Back-and-forth mining for hard and thick coal seams—research about the mining technology for fully mechanized caving working face of Datong Mine

The article introduced the key technology, mining process, and back-and-forth mining method for the caving working face of hard-thick coal seams in Datong mine, and researched this innovations process, optimized the systemic design and working face out-play, tried to perfect the caving mining technology of hard-thick coal seams further.

Analysis and key control technologies to prevent spontaneous coal combustion occurring at a fully mechanized caving face with large obliquity in deep mines

In order to prevent spontaneous coal combustion occurring at a fully mechanized caving face with large obliquity in deep mines in China,we have analyzed the characteristics of spontaneous coal combustion and explain theoretically the factors affecting spontaneous coal combustion,such as rock bursts,high temperatures,high ventilation resistance,slow advancing speed and large obliquity mining.Key technologies to prevent spontaneous combustion occurring in sharply inclined seams in deep mines are proposed;these include pouring water,stopping leakage in upper and lower corners of the working face,choking off the goaf and covering the coal.CO concentrations were controlled within two years to less than 15×10-6 at the upper corner by applying these technologies at the 1410 working face of the Huafeng coal mine.Our method has significant theoretical value and is of practical importance in controlling spontaneous coal combustion occurring at a fully mechanized caving face with large obliquity in deep mines.

Similar material simulation research on movement law of roof over-lying strata in stope of fully mechanized caving face with large mining height

Similar material simulation test was carried out in a geological model ofW_(9-15)101 fully mechanized caving face with large mining height in the Liuhuanggou Colliery,in Xinjiang Uigur Autonomous Region.The roof overlying strata movement law in thestope of a fully mechanized caving face with large mining height was studied and showthat the roof overlying strata in the stope of a fully mechanized caving face with large miningheight can be formed into a stable arch structure; the fracture rock beam is formed resemblinga 'bond beam', but it has essentially the structure of 'multi-span beams' underthe big structure of the stable arch.The roof overlying strata movement law in the stope ofa fully mechanized caving face with large mining height is similar to that of the common,fully mechanized caving stope, which is determined by the deformation and instability ofthe structure of 'multi-span beams'.But because of the differences between the miningheights, the peak pressure in the stope of a fully mechanized caving face with large miningheight is smaller while the affected area of abutment pressure is wider in the front of theworking face; this is the obvious difference in abutment pressure between the stope of afully mechanized caving face with large mining height and that of the common.

Surface Movement Regularity of Super-Wide Mining Face With Top-Coal Caving

No.4326 super-wide panel of Wangzhuang Coal Mine ( in which the fully-mechanized top-coal caving longwall mining method was used) was monitored for dynamic characteristic of surface movement. The dynamic surface movement in and after mining was predicted by using the Mining Subsidence Prediction System. The results indicate that after mining, the surface above the super-wide panel reaches a state of full subsidence, making the No.309 national highway above the panel be located on the flat bottom of the subsidence basin so that the influence of mining activity in both sides of 4326 panel on the national highway is the smallest.

Ground pressure and overlying strata structure for a repeated mining face of residual coal after room and pillar mining

To investigate the abnormal ground pressures and roof control problem in fully mechanized repeated mining of residual coal after room and pillar mining,the roof fracture structural model and mechanical model were developed using numerical simulation and theoretical analysis.The roof fracture characteristics of a repeated mining face were revealed and the ground pressure law and roof supporting conditions of the repeated mining face were obtained.The results indicate that when the repeated mining face passes the residual pillars,the sudden instability causes fracturing in the main roof above the old goaf and forms an extra-large rock block above the mining face.A relatively stable ‘‘Voussoir beam" structure is formed after the advance fracturing of the main roof.When the repeated mining face passes the old goaf,as the large rock block revolves and touches gangue,the rock block will break secondarily under overburden rock loads.An example calculation was performed involving an integrated mine in Shanxi province,results showed that minimum working resistance values of support determined to be reasonable were respectively 11,412 kN and 10,743 kN when repeated mining face passed through residual pillar and goaf.On-site ground pressure monitoring results indicated that the mechanical model and support resistance calculation were reasonable.

STUDY ON PRODUCTION SYSTEM OPERATION REGULARITY OF FULLY MECHANIZED SUBLEVEL CAVING MINING AND SEQUENTIAL OPERATION

According to a lot of practical data in Liujialiang Mine and reliability theory and result of computer simulation, operation regularity of fully mechanized sublevel caving mining production system in the condition of gently inclined complicated geological structure and production shortcomings are found out and reliability of system and output of the working face are predicted finally.

两次采动影响下小煤柱巷道切顶卸压围岩控制技术

为解决多次采动影响下留小煤柱巷道矿压显现剧烈、围岩变形量大的问题,提出了“切顶卸压+顶、帮锚索补强”联合控制技术。以贾家沟煤矿10115运输巷为工程背景,分析了切顶卸压位置、高度与巷道围岩垂直应力分布的关系,给出切顶卸压关键参数,并研究了留小煤柱巷道在切顶卸压后受两次采动影响下的矿压显现规律。结果表明:切顶卸压后,煤柱上的应力峰值随切顶深度的增加呈指数降低;10115运输巷在邻近工作面一次采动过程中巷道围岩变形依次呈现出无变形、缓慢变形、快速变形和围岩稳定的变化规律,本工作面二次采动过程中巷道围岩变形依次呈现出明显变形和剧烈变形的规律;巷道围岩在受二次采动影响时变形更加剧烈,巷道变形量为一次采动时的3.0~7.5倍。

近距离煤层厚硬顶板综放开采强矿压显现规律研究

针对厚硬顶板大采高综放工作面回采过程中强矿压的现象,以神东矿区某矿井近距离煤层厚硬顶板综放工作面为背景,通过现场实测和室内试验等方式,研究工作面矿压显现规律及覆岩破断特征。研究表明:(1)42105综放工作面老顶初次来压步距大,来压强度高,远超工作面支架额定工作阻力,工作面呈现出中部来压集中、强度高且较为频繁的特征;(2)近距离厚硬顶板下回采工作面时,重复采动下工作面覆岩破坏高度更大,尤其是上位关键层破断后带动下位关键层同时破断,并带动其控制的上覆岩层及上方采空区同步下沉,岩层载荷逐层向下传导至工作面,上下位关键层破断的协同作用,从而造成了工作面来压强烈。

山西五家沟煤矿深孔强制放顶爆破方案设计

本文通过对山西五家沟煤矿回采工作面工程概况和地质水文状况进行分析,应用深孔爆破强制放顶技术原理,合理设计出该矿回采工作面的深孔爆破方案,后期又设计出新型分段式装药爆破试验方法,为安全高效地完成该矿的生产任务提供了有力的技术支持。

煤矿大倾角综放工作面采煤参数及采煤工艺优化分析

以A煤矿26514工作面为例,介绍了一种基于有限元分析的煤矿大倾角综放工作面采煤参数及采煤工艺优化方法。该方法根据煤矿大倾角综放工作面参数构建相应的有限元模型,通过有限元模型的分析寻找现有工作面采煤参数与采煤工艺的缺陷,进而以此为基础制定工作面采煤参数与采煤工艺优化方案。研究对大倾角综放工作面的开采具有重要意义。

新景矿综采工作面自燃“三带”范围分布规律研究

山西新景矿15317综放工作面属于Ⅱ类自燃煤层,为确保安全推进速度,需要对采空区自燃“三带”进行测定。此次测定利用煤自然发火临界氧浓度指标来划分,采用束管监测监控技术对15317综放工作开采期间采空区氧气浓度进行了实测,并据此对采空区自燃“三带”进行了划分,同时计算了工作面的最小安全推进速度,为工作面安全开采提供了数据支持。

特厚煤层综放面硫化氢运移特征研究

针对现阶段采用单一方法研究特厚煤层综放面硫化氢浓度运移规律,无法有效指导现场开展硫化氢治理工作,在山西吕梁庞庞塔煤矿开展试验研究。沿着工作面垂直方向、水平方向和风流方向布置现场测点,通过CD4型多参数测定器测定工作面硫化氢浓度;借助Fluent数值模拟软件建立几何模型,分析该工作面硫化氢运移规律。现场实测结果和模拟结果表明:沿着巷道垂直方向,硫化氢浓度伴随与巷道底板高度的增大先升高后下降;沿着工作面水平方向,硫化氢浓度伴随与煤壁距离增大而逐步下降;沿着工作面风流方向,硫化氢浓度随逐渐远离采煤机而逐步下降。

工作面停采煤柱宽度的确定与实践

燕子山矿采用宽煤柱方式护巷,煤柱宽度约60 m,造成资源的严重浪费。通过对回风巷的受力变化规律进行监测分析,得出工作面回采对巷道压力影响的临界距离为35 m。以此为依据,在综合考虑8210工作面特殊性的基础上,分析得出该工作面最佳停采煤柱宽度为38~45 m。为检验8210工作面煤柱宽度,该矿在回风大巷开展了顶板钻孔窥视工作,检测顶板煤层回采期间和停采后的变化情况,窥视检测结果表明,工作面留设38~45 m煤柱宽度能够保证巷道围岩的稳定性,是安全可靠的。

综放工作面端面冒顶机理与围岩控制技术研究

针对9102综放工作面在回采过程中端面顶板破碎等围岩支护难题,首先对工作面的工程概况及顶底板条件进行分析,重点分析了采场围岩支护难点及端面冒顶机理,然后在具体回采经验的基础上,设计了9102综放工作面采场围岩控制体系,然后进行了现场实践及效果分析,工作面推采过程中仅发生局部轻度片帮冒顶事故,端面煤岩体整体稳定程度较高,安全生产工作得到保障。

综放工作面小煤柱沿空掘巷煤柱尺寸留设研究

为合理留设综放工作面沿空掘巷煤柱,以山西某矿E4102-1工作面运输顺槽煤柱留设工程概况为例,通过进行调研分析与进行数值模拟分析,并结合工业性试验,得出窄煤柱沿空掘巷技术目前已相对较成熟,可把煤柱尺寸留设为5 m至8 m之间;通过对几种煤柱尺寸下的巷道围岩破坏状况进行数值模拟分析,得出该工作面巷道留设5 m宽的煤柱时,该巷道矿压不会出现明显显现,巷道变形量相对较小,巷道顶板也相对较稳定,能很好的满足矿井安全生产需求,更好地保障矿井安全生产。

袁大滩煤矿超长工作面覆岩两带发育规律研究

针对超长工作面采动影响下覆岩两带发育规律,以袁大滩煤矿工作面为背景,采用理论分析与离散元的3DEC数值计算软件相结合的方法,研究该条件下覆岩裂隙的分布特征与两带发育规律。结果表明,根据理论计算,得到2号煤层工作面不同采高下2种经验公式的两带发育高度,得出随着工作面采高的增加,工作面采后的导水裂隙带高度逐渐增加,但其裂隙高度的递增幅度逐渐减小的规律;通过3DEC数值模拟,11207超长工作面采高每增加0.2 m所得导水裂隙带高度约增加2.01~3.05 m,超长工作面采高越大,开采高度增加引起裂隙发育高度增幅越小。数值模拟与理论计算基本一致且相互印证。工作面实际开采过程中工作面的开采高度逐渐减小,裂隙带发育高度逐渐降低,覆岩位移量逐渐减小,集中应力逐渐减弱,开采初期需要加强监测,增强防护措施。

81104工作面过构造区域开采方案优化分析

根据阳煤二矿81104综放工作面构造预测及钻探结果,判定工作面内褶曲构造发育;结合工作面煤层变化趋势、顶底板岩性及机组割岩能力等方面分析,该构造对工作面正常回采影响较大区域为1 050~1 250 m(进风侧0~100 mm范围内);拟定“硬过构造区域”、“构造区整体跳采”、“构造区绕巷跳采”三种过构造开采方案进行比较,即从矿井生产、技术、通风、经济效益等方面进行综合分析后,认为“绕巷跳采”方案准备时间最短、经济效益最好,为最优方案。

综放工作面智能化升级改造与应用

智能化不仅是煤矿转型升级的新途径,也是新时代背景下煤炭开采技术革新的前进方向,更是煤炭工业高质量发展的必由之路。以山西中煤东坡煤矿915综放工作面为智能化升级改造对象,结合工作面开采技术条件和现场设备实际配置情况,按照智能化采煤工作面建设指南及验收管理办法的相关要求,在合理控制投资的前提下提出了具有针对性的中级智能化综放工作面改造目标、系统架构和升级方案,完成了对采煤、支护、供液、人员定位及视频监控等子系统的智能化升级。升级改造后实现了工作面采煤机记忆截割、支架一键放煤、自动跟机、实时视频监控、地面及井下远程可视化控制、各系统协同控制等功能,达到了“增安、减人、提效”的目的,对类似条件下智能化采煤工作面建设具有一定的参考意义。

老空老巷富集孤岛面末采及撤除防火技术

随现阶段国家矿山安全监察局对煤矿CO气体管控更加严格,对于自然发火矿井工作面撤除是易发火和难防火的关键阶段,为保证综放工作面在末采及撤除期间无自然发火隐患,打破以往“逢拆必着”的防火被动局面,通过对常村煤矿2012年以来8个撤除工作面的防火工作进行梳理和总结,因地制宜,采取完善防火措施,升级防火装备,强化人员组织,落实管控效果等手段,对末采及拆除防火技术进行优化创新并在21002撤除面得到检验,保证工作面安全顺利回撤,实现架间及回风流CO零管控,并减少防火费用投入,使得矿井撤除防火技术和经验在整个集团公司得到推广和应用。