高产高效矿井开采模式的风险分析

首次尝试进行高产高效矿井开 风险分析,针对开采模式劣化的４种主要风险－资源工艺必 、工作面瓦斯浓度和煤层自然发火,建立了具体的风险估计的方法。采用模糊可能性理论量化开采模式劣化的可能性程度,并根据集值统计方法确定可能性分布函数。高产高效矿井开采模式的风险分析是对该领域研究,内容的拓展有助于从更广的角度和更深层次分析、评价高产高效矿井建设的合理性。     

易自燃特厚煤层综放面防(灭)火技术探析

义马煤业集团耿村煤矿13210综放面煤层厚度大,自然发火期短,开采期间井下多次发现浓烟,有时伴有明火.耿村煤矿冲击地压较大,使得顶板处煤体较为破碎,且使采空区漏风裂隙发育,漏风严重.13210综放面面临严峻的安全挑战.为避免综放面发火,实施了采空区注浆、注凝胶、上下隅角密闭封堵、进回风巷超前施工防火钻孔注浆防火、注水防火、下隅角埋管注氮、束管监测及温度检测系统等综合防(灭)火措施,有效遏制了采空区自然发火,改善了井下安全生产环境.     

孤岛工作面采空区煤炭氧化“三带”分布规律研究

张集煤矿17258工作面为孤岛工作面开采,为防止回采过程中出现自然发火事故,采用在上风巷埋设束管,利用JSG-7型煤矿束管监测系统采样、检测采空区内气体,测定出该面采空区“三带”变化规律,确保了17258工作面安全回采。     

综放面煤层自然发火区域划分的理论研究

应用煤炭自然发火理论,对综放面煤层自燃发生区域进行了全面分析,认为遗留在采空区内回采巷道周围的煤体容易自燃,即综放面采空区易形成自然发火的"U"型区域.根据通风渗流强弱情况,对采空区进行了重新划分,分别称之为强渗流带、弱渗流带和窒熄带.同时根据"U"型发火区和弱渗流带的交汇处能够发生高概率煤自燃的特点,提出了"易着火区"的新概念.在总结发火区域划分结果的基础上指出了综放面今后在防灭火技术措施的方向.     

基于多标度的矿井突水风险等级模糊综合评价

矿井突水是仅次于瓦斯突出的严重事故,是困扰煤矿生产和建设的突出问题.以事故致因理论和安全人-机-环境理论分析并构建了矿井突水风险评价指标体系,采用基于九标度的模糊层次分析法(FAHP)针对评价指标建立模糊判断矩阵、构建模糊一致矩阵并求取各指标的权重与综合权重,结合模糊综合评价法(FCE)进行了该评价指标体系的两级模糊综合评价.实例应用结果表明,基于多标度的矿井突水风险模糊综合评价模型能够对矿井突水风险进行数据挖掘,该评价结果可以为矿井突水防治提供理论参考和依据,亦可以为矿井其他类似的风险评价提供借鉴.     

易自燃煤层放顶煤开采工作面合理长度分析

以采空区自然发火危险为约束条件,用采空区场流方法(数值模拟)和自燃三带理论,结合实例,研究放顶煤开采工作面合理长度问题.得到工作面长度安全临界值与煤的最短自然发火期成正比关系.通过现场测定风量和采空区气体浓度分布,得到在当前工作面特定采空区流场环境下的自燃氧化带宽度和模型基础参数,数值模拟出不同工作面长度的采空区自燃氧化区宽度的变化关系;回归得到,在理论上,工作面长度与自燃氧化带宽度近似服从二次曲线关系.分析中给出了自燃安全判别量和自燃安全区间.     

地质条件定量分类系统在东滩煤矿中的应用

确定了定量评价矿井地质条件的指数,并利用模糊综合评判理论,综合各项指数对矿井地质条件进行了定量发类,该系统应用于东滩煤矿,提取了该矿的各项指数,综合得出了东滩煤矿的矿井地质条件分析结果,认为该矿地质构造中等、煤层稳定。     

突变理论在长江流域洪灾综合风险社会评价中的应用

从社会学的角度,分析了洪灾综合风险社会评估的基本组成.结合洪灾风险的自然属性和社会属性在短时间内发生转变的特性,应用突变评价理论,给出了考虑风险可接受水平的洪灾综合风险社会评估的突变评价方法,建立了长江流域的评价指标体系,并用实例验证了该模型方法的合理性与可行性.     

矿井闭坑的理论与技术框架

随着闭坑矿井的数量增多,其带来的安全与环境问题日益突出,且闭坑矿井的大量地下空间可以考虑利用.定义了矿井全生命周期的概念,明确了"矿井全生命周期采矿"的内涵.分析了闭坑矿井的数量、特征以及地下空间的特点.提出了矿井闭坑的工程背景、科学问题、关键技术、实践等基本问题框架.探讨了闭坑矿井的评价标准和责任体系、采空区覆岩长期沉陷规律、采空区水、气与污染物质的多场耦合与迁移规律、地下空间长期稳定性评价标准、地下空间利用方法等理论问题.在此基础上,分析了矿井闭坑的长期安全监测与评价、长期环境监测与评价、开拓巷道空间利用、采空区利用、生态环境修复等关键技术问题.政府与矿山企业需转变闭坑理念,重视闭坑矿井带来的安全、环境问题,从矿井全生命周期对该问题进行思考;积极探索闭坑矿井长期安全和环境监测、评价、修复治理技术,进行闭坑矿井的地下空间利用评价,并最大限度研究地下空间利用方法.     

矿井通风难易程度的准确划分及应用

针对采用等积孔法难以准确评价矿井(独立通风系统)通风难易程度的问题,以潘西煤矿通风系统为研究对象,提出一种矿井通风难易程度的分级与评判方法。该方法综合考虑矿井风量和等积孔2个指标,制定出通风困难线和通风容易线,把矿井通风系统划分为通风容易区、通风中等区和通风困难区,并建立了通风难易程度的评分模型,给出了评分方法与分级标准。实例分析表明,该方法能更准确地反映矿井通风系统存在的问题,并确定其改进的方向。     

综放面采空区温度场动态数学模化及应用

根据采空区浮煤氧化自燃过程的主要影响因素,建立了采空区温度分布的数学模型,计算分析了采空区浮煤温度分布随工作面推进速度的变化规律,确定了工作面的最小推进速度．并用ＦＯＲＴＲＡＮ语言编程,在微机上成功地模拟了忻州窑矿８９１６综放面采空区自然发火的动态变化情况     

综放面采空区遗煤自然发火过程动态数值模拟

通过对影响煤炭自燃因素的分析，建立了采空区内遗煤自燃过程数学模型，可随时预测不同漏风强度和不同推进速度的条件下，采空区遗煤自然发火的危险性．在计算机上对徐庄矿7235综放面采空区遗煤自燃过程中，氧化时间、工作面推进速度、遗煤厚度对煤温的影响进行了模拟，预报了在回采过程中采空区遗煤不自燃，而撤支架过程中确可能发生煤炭自燃，预报结果与实际相符。     

煤巷高冒区松散煤体自然发火的数值模拟研究

巷道高冒区自燃火灾，不仅严重影响到采掘工作面的安全生产，而且威胁到矿工们的生命安全．通过对煤巷高冒区特点和影响煤炭自燃因素的分析，根据多孔介质流体动力学、传热和传质理论，建立了高冒区松散煤体自然发火过程三维数学模型．以旗山煤矿高冒区为例，用有限元法进行了数值求解，得到高冒区渗流速度场、温度场和氧浓度场的分布，在此基础上划分出最易自然发火的区域，分析了高冒区自然发火的机理．结果表明：高冒区松散煤体漏风强度随孔隙率的增大而增加；高冒区松散煤体的中部区域存在最易自然发火区，是现场防治高冒区自然发火的重点区域．现场试验数据验证了数值模拟结果的合理性．     

Method for prevention and control of spontaneous combustion of coal seam and its application in mining field

Spontaneous combustion of coal seam has been and continues to be a big problem in coal mines. It could pose great threat to the safety of the whole mine and all miners, especially when it occurs in or nearby coal mines. Besides, environment of area surrounded mines during combustion can be threatened where large amount of toxic gases including CO_2, CO, SO_2 and H_2S can be leased by fire in mine. Hence, it is important and significant for scholars to study the controlling and preventing of the coal seam fire. In this paper, the complicated reasons for the occurrence and development of spontaneous combustion in coal seam are analysed and different models under various air leakage situations are built as well. Based on the model and approximately calculation, the difficulty of fire extinguishment in coal seam is pointed out as the difficulty and poor effect to remove the large amount of heat released. Detailed measurements about backfilling and case analyses are also provided on the basis of the recent ten years' practice of controlling spontaneous combustion in coal seams in China. A technical fire prevention and control method has been concluded as five steps including detection, prevention, sealing, injection and pressure adjustment. However, various backfill materials require different application and environmental factors, so in this paper, analyses and discussion about the effect and engineering application of prevention of spontaneous combustion are provided according to different backfilling technologies and methods. Once the aforementioned fire prevention can be widely applied and regulated in mines, green mining will be achievable concerning mine fire prevention and control.     

Effects of electrical resistance on the spontaneous combustion tendency of coal and the interaction matrix concept

There have been several developments in determining the spontaneous combustion liability of coal. Most of the methods of concern have purely been based on the internal properties of the coal itself. The relation between the crossing-point method and the electrical resistance of coal was examined here to outline the spontaneous combustion tendency of coal. The electrical resistance property of coal was looked into as a decision-making parameter of the interaction matrix concept for the final decision on the spontaneous combustion tendency.     

Influence of organic and inorganic properties of coal-shale on spontaneous combustion liability

Coal and coal-shale undergo low-temperature oxidation when exposed to air, potentially leading to spontaneous combustion. Coal-shale found in association with coal seams vary considerably in their intrinsic properties and spontaneous combustion liability index. Fourteen coal-shale samples collected from four different coal mines in Witbank Coalfield, South Africa, were experimentally investigated. The influence of coal-shale intrinsic properties and spontaneous combustion liability indices (determined by the Wits-Ehac Index and the Wits-CT Index) were established. The liability indices indicate relationships with the intrinsic factors and thus, identifying the major intrinsic factors affecting liability toward spontaneous combustion in these coal-shale samples. The XRF analysis indicated that the coal-shale samples are rich in SiO₂, Al₂O₃ and Fe₂O₃, while the XRD showed that same coal-shale samples are generally dominated with kaolinite and quartz. The coal-shale occurred in association with medium Rank C bituminous coal and contained varying proportion of macerals. The Wits-Ehac Index was unable to reliably determine liability indices of some coal-shale samples, and hence the Wits-CT Index was developed. The results obtained from the characterisation tests may be used as a tool to predict the spontaneous combustion liability in carbonaceous material and may serve as a reference when comparing coal-shale from different coal mines.     

基于活化能的煤自燃倾向性研究

对国内外主要煤自燃倾向性鉴定方法进行了分析和评价，指出了我国现行的煤自燃倾向性色谱吸氧鉴定法的不足之处，同时给出了煤自燃倾向性鉴定标准的基本原则．在煤自燃动力学基本方程基础上得到了煤绝热氧化方程，并设计了相应绝热氧化实验装置．通过理论和实验研宄，提出了能够反应煤自燃关键阶段，即低温氧化阶段动力学参数活化能E作为煤自燃倾向性鉴定指标，并测试了3个典型煤样的低温氧化活化能E．最后，通过现场煤自燃发火期与煤物理吸附氧量和低温氧化活化能E的对比，对该指标的实用性和科学性进行了检验．     

Prediction of oxygen concentration and temperature distribution in loose coal based on BP neural network

An effective method for preventing spontaneous combustion of coal stockpiles on the ground is to control the air-flow in loose coal. In order to determine and predict accurately oxygen concentrations and temperatures within coal stockpiles, it is vital to obtain information of self-heating conditions and tendencies of spontaneous coal combustion. For laboratory conditions, we de-signed our own experimental equipment composed of a control-heating system, a coal column and an oxygen concentration and temperature monitoring system, for simulation of spontaneous combustion of block coal (13-25 ram) covered with fine coal (0-3 mm). A BP artificial neural network (ANN) with 150 training samples was gradually established over the course of our experiment. Heating time, relative position of measuring points, the ratio of fine coal thickness, artificial density, voidage and activation energy were selected as input variables and oxygen concentration and temperature of coal column as output variables. Then our trained network was applied to predict the trend on the untried experimental data. The results show that the oxygen concentration in the coal column could be reduced below the minimum still able to induce spontaneous combustion of coal-6% by covering the coal pile with fine coal, which would meet the requirement to prevent spontaneous combustion of coal stockpiles. Based on the predic-tion of this ANN, the average errors of oxygen concentration and temperature were respectively 0.5% and 7 ~C, which meet actual tolerances. The implementation of the method would provide a practical guide in understanding the course of self-heating and spontaneous combustion of coal stockpiles.     

Spontaneous combustion of coals and coal-shales

Spontaneous combustion of coal is a well-known phenomena around the globe. Apart from the coal itself,burning coal-shales is becoming a problem in the South African coal mines. Serious incidents of spontaneous combustion have been reported as a result of self-heating of reactive coal-shales. The intrinsic properties and spontaneous combustion tests of 28 selected coal and coal-shale samples were conducted and a relationship between the two has been established. Intrinsic properties were obtained by using the proximate and ultimate analysis, and spontaneous combustion liability tests results were obtained by using the Wits-Ehac and Wits-CT indices. The experimental results show that intrinsic properties of these materials complement to the spontaneous combustion liability tests results. Comparative analyses of intrinsic properties and spontaneous combustion characteristics indicate similarities between the mechanism of coal oxidation and that of the oxidative processes undergone by coal-shales. For the tested samples, coal samples have a higher intrinsic spontaneous combustion reactivity rating than the coal-shales.Furthermore, an increase in carbon, moisture, hydrogen, volatile matter, nitrogen and a decrease in ash content indicate an increased proneness to self-heating. The concentration of pyrite found in the coal-shales accelerates self-heating. The event of spontaneous combustion can occur if coal-shales absorb sufficient oxygen when subjected to atmospheric conditions.     

A review of research on spontaneous combustion of coal

Coal oxidation at low temperatures is the heat source liable for the self-heating and spontaneous combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this phenomenon by previous researchers have provided significant progress. It is wellknown that coal oxidation at low temperatures involves oxygen consumption and formation of gaseous and solid oxidation products. This process is majorly influenced by temperature, oxidation history of coal,coal properties, particle size distribution of the coal, etc. The current understanding of the phenomenon of self-heating and spontaneous combustion of coal is discussed along with the different experimental and numerical models established to predict self-heating characteristics of coal. This paper focuses on the global position of the study carried out by academics, research institutes and industries on spontaneous combustion of coal and coal mine fires. Within this framework, the generally used spontaneous combustion techniques to predict the spontaneous combustion liability of coal were evaluated. These techniques are well-known in their usage, but no specific method has become a standard to predict the spontaneous combustion liability. Further study is still needed to indicate a number of impending issues and to obtain a more complete understanding on the phenomenon.