a conveyance road and ventilation conveyance near the slope are built,corresponding to the pit mining area and the surface coal mine dump,as well as an interval haulage tunnel and air-inlet tunnel.The outcome shows that such mining method may reduce the effect to slope stability from underground mining,it does not affect the dumping advance and has a high recovery rate of residual coal resources.The working face is timbered by single hydraulic props,transported by a scraper conveyor and supported by coal walls.This method of mining is one of layered top coal caving,with high resource recovery,low production cost where positive economic benefit can be realized.     

高瓦斯综放采煤工作面瓦斯综合治理方案

针对佳新煤矿1504综放工作面瓦斯的实际情况,分析了该工作面的瓦斯主要涌出来源及涌出量,结合该矿通风系统及瓦斯抽采现状,在上下顺槽顺层、上隅角、措施巷道等采用钻孔、高位钻场、埋管、吊管多种方式抽放,以及增加工作面风量和局部风机对上隅角供风等综合措施治理瓦斯,从而解决了上隅角及回风巷瓦斯超限问题,确保了工作面安全高效生产,真正实现了高瓦斯综放工作面的高产高效。     

Huge thick conglomerate movement induced by full thick longwall mining huge thick coal seam

A discrete elemental method was used to study the thickness of conglomerate layer in a full thick seam mining activities under the influence of the law, pointing out the thickness of the conglomerate at different seam mining, and during the destruction and instability of existing state of laws. At 21141 thick seam mining, the face toward the direction of separation between the thick layer of conglomerate rock and the next bit after reaching its maximum capacity due to pull from the bottom of the plastic zone, formed a stratified and hierarchical down collapse. The shape of caving area is a “triangular block”, the length of the plastic zone and face advancement from the linear fit between the height of the plastic zone and the advancing face is a quadratic function of distance, while the top layer of thick gravel layer is the overall bending subsidence trend. Tilting the direction of the face, a thick gob of collapsed conglomerate layer is formed in the coal gob entity on both sides of the thick conglomerate at the top of the overall fracture morphology performance, thus forming a mutual extrusion of articulated block structure. The instability, separation and balance of the thick conglomerate layer in the hinged block stope stress leads to abnormal occurrence of rock burst induced by face as the major factor in the accident. This research reveals the form of stress distribution in the destroyed layer of the thick conglomerate rock, analyzes the stope law of coupling for the pressure burst behavior law for the mining work face, and the choice of preventive measures to provide a theoretical basis and implementation.     

Development of 3D top coal caving angle model for fully mechanized extra-thick coal seam mining

During high-intensity, fully mechanized mining of extra-thick coal seam, the top coal would cave to a certain 3D form. Based on the data collected during drilling, a 3D model of top coal caving surface space was established to determine the relationship between the location of the stope roof and the caving surface, enabling the mathematical computation of the top caving angle (φ). The drilling method was employed to measure the top caving angle on two extra-thick fully mechanized coal caving faces under the conditions of three geological structures, namely, no geological structure, igneous rock structure, and fault structure. The results show that the value of top caving angle could be accurately estimated on-site with the 9-parameter 3D top coal caving surface model built with the drilling method. This method is a novel on-site measurement that can be easily applied. Our findings reveal that the characteristics of the coal-rock in the two mining faces are different; yet their caving angles follow the rule φ_{igneous rock structure} < φ_{no geological structure} < φ_{fault structure}. Finally, through the data fitting with two indexes (the top coal uniaxial compressive strength and the top caving angle), it is found that the relationship between the two indexes satisfies an exponential decay function.