老空区积水作为诱发煤矿水害事故的主要突水水源,严重制约着井下煤矿资源的开采.为解决传统探放水方法面临的精度低、探放水钻孔距离短等难题,设计了一种长距离定向钻孔穿多煤层群精确探放水技术方法,为实现煤矿井下采空区积水探放与上覆含水层的预防治理工程提供了新的技术手段,设计了长距离定向钻孔穿多煤层群精确探放水系统与装备构成,确定了长距离定向钻孔穿多煤层群精确探放水技术关键参数与工艺流程,并以榆树岭煤矿东翼下 5 煤层老空水防治为工程背景,设计并应用了长距离定向钻孔穿多煤层群精确探放水方案,工程实践表明:经过探水与疏放水两个阶段,累计疏放老空水约3.535×105 m3,老空区静态积水疏放结束,仍存在约 26 m3/h的动态补给水,为老空区积水的疏放和长期治理提供了有效途径,为后期工作面的采掘布置提供安全保障,为类似条件下煤矿探放水工程设计提供依据与参考.
针对综放采动影响下回采巷道的超前支护段围岩应力分布及变形特征,分析工作面四周支承压力分布规律,确定超前支护强度、支护距离.文章结合东周窑煤矿 8107 综放工作面回采巷道的地质及生产技术条件建立了理论模型,得到了运输巷在采动影响下的围岩应力分布及顶板垂直位移规律;通过理论分析工作面前后支承压力分布规律,建立极限平衡理论模型,推导了超前支护距离理论计算公式.
针对 3506 综采工作面沿空留巷期间采空区遗煤自然发火危险性大的问题,结合现场情况制定以减少漏风、注氮、灌浆以及强化监测为主的防灭火技术措施,并进行工程应用.通过留巷段缝隙封堵及喷浆、地面漏风裂隙封堵以及采面上下端头砌筑挡墙等方式减少采空区内漏风量;回采期间综合人工监测、安全监控系统以及束管监测等方式实现采空区遗煤自然发火预警;当有自然发火征兆时即快速进行注氮、灌浆.现场应用后,3506 综采工作面回采期间回风流中CO体积分数最高控制在 10×10-6 以内,采空区遗煤自然发火问题得以较好解决,采用的防灭火技术措施可为采面煤炭安全高效回采创造良好条件.
为提高干河煤矿 3 号煤层三采区资源利用率,进行高水速凝材料巷旁充填沿空留巷技术应用试验,综合运用理论分析、工程类比、数值模拟等手段,设计巷旁充填体规格及留巷支护方案.研究表明:2-301 运输巷巷旁充填体合理宽度为 2.2 m,留巷稳定后围岩变形量可控,留巷工艺较新掘巷道可增加利润 11352.3 元/m,取得了较好的安全、经济、社会效益.
为保障两渡煤业断层构造区域回采巷道掘巷阶段围岩稳定,通过数值模拟、矿压监测等方法,预测了矿井典型煤巷支护方案的围岩控制效果.研究表明:与断层距离 20～30 m处巷道开挖时,围岩塑性破坏区基本呈对称分布,不受断层构造影响;与断层距离 5～15 m处巷道开挖时,断层构造对巷道围岩稳定造成明显的不利影响,结合 29(10)01 运输巷道与F3 断层位置条件,提出针对性优化支护方案,实践阶段综合矿压监测表明,设计支护方案及参数合理有效.
31103 运输巷在顶板破碎、松动破坏范围大、围岩承载能力差以及围岩支护参数不合理等多重因素影响下呈现顶板离层量大、支护困难以及围岩变形严重等问题.结合 31103 运输巷现场条件,提出采用锚网索+注浆+喷浆方式支护,综合使用超前注浆、围岩喷浆、长锚索以及滞后注浆方式实现破碎顶板巷道围岩加固、支护.现场应用后,运输巷顶底板、巷帮变形量分别控制在89 mm、148 mm以内,围岩变形量较小,可满足巷道掘进及后续使用需求.
为解决山西省某矿 3210 回风巷掘进区域煤与瓦斯突出威胁,设计采用长距离定向钻孔预抽该区域瓦斯,综合运用数值模拟、理论分析等方法,确定定向钻孔合理直径 96 mm、抽采负压 25 kPa、抽采时间120 d,结合工作面生产地质条件设计钻场及定向钻孔布置方案,实践表明,为期 120 d瓦斯预抽期间抽采浓度大于 50%,抽采率达到 58.5%,取得较好消突效果.
针对厚硬顶板工作面推进至停采线时,导致前方采区大巷围岩变形失稳的问题,提出了采用静态破碎切顶技术,并通过理论分析了多孔叠加下的膨胀破碎机理和化学反应过程,随后结合相关地质条件确定了切顶关键参数且数值计算验证了方案的卸压效果良好.现场应用效果表明:静态破碎切顶后,辅运大巷处顶底板移近量为0.81 mm/d,较之切顶前减少了91.4%,两帮移近量为0.86 mm/d,较之切顶前减少了79.5%,表明静态破碎切顶卸压可有效缩小超前动压影响范围,改善辅运大巷围岩应力环境.
转载点连续抛煤产生大量粉尘,对工人健康和企业生产有严重威胁.文章分析了店坪矿采煤面转载点粉尘防治现状,认为粉尘主要由于上胶带煤流抛落至下胶带时的冲击碰撞所致.原有水幕降尘后呼吸性粉尘和总粉尘残余质量浓度高达 152.4 mg/m3 和 58.3 mg/m3.对转载点进行密闭除尘改进,使用密闭罩和全自动喷雾装置除尘后,呼尘和全尘质量浓度降至 6.4 mg/m3 和 2.1 mg/m3,降尘率分别为 96.8%和97.5%.
为控制回采巷道顶板及两帮变形,提出注浆锚索高强支护方式以达到对巷道围岩变形控制的目的.通过运用ANSYS有限元分析软件,对锚岩体应力进行分析,确定最佳锚索支护预紧力、间排距及长度.在此基础上,分析注浆原理、施工工艺等,并结合现场实际应用.结果 表明:锚索间排距和预紧力直接影响锚岩体应力分布及支护效果;注浆锚索能够显著降低巷道围岩变形量,满足围岩变形安全要求值,断面尺寸满足回采要求,对提高围岩稳定性至关重要.
针对 3301 综放工作面回采期间粉尘产生量大、现场粉尘污染严重等问题,提出通过注水、喷雾方式进行综合降尘,并结合现场情况具体给出注水、喷雾系统布置方案.由于回采的 3 号煤层厚度大、原始含水率低,采用高压脉冲方式对煤层进行注水,最大注水压力控制在 7.5 MPa,避免注水期间引起煤层顶底板破碎;通过在采煤机、液压支架上增设喷雾装置,提高割煤、移动及放煤等环节粉尘控制效果,并抑制产尘点粉尘外溢量.采面综合降尘技术工程应用后,采煤机司机及放煤支架后方 3m位置全尘质量浓度分别降至 121 mg/m3、97 mg/m3,降尘效率分别达到 83.87%、80.52%,现场应用效果显著.
某矿 11303 综采工作面回采期间揭露有多条断层,在断层及地应力等多因素影响下煤层顶板破碎,加之顶板本身承载能力低、性脆,采面回采期间出现架间漏矸、漏顶问题,给煤炭安全回采造成较大影响.为此,文章提出采用超前注浆方式加固断层影响区煤体及破碎顶板,提高煤岩体整体稳定性及承载能力;采用铺设双层网避免漏矸,同时为避免"网兜"形成,在双层网下穿管子,一节管子覆盖至少 3 个液压支架,并采用交错拉架方式确保管子始终撑起网片;强化采面三机直线度管理,避免支架出现挤架、错台或者咬架等影响顶板稳定及开采问题.生产实践表明,工作面回采过断层期间顶板及煤壁始终保持稳定,未有架间漏矸或者漏顶等情况发生,为煤炭安全回采创造了良好条件.
煤层顶板岩层破断角的大小是影响顶板垮落形态和矿山压力的重要参数.为分析屯兰矿煤层开采时顶板压力大小,合理选用液压支架,在 12509 工作面辅助运输巷布置了 3 个观测站对煤层顶板岩层的破断角进行了探查,最终测的煤层顶板以上 10～20 m和 10～30 m的基岩破断角平均值分别为 68.9°和63.9°,为计算工作面顶板压力大小和液压支架选型提供了依据.
山西高河能源有限公司"三下"压煤十分严重,为响应国家"安全高效、绿色环保、稳定可靠、节俭和谐"的号召,基于绿色充填开采,提出了综合机械化膏体充填开采.综合机械化膏体充填开采分为一次采全高综合机械化膏体充填开采和分层膏体充填开采.经过科学论证表明,高河煤矿更适合综合机械化膏体充填采煤方法分层方案,并且该充填方案的预测地表沉陷变形量在村庄建构筑物的允许范围内.
针对厚硬顶板沿空巷道切顶参数不合理导致的工作面悬顶及巷道围岩变形问题,文章采用理论分析、数值模拟与现场监测相结合方法对沿空巷道切顶参数优化及围岩控制方法进行了研究.结果表明:厚硬基本顶未切顶部分所受拉应力大小与切顶高度及切顶角度密切相关,原切顶参数无法满足顶板顺利垮落需求,需合理优化切顶参数;由此确定合理的切顶高度与角度分别为 9m与 15°,并提出了巷道顶板"锚杆索+钢筋网+梯形钢筋托梁"补强支护及两帮"锚杆+可缩U型钢+金属网+单体支柱"联合支护方法.通过现场实践,优化后的切顶参数裂缝率达 80%以上,沿空巷道围岩控制效果显著,保障了工作面安全高效回采.
In the process of mining,the dust produced is not only a major hazard source but also a serious threat to human health.In this paper,the water retention and wettability of five surfactants,SDBS,SAS,CAB-35,Twain-80,and CMC,were studied.According to the method of chemical dust removal,different surfactants were added to the aqueous solution to study the formulation of the dust removal a-gent.The results show that the surfactant monomer SDBS has good wetting characteristics on coal dust,and its wetting speed is faster when the concentration is very low.Different surfactants were mixed,and a water retention test and coal dust wettability test were also carried out on the new solution.SDBS+SAS was finally selected as the preferred compunction,with improved water retention and coal dust wettability,and the dust removal speed was fast.Finally,the effective and practical dust removal agent formula 0.25%SDBS+0.25%SAS with good dust removal effect,environmental protection,the low economic cost was obtained.
Based on the problem that the hard thick sandstone roof above the goaf is easy to accumulate a large amount of elastic ener-gy,which will cause rock burst when the roof structure is damaged,taking the No.7115 working face under No.3 Tianchen Coal Mine as the engineering background,the overburden movement law and mining stress distribution characteristics of the thick hard roof working face are studied through theoretical analysis and on-site monitoring.First of all,through theoretical calculation,it is obtained that the limit breaking step of thick conglomerate overlying the working face of No.3 coal seam on the elastic basis is about 43.5 m.Secondly,according to the analysis of on-site microseismic monitoring data,it is concluded that the breaking depth of the support pressure to the bottom plate is about 60 m,and the mining stress in the vertical direction is about 40 m above the coal seam and about 60 m below it.Finally,according to the monitoring data of borehole stress and drilling cuttings method,it is analyzed that the peak value of lateral abut-ment pressure is 8～9 m deep in the coal wall.The research results can provide an important guiding significance for the establishment of mine scour prevention technology system,and can also provide reference and help for the study of ground pressure in similar hard roof mines.
The key to the feasibility of high efficiency paste filling in goaf of fully mechanized mining face is filling hydraulic support,so it is very important to study the structure of filling hydraulic support.Based on the functional analysis of the filling hydraulic support in the goaf of fully mechanized mining face,the paper compares two schemes,the rotating tail beam structure filling hydraulic support and the telescopic tail beam structure filling hydraulic support,the latter has the advantages of large filling space,high support strength in the area to be filled,fast isolation speed and low isolation cost.
In order to reduce the threat of roof sandstone water to the mine safety production,taking each mine field in Taigemiao min-ing area as an example,combining with the results of special hydrogeological exploration,adopted the analytic hierarchy process,the geological structure,fracture characteristics,aquifer thickness,core recovery rate,water inflow per unit,permeability coefficient and flushing fluid consumption are deeply analyzed,the characteristics of pore and fissure development of sandstone in the roof of coal seam are studied and the water-rich zoning prediction is made.The results show that the development of pores and fissures in the sandstone of the coal seam roof is not uniform.The northwest of the exploration area and the south of Well-field system are the areas with pores and fissures,while the middle is relatively weak.The water-rich property in the middle of the exploration area of the first coal seam roof aquifer is strong,while the water-rich property in the periphery is weak.The water prevention and control measures are put for-ward,such as constructing underground drainage system,draining groundwater ahead of time,exploring and releasing water in mined-out area,opening and sealing bad borehole,and exploring hidden structure,etc.
针对目前采煤机传动系统运行维护缺少油液品质判据的问题,以MG200/500-WD型滚筒采煤机截割部的传动系统油液为研究对象,采用实验检测的方法完成了油液全生命周期内部品质的检测工作,结果表明,随着使用时间的延长,油液粘度逐渐增大.进一步参考工业闭式齿轮油液更换标准完成了油液6 个阶段的划分,采用电镜扫描的方法完成了不同阶段油液内部磨屑形态的检测,进一步规定了不同阶段对应的磨屑形态,指出了不同阶段油液中对应的磨屑粒径尺寸,用于采煤机传动系统现场维护和保养工作具有很好的指导意义.
