Roof filling control technology and application to mine roadway damage in small pit goaf

To recover coal resources that have been damaged by traditional mining methods and ensure stability of the lower roadway in a small pit goaf,the goaf area must be filled and reinforced.In this research,the 1202 working face of the Hanzui mine is considered as an example for classifying the roof of the mining tunnel under the small kiln destruction zone,the effect of the goaf on the roadway is determined based on the radio tunnel penetration method,a mechanical model to determine the roof filling control mechanism was established,and the duct foaming system and roof filling process were designed.The results show that the scope and degree of influence of the goaf on the mining lane are large,but safe tunneling can be ensured through the use of a steel shed and advanced grouting techniques.When the roof conditions are not similar,materials with different filling heights and filling strengths can be used to control the roof filling of the roadway.By combining field experience and laboratory tests,it was determined that a high-foaming material with a water-cement ratio of 1:0.6,a suitable high-foaming additive,and a water volume ratio of 1:30 is cost-efficient for filling and meets the filling strength requirements.Finally,the reliability of the proposed technology was verified by field experiments,which provide a reference for filling operations in similar mines.

Optimization of clay material mixture ratio and filling process in gypsum mine goaf

Because there is neither waste rock nor mill tailings in the gypsum mine, and the buildings on the goaf of gypsum mine are needed to be protected, the research proposed the scheme of the clay filling technology. Gypsum, cement, lime and water glass were used as adhesive, and the strength of different material ratios were investigated in this study. The influence factors of clay strength were obtained in the order of cement, gypsum, water glass and lime. The results show that the cement content is the determinant influence factor, and gypsum has positive effects, while the water glass can enhance both clay strength and the fluidity of the filing slurry. Furthermore, combining chaotic optimization method with neural network, the optimal ratio of composite cementing agent was obtained. The results show that the optimal ratio of water glass, cement, lime and clay (in quality) is 1.17:6.74:4.17:87.92 in the process of bottom self-flow filling, while the optimal ratio is 1.78:9.58:4.71:83.93 for roof-contacted filling. A novel filling process to fill in gypsum mine goaf with clay is established. The engineering practice shows that the filling cost is low, thus, notable economic benefit is achieved.

DIMINE填挖方量计算原理与方法研究

填挖方量计算是土石方工程的重要环节之一。为了正确应用填挖方量计算方法,提高计算精度,分别研究了DIMINE软件中4种不同计算方法的基本原理。结合不同的工程案例,以相应的布尔体积为标准,对4种方法的计算结果进行对比分析,探讨了各种计算方法存在误差的原因,以及对不同数据特征的适应性。研究结果表明,由于原始数据的地貌特征、地形变化趋势及坡度变化的影响,不同方法的计算精度不同。根据每种计算方法的基本原理和实验结果的误差分析,针对在不同数据特征条件下填挖方量计算方法的应用问题,提出了相应的建议,为正确使用DIMINE软件进行填挖方量计算提供参考。

Raw Gangue Filling Mining under Construction —A Case Study in China

In order to recover the strip pillar coal resources, reduce the amount of gangue mountain and realize remediation of the goaf environment in the old mining area, the raw gangue filling mining technology was proposed. According to the previous practical experience, the feasibility of the implementation of raw gangue filling mining technology in the coal-pressed area was analyzed. Through the filling gangue compaction test, the deformation under different loading stages was obtained. Further, a reasonable prediction of the deformation beyond the experimental limited loading load was made based on the experimental results. Through the deformation source analysis of the whole process of gangue filling, the key factors for controlling deformation before, during, and after filling were determined. Additionally, the proportion of deformation during different stages was quantified. Considering the protection of surface buildings, mining fullness of the working face and mining technology, the production parameters of 1209 and 1210 filling working faces were preliminarily determined. Through numerical simulation, the rationality of mining scheme was verified. Based on the practice of 1209 working face and the key factors to control the deformation of gangue filling, the mining system and process in 1210 working face were optimized. According to the measured surface rock movement, raw gangue filling mining technology can meet the requirements of surface building protection level. Especially, this paper provides a method to quantitatively calculate the equivalent mining height (EMH) of raw gangue filling and its mining deformation, which has reference significance for old mining areas.

煤矸石井下原位智能分选充填技术研究进展

传统井下煤矸石需运输至地面处理,不仅占用地面国土空间、自燃或雨水淋滤造成大气与环境污染,而且长距离无效运输造成的能源消耗问题已成为制约煤矿低碳发展的关键瓶颈。为实现煤矿矸石不出井,从煤炭生产源头减少碳排放与单位产出能源资源消耗,实现煤炭的绿色低碳智能开采,回顾了煤矸石井下分选充填技术现状及智能化进展,并在此基础上展望煤矸石井下分选充填技术发展趋势,提出了煤矸石井下原位绿色智能分选、充填新方法,详细阐述了煤矸智能分选机及新型充填液压支架的结构及原理,以最大化缩短矸石无效运输距离。为处理采煤工作面矸石,预防煤岩动力灾害,提出了包含少矸化智能开采系统、原位智能分选系统、工作面矿压反演系统、精准科学充填系统四大子系统的煤矿井下采选充智能一体化系统,并探讨了各子系统间的新环逻辑关系,以形成采煤利于分选、分选利于充填、充填利于采煤的良性循环。为处理掘进工作面矸石,提出了包含智能快掘系统、智能分选系统、煤矸分运系统、智能充填系统四大子系统的煤矿井下掘选充智能一体化系统,并对各子系统所负责工作及智能化实现进行了阐述。所提出的新工艺有望实现煤矿矸石不出井,并为煤矸石原位智能分选充填方法及采选充一体化系统的研究提供新思路。

An analytical solution for evaluating the safety of an exposed face in a paste backfill stope incorporating the arching phenomenon

In current underground mining, the stability of the exposed backfill face is a basic issue associated with mining design and has been the subject of considerable research in mining safety and efficiency. In this study, an improved analytical solution for evaluating the safety of vertically exposed faces in backfilling was proposed. Based on a differential slice method, the proposed solution emphasizes the arching effect as having the advantages of more rigor and wider scalability. Feasibility of the proposed solution was validated with classic centrifuge results. Good agreement between compared results indicated that the proposed solution skillfully predicts the behavior of the paste centrifuge model. Additionally, calculation of exposed face safety in sequential filling was presented. The proposed solution has practical significance in mine backfill design.

DIMINE软件在矿山道路设计中的应用

露天矿山的道路设计工作是确保矿山生产高效、稳定的重要环节^([6])。文中以德兴铜矿为例,运用DIMINE软件对该矿富家坞采区运岩公路进行设计,并分析探讨该软件在道路设计中的应用效果。结果表明:DIMINE软件在矿山道路设计工作中与传统CAD道路设计方法相比具有明显的优势。DIMINE软件优化了道路设计过程中的制图程序,解决了道路设计工作中填挖方量快速计算的问题,有效提高了道路设计工作的效率和准确性。

Research on Deformation Regularity of Surface Migrating With Waste-fill Mining

Using FLAC3D numerical simulation software,the influence laws that the different mining depth,mining width and filling step have on the surface subsidence and horizontal movement under the condition of filling mining has been studied.The functional relation among full subsidence and horizontal movement of surface,mining depth,mining width and filling step has been given,which provides theoretical formulas been referenced for filling mining theory and has a certain guiding value.

端帮充填开采支撑煤柱参数设计方法

合理地设计端帮充填开采下支撑煤柱参数是端帮开采工艺推广应用的前提。对端帮充填开采前后煤柱受力变化进行了分析,阐明了充填体提高煤柱强度的机理。根据有效区域理论计算了煤柱上方载荷,推导了基于土压力公式的煤柱侧向约束力,结合CIMFR煤柱强度经验公式和Mohr-Coulomb强度准则获得了充填条件下煤柱强度,提出了兼顾煤柱安全系数的非均布载荷下端帮充填开采支撑煤柱参数设计方法。基于端帮充填开采支撑煤柱参数计算方法,考虑端帮充填开采三角载荷作用,提出了对采硐分段充填的方法,并且给出了不同条块充填高度的计算方法。考虑充填环节与端帮采煤时间的协调性,在一步式开采不合理的情况下,设计了两步式充填开采顺序、三步式充填开采顺序。以某露天矿为工程背景,设计了端帮充填开采支撑煤柱参数,较非充填开采单个煤柱宽度减小3.5 m,资源回收率由33.7%提升至68.4%,在分段充填条件下,单个采硐充填材料用量减少2053.6 m^(3)。提出了端帮充填开采条件下支撑煤柱设计方法,对推动露天煤矿端帮充填开采具有科学意义。

金属矿山高浓度充填管道磨损规律与防控技术

金属矿高浓度充填能有效消除尾矿库和采空区危害,但充填管道磨损问题也成为制约充填效率的因素之一。基于对管道磨损类型的划分,从颗粒性质、料浆性质、料浆—管壁接触条件、管材性质和管道所处外部环境5个方面综述了充填管道磨损的影响因素;基于理论分析和现场实测归纳了5种不同形式充填管道的磨损规律,以此总结了充填管道磨损的防控技术。现有研究结果表明,不满管流时,充填管道最主要的磨损形式是冲蚀磨损,料浆流速的影响最显著;满管流时,磨蚀和腐蚀对管道磨损起重要作用,料浆浓度的影响最显著。垂直管道中,料浆—空气交界面处磨损最严重,提高满管率并采用等倍线设计可有效控制其磨损。水平直管和倾斜直管底部磨损最严重,水平弯管的底部和垂直弯管外侧为易磨部位。使用新型管道结构和耐磨管材,提高料浆均质性,优化充填骨料级配,改进充填作业制度,全面监测管网压力,革新管道磨损数据获取手段,采用数值模拟技术深入揭示管道磨损规律等措施,可直接或间接对充填管道磨损防控起到积极作用。研究结果可为矿山充填管道磨损控制提供指导。

煤岩体突水通道骨料灌注运移堆积机制试验

为揭示突水通道中骨料运移堆积的演化规律,开展了动水条件下骨料灌注试验,得到了骨料的初始沉积位置、堆积体形成方向以及堆积体极限堆积高度与水流速、骨料灌注速度等影响因素的内在关联。结果表明:在1.0 m/s高流速动水环境中,骨料堆积体形成方向为先逆水流方向生长至投料孔底后转为顺水流方向生长;在0.3 m/s低流速条件下,采用口径36 mm漏斗投料同口径18 mm相比,骨料灌注总量相同时,其堆积体的极限高度提升了41%。基于数值力学模型——计算流体动力学-离散元方法(computational fluid dynamics and distinct element method,CFD-DEM),研究了骨料灌注期间突水通道内流场的时空分布特征以及骨料堆积体的过水阻力作用对突水通道内静水压力的影响机制。

煤矿矿区普适性拓展型固体改性充填采煤技术与装备

从我国煤炭行业绿色发展趋势和要求出发,分析了煤炭企业对不同充填开采方式选择的考量因素,以及影响充填开采技术推广的制约因素,针对不同矿区地域分布特征和充填需求差异性,划分了煤矿充填开采“保护生态环境优先、保护地面建筑优先、处理煤矸固废优先、提高经济效益优先”4类优先原则,提出了“以充填开采作为煤矿保护生态环境的调节工具,建设全过程全息立体生态矿山”的生态开采目标。依据充填开采顶板限定变形力学模型,阐述了影响充填开采目标岩层下沉量的构成因素,构建了生态环境保护、地面建筑保护、矸石固废处置3种充填工程模式下的工作面支护强度计算及覆岩变形控制方程。介绍了我国煤矿普适性充填采煤技术发展现状及发展方向,涵盖散状原矸固体充填、类贫混凝改性充填、矸石混凝土充填、薄煤层充填、区域性保护充填、巷道充填、选充留协同等适应各类煤矿需求的充填采煤技术,详细描述了不同充填技术的材料制备、运输、充填工艺特点及适应性充填装备。为实现煤矿充填智能化,建立了全面的数据感知系统,通过空间规划及充填效果判定来实现从单元到整体充填工作面的智能化过程,结合传感器网络和人工智能算法,实时监测和控制煤矿固体充填过程,提高充填质量和充填效率。煤矿充填开采在我国绿色矿山建设的远景规划中将扮演更加重要的角色,加强基于主动充填的煤矿生产全过程生态矿山建设、普适性充填技术工艺体系构建、新型固体充填材料研制、智能化充填开采研发等4个方向的科技攻关,我国煤矿充填开采会有极为广阔的发展前景。

夯实矸石压缩-固结蠕变成岩过程及等价采高模型分析

目的为了研究被夯实矸石压缩-固结蠕变成岩过程及其等价采高模型,方法以亭南煤业公司1102矸石充填工作面为工程背景,采用理论分析、数值模拟、室内试验、现场实测等方法进行研究。结果结果表明:矸石充填工作面最大控顶距=端面距+截割深度+顶梁长度+架后触矸距离;顶板回转下沉量等于最大控顶距乘以支架后倾角度正弦值;架后可充填空间高度等于采高减去顶板回转下沉量、欠接顶量、架后底鼓量。被夯实矸石在可充填空间内压缩-固结蠕变成岩的4个阶段及可充压缩率分别为骨架调整段(7.42%),缓慢压缩段(5.39%),固结沉降段(0.34%),蠕变成岩段(12.38%)。由该等价采高模型可知,1102工作面4阶段等价采高为骨架调整段0.94 m,缓慢压缩段1.10 m,固结沉降段1.11 m,蠕变成岩段1.48 m。结论通过概率积分法预测、数值模拟和沉陷观测对比可知,1102工作面走向和倾向主断面地表下沉曲线均为碗形。前两阶段地表下沉曲线平缓,后两阶段地表下沉曲线陡峭。

煤矿充水因素评价及涌水量预测

含水层、老窖水以及采空区积水等水源对煤矿安全生产带来威胁。以山西省某煤矿为例,分析充水因素,并对采用富水系数比拟法对涌水量进行预测,有利于煤矿防治水工作开展,对井下安全生产具有重要意义。

基于满管输送的充填管路优化研究

满管输送可以延长充填管路的使用寿命,提高矿山充填作业效率。基于凡口铅锌矿新探明边缘矿体开采的充填需求,针对现有充填管线直径100 mm无法实现满管输送的问题,以地表管线SL1和地下管线L2-2为研究对象,开展充填管路优化研究。首先,运用理论计算,得出输送分级尾砂和细尾砂时,SL1的满管率分别为0.62和1.95,L2-2的满管率分别为0.72和2.26;其次,以最优满管率0.8为标准,通过公式推导,得出输送分级尾砂和细尾砂时SL1的理想水平管径分别为87 mm和155 mm,L2-2的理想水平管径分别为94 mm和168 mm;最后,利用CFD构建管道模型,运用Fluent软件进行变径满管流的数值模拟,通过对管道的压力及出口最大流速等进行对比分析得出,输送分级尾砂时减小管径可以增大满管率,且仍可自流输送;输送细尾砂时增大管径可以降低泵送压力。模拟结果证明此优化方案合理且具有很强的可行性。

综放架后膏体充填空间实测与顶煤冒放性影响规律研究

针对综合机械化放顶煤开采中的矸石处置问题,提出了一种放顶煤架后膏体充填方法,设计了柳巷煤矿综放工作面采空区空洞现场监测方案,定性分析了5个方面对顶煤冒放性的影响,采用PFC^(2D)数值模拟方法,定量分析了充填高度对顶煤冒放性的影响。研究结果表明:倾向方向上工作面上部端头附近采空区空洞体积最大,走向方向上工作面刚推进到新位置时采空区空洞体积最大,支架顶梁后方空洞体积大于支架尾梁上方;充填高度从0增加至3 m时,顶煤放出率由92.56%降低至86.11%,降低了6.45个百分点,顶煤含矸率由13.94%降低至13.17%,降低了0.77个百分点,相比于顶煤含矸率,充填高度对顶煤放出率影响较大。研究可为类似地质条件综放架后膏体充填开采实现提供理论基础。

内蒙古母杜柴登煤矿3^(-1)煤充水条件及矿井涌水量预测

母杜柴登煤矿矿井涌水量大,且属于高矿化度水,面临着大量疏排矿井涌水和矿井水地面处理的压力。在分析矿区地质及水文地质条件的基础上,认为开采3^(-1)煤层时,矿井水来源于3^(-1)煤顶板─直罗组底界砂岩含水层,包括直罗组底部中、粗粒砂岩含水层和3^(-1)煤顶板延安组三段砂岩含水层。运用大井法和达西定律计算的30209工作面涌水量分别为931m^(3)/h、919m^(3)/h,与实际接近。研究可为工作面侧向注浆封堵(含水层改造)、帷幕截流减量的可行性和减量程度提供依据。

煤矿覆岩离层注浆减沉技术研究及应用

针对门克庆煤矿11-3101工作面铁路下压煤问题,为提高煤炭资源回收率,应用离层注浆减沉技术减小地表下沉,通过室内试验测试了不同配比充填料浆的流变特性,确定了合适的料浆配比,同时构建采动覆岩离层演变力学模型,提出了离层动态发育位置及离层开度预测方法。研究结果表明:11-3101工作面从下往上将会产生四个离层,分别位于工作面顶板上方45.42、228.38、337.19、363.99 m处;离层开度从下到上依次为2.62、1.49、1.39和1.33 m,开度随着层高的增长而递减;注浆压力为6.5 MPa,注采比大于45%时,地表倾斜变形值小于3 mm/m,现场监测结果显示铁路路基最大沉降量仅58.72 mm,注浆减沉效果显著。

生态脆弱煤矿区水体中微生物群落特征及矿井充水指示

我国生态脆弱矿区水资源整体匮乏,但局部地区矿井涌水却异常巨大。对生态脆弱矿区异常矿井充水水源识别,对矿区生态环境保护意义重大。研究以涌水量超过1 000 m^(3)/h的榆树湾煤矿为背景,在分析矿井涌水量特征的基础上,采集了研究区主要含水层和矿井涌水点的30个水样,开展了水样高通量微生物测序研究。对测序结果采用Alpha多样性分析、Beta多样性分析及微生物构成差异分析,系统研究了矿井水体中微生物群落特征,分析了矿井充水来源。研究结果表明:高通量测试结果通过了Coverage指数检验,验证了其用于矿井充水识别的可行性。但人类活动密切接触的水样显示出微生物更加丰富,需要在取样中有效规避。榆树湾煤矿浅表松散含水层中微生物丰富度和多样性都较高,以新鞘脂菌属(Novosphingobium)、梭杆菌属(Fusobacterium)和硫属(Sulfuricum)等微生物丰度最高;直罗组为代表的基岩含水层微生物丰富度较低,但微生物多样性较高,以丛毛单胞菌属(Comamonas)、蛲虫属(Vermiphilaceae)和巴氏杆菌(Paeniglutamicibacter)等微生物丰度最高。所有水样中最为优势的门类为变形菌门,占比达到35.5%~89.7%。Alpha多样性、PCoA和NSDM分析揭示了榆树湾矿井充水水源主要来自松散含水层和直罗组含水层。但Beta多样性分析发现,随着直罗组静储量的释放,松散层中离石组黄土充水比例进一步增大。综合分析显示,榆树湾煤矿目前为基岩含水层快速释水+离石组含水层持续释水模式的充水模式,矿井涌水统计分析结果验证了这一结论。研究为相似化学成分含水层充水识别,提供了新的方法。

多断层复杂地质条件下条带充填开采工艺研究

为优化沙梁煤矿多断层复杂地质条件下的开采布局,提高煤层采出率,提出在矿井一水平多断层切割区域布置短壁或异形条带充填开采工作面,通过多轮循环充填开采置换煤柱。研究表明:试验C135206工作面基载比J_(Z)<0.8、基采比J_(C)<9,条带采宽处于直接顶板破断判据确定的极限跨距范围,工作面采用基于连采机掘采的“采6.6 m、留19.8 m”四轮顺序采充的三倍基准参数是适宜的;工作面条带巷道顶部敷设多通道导气管与注浆管的接顶方式可保证充填体充分接顶,砌块档墙有助于条带巷道两端墙体稳定性。研究为煤矿优化开采布局、提升矿井采出率提供了一条崭新思路。