矿井采矿技术与施工安全应用

在矿井采矿技术水平不断提升的背景下,采矿安全要求随之提高,在应用矿产采矿技术的时候,不但需要在技术优势支持下保证采矿的科学性,而且应该通过加强安全管理尽量减少采矿过程中出现的风险问题,从而确保采矿人员的生命安全不会受到威胁。因此煤矿企业应当提前分析采矿场地的基本情况,按需选用合适的采矿技术,在采矿现场落实好施工安全措施,保证能够为采矿工作、矿产生产工作提供安全指导意见,方可在保证采矿施工安全的基础上进一步提高采矿作业效率。本文首先分析常用的矿井采矿技术,其次探讨矿井工程采矿施工安全要点,以期对相关研究产生一定的参考价值。

高产高效矿井采矿设备在后寿命期的问题与对策研究

由于我国社会经济的飞速发展,对矿产资源的需求量持续增加。随着采矿技术的不断进步,高产高效的采矿技术必然会变成主流采矿方法,而高产高效的采矿工艺依赖高效的采矿设备。现以神东集团为例,对高产高效矿井采矿设备在后寿命期的问题和对策进行研究,力求为今后的相关工作提供可靠的参照。

高产高效矿井采矿设备在后寿命期的问题与对策研究

通过对矿井采矿设备后寿命含义进行概述,进一步对高产高效矿井中存在问题展开分析,根据存在的问题提出一些解决对策,为推动煤矿企业高产高效矿井地建设打下坚实基础,为今后的相关工作提供可靠的参考。

浅论采矿矿井通风节能技术的运用

运用采矿矿井通风节能技术,需要体现综合治理,既要维修、维护或更新通风设备,又要排除影响通风效果的各种因素,处理好矿井漏风问题、风阻问题、构筑物建设问题和自然风压利用问题,用以提高地下矿井巷道通风效率和质量。

采矿安全管理与事故防范策略分析

目前随着我国矿产机械化程度不断提升,矿产使用的采矿设备也变得更加复杂,电气技术不断发展,也给矿井采矿设备带来一定的提升,因为矿井的生产条件以及生产环节都较为复杂,因此设备的使用范围比较大,使用面也比较广。持续的改进矿井采矿安全管理水准,是能够让矿井采矿安全生产以及获得经济效益提升的根本性保障,基于此,本文主要讨论了采矿安全管理与事故防范的策略。

矿井通风设计的智能化研究

虽然我国采矿矿井比较多,但是整体采矿技术水平比较低,而矿井通风系统是矿井的八大系统之一,有着极其高的地位和作用。然后,矿井通风系统又与其它系统有所不同,该系统既看不到也摸不着,想要形成一个系统化、整体化的模型是十分困难的,因此,在实际的矿井采矿过程中很难全面地控制和把握通风系统的设计与管理。随着高新技术的不断发展,智能化的理念深深地渗透到矿井通风系统的设计中,这将能够全方位的、自动的监视矿井下的通风状况,便于技术人员及时地调整采矿工作方案,并保证采矿人员的生命安全。本文简要介绍了矿井通风系统,并提出了矿井通风设计的智能化研究,希望能给读者一些帮助。

矿井开采工程安全管理与事故防范措施探讨

随着我国经济的发展和社会的进步,对于矿产领域来说也得到了一定的发展,但是仍然存在一系列的问题。从目前的发展形势来看,可以得出对于大部分的矿产企业来说,从而忽视了安全管理工作以及对于事故的防范工作,导致矿井采矿生产工作中事故多发。本文主要针对于矿井采矿安全管理以及事故的预防展开一系列的讨论并且提出合理化的建议,希望对我国矿井开采工程工作的安全有一定的保障。

浅谈矿井通风节能方法

我国井下采矿矿井通风系统中十分常见的问题是消耗能源的总量比较大,但是工作效率也始终比较低,严重影响到采矿单位的经济效益。因此,在矿井生产过程中,一定要保证每一个用风工作均能得到充分的风量供给。采矿单位需要在不断地发现矿井通风系统中存在的问题,并寻求科学合理的手段将其不断地改进和完善,以降低通风系统的能耗,提高工作效率,满足当今社会追求的环保、节能、低碳的生产目标。文章简要分析了我国矿井通风系统中影响通风阻力的因素,并提出了一些可供参考的矿井通风节能方法,希望能给读者一些帮助。

Application of HEMS cooling technology in deep mine heat hazard control

This paper mainly deals with the present situation, characteristics, and countermeasures of cooling in deep mines.Given existing problems in coal mines, a HEMS cooling technology is proposed and has been successfully applied in some mines.Because of long-term exploitation, shallow buried coal seams have become exhausted and most coal mines have had to exploit deep buried coal seams.With the increase in mining depth, the temperature of the surrounding rock also increases, resulting in ever increasing risks of heat hazard during mining operations.At present, coal mines in China can be divided into three groups, i.e., normal temperature mines, middle-to-high temperature mines and high temperature mines, based on our investigation into high temperature coal mines in four provinces and on in-situ studies of several typical mines.The principle of HEMS is to extract cold energy from mine water inrush.Based on the characteristics of strata temperature field and on differences in the amounts of mine water inrush in the Xuzhou mining area, we proposed three models for controlling heat hazard in deep mines:1) the Jiahe model with a moderate source of cold energy;2) the Sanhejian model with a shortage of source of cold energy and a geothermal anomaly and 3) the Zhangshuanglou model with plenty of source of cold energy.The cooling process of HEMS applied in deep coal mine are as follows:1) extract cold energy from mine water inrush to cool working faces;2) use the heat extracted by HEMS to supply heat to buildings and bath water to replace the use of a boiler, a useful energy saving and environmental protection measure.HEMS has been applied in the Jiahe and Sanhejian coal mines in Xuzhou, which enabled the temperature and humidity at the working faces to be well controlled.

Coal bursts in the deep longwall mines of the United States

Coal bursts involve the sudden, violent ejection of coal or rock into the mine workings. They are a particular hazard because they typically occur without warning. During the past 2 years three US coal miners were killed in two coal bursts, following a 6-year period during which there were zero burst fatalities. This paper puts the US experience in the context of worldwide research into coal bursts. It focuses on two major longwall mining coalfields which have struggled with bursts for decades. The Utah experience displays many of the ＂classic＂ burst characteristics, including deep cover, strong roof and floor rock, and a direct association between bursts and mining activity. In Colorado, the longwalls of the North Fork Valley （NFV） also work at great depth, but their roof and floor strengths are moderate, and most bursts have occurred during entry development or in headgates, bleeders, or other outby locations. The NFV bursts also are more likely to be associated with geologic structures and large magnitude seismic events. The paper provides a detailed case history to illustrate the experience in each of these coalfields. The paper closes with a brief discussion of how US longwalls have managed the burst risk.

Simulation of Water-Resistance of a Clay Layer During Mining:Analysis of a Safe Water Head

Given previous research and prototypical geological conditions of a mining workface,we simulated fis-sure development in clay layers at the bottom of Quaternary strata and above bedrock,sand and water inrush during mining by model experiments. The results show that V-shaped fissures usually occur in the bottom clay layer at the front top of the active face and that the position of these fissures changes periodically with ground pressure intervals. These fissures occur exactly in the area where the horizontal strain is concentrated. The results also demonstrate that the permeability coefficient of the cracked clay decreases while fissures tend to close. The permeability of the cracked bottom clay layer increases rapidly after a turning point in the permeability coefficient-water head curve (K-H curve) under a certain vertical load. Under static water pressure,the permeability coefficient of cracked clay decreases when load increases. A turning point in the K-H curve showed up and can be seen as a cutoff point to de-cide water inrush under a certain load level. Under an instantaneous water head,the greatest ability of the cracked clay to avoid drastic water inflow is a little higher than that under static conditions.

RC beam strengthened with pre-stressed CFP under the secondary load

Feasibility of using pre-stressed carbon fiber plates to strengthen reinforced concrete beams was studied. Based on the characteristics of carbon fiber plates, we developed a pre-stress clamp and a device for applying the pre-stress. Contrast tests were conducted between ordinary carbon fiber plates and a pre-stressed carbon fiber plate and between secondary loaded carbon fiber plates and a concrete beam strengthened with a secondary loaded carbon fiber plate. On this basis, we analyzed the failure pattern, the width of cracks and their distribution, the cracking load, the yield load, the limit load and the relation between load and deflec- tion. The results indicate that using pre-stressed carbon fiber plates to strengthen concrete beams is feasible and effective.

Characteristics of Gas Emission at Super-Length Fully-Mechanized Top Coal Caving Face

Characteristics of gas emission at the K8206 working face in the Third mine of the Yangquan Coal Group were investigated. The effects of strata movement,advancing velocity of working face,production capacity of working face and gas extraction capability of strike high-level entry on gas emission at K8206 working face were analyzed. A regression equation,reflecting the relationship between relative gas emission rate and the production capacity of work-ing faces,was established. Another regression equation showing the relationship between the gas emission rate from adjacent layers when the working face was advancing for one metre and advancing velocity was derived. It can be con-cluded that,1) the amount of gas emitted at the K8206 working face is far greater than that of ordinary top coal caving faces with a dip length of 180-190 m; 2) the dynamic process of gas emission from adjacent layers during the initial mining stage is controlled by the movement of key strata; 3) the amount of gas emitted that needs to be forced out by air is greatly affected by the capability of gas extraction; 4) when the advancing velocity is between 3.5-5.5 m/d or when the output is up to 8-12 kt/d,the gas emission from adjacent layers is almost constant.

Integration of real options into short-term mine planning and production scheduling

Commodity prices have fallen sharply due to the global financial crisis. This has adversely affected the viability of some mining projects, including leading to the possibility of bankruptcy for some companies. These price falls reflect uncertainties and risks associated with mining projects. In recent years, much work has been published related to the application of real options pricing theory to value life-of-mine plans in response to long term financial uncertainty and risk. However, there are uncertainties and risks associated with medium/short-term mining operations. Real options theory can also be applied to tactical decisions involving uncertainties and risks. This paper will investigate the application of real options in the mining industry and present a methodology developed at University of Queensland, Australia, for integrating real options into medium/short-term mine planning and production scheduling. A case study will demonstrate the validity and usefulness of the methodology and techniques developed.

Exploitation technology of pressure relief coalbed methane in vertical surface wells in the Huainan coal mining area

Exploitation technology of pressure relief coalbed methane in vertical surface wells is a new method for exploration of gas and coalbed methane exploitation in mining areas with high concentrations of gas, where tectonic coal developed. Studies on vertical surface well technology in the Huainan Coal Mining area play a role in demonstration in the use of clean, new energy resources, preventing and reducing coal mine gas accidents and protecting the environment. Based on the practice of gas drainage engineering of pressure relief coalbed methane in vertical surface wells and combined with relative geological and exploration en- gineering theories, the design principles of design and structure of wells of pressure relief coalbed methane in vertical surface wells are studied. The effects of extraction and their causes are discussed and the impact of geological conditions on gas production of the vertical surface wells are analyzed. The results indicate that in mining areas with high concentrations of gas, where tectonic coal developed, a success rate of pressure relief coalbed methane in surface vertical well is high and single well production usually great. But deformation due to coal exploitation could damage boreholes and cause breaks in the connection between aquifers and bore-holes, which could induce a decrease, even a complete halt in gas production of a single well. The design of well site location and wellbore configuration are the key for technology. The development of the geological conditions for coalbed methane have a significant effect on gas production of coalbed methane wells.

Mining a coal seam below a heating goaf with a force auxiliary ventilation system at Longhua underground coal mine, China

Extraction of a coal seam which lies not far below a heating goafcan be a major safety challenge. A force auxiliary ventilation system was adopted as a control method in successful extraction and recovery of the panel 30110 of the #3-1 coal seam, which is about 30-40 rn below the heating goaf of the #2-2 seam at Longhua underground coal mine, Shanxi Province, China. Booster fans and ventilation control devices such as doors and regulators were used in the system. The results show that, provided that a force auxiliary ventilation system is properly designed to achieve a pressure balance between a panel and its overlying goat＇, the system can be used to extract a coal seam overlain by a heating goal. This paper describes the design, installation and performance of the ventilation system during the extraction and recovery phases of the oanel 30110.

STUDY ON THE RECLAMATION TECHNIQUE IN A SURFACE MINE WITH CROSS-PIT SYSTEM

A cross-pit system (CPS) could combine the excavation of coal and the reclamation of land together, thus it has been widely used in many countries. Based on a field experiment at Horse Creek mine in Illinois State of the United States, this paper deeply studies the reclamation technique of surface mining by a CPS and comprehensively evaluates its reclamation effect. Problerns and improvements of the reclamation technique are also discussed in this paper.

Research and development on cutting scale machine in the coal mine shaft

The deposit scale in the coal mine shaft usually causes serious accidents, such as making rope broken, cage seized or dropped. To solve this kind of problems, the re-search of the cutting scale mechanism was made, and a new type of removal scale equipment was made with using imported hard alloy material. The cutting experiment and actual cutting show that it can adapt to abominable condition in the shaft, such as narrow space, wet and excessive shaft crevice water and so on, and can work safely and reliably, and has high cutting scale efficiency. It can also cut out the deposit scale in the circular section of shaft.

An improved method to assess the required strength of cemented backfill in underground stopes with an open face

Backfill is increasingly used in underground mines to reduce the surface impact from the wastes produced by the mining operations. But the main objectives of backfilling are to improve ground stability and reduce ore dilution. To this end, the backfill in a stope must possess a minimum strength to remain self-standing during mining of an adjacent stope. This required strength is often estimated using a solution proposed by Mitchell and co-workers, which was based on a limit equilibrium analysis of a wedge exposed by the open face. In this paper, three dimensional numerical simulations have been performed to assess the behavior of the wedge model. A new limit equilibrium solution is proposed, based on the backfill displacements obtained from the simulations. Comparisons are made between the proposed solution and experimental and numerical modeling results. Compared with the previous solution, a better agreement is obtained between the new solution and experimental results for the required cohesion and factor of safety. For large scale(field) conditions, the results also show that the required strength obtained from the proposed solution corresponds quite well to the simulated backfill response.

GENERAL RELIABILITY THEORY STUDY ON SEMI-FLEXIBLE OUTPUT TYPE AND REPAIRABLE PRODUCTION SYSTEM

This paper puts forward the conceptions of semi-flexible units and semi-flexible system, and builds up the theory of semi-flexible output type and repairable production system general reliability analysis and general reliability design, which discusses the reliability problems of semi-flexible units and semi-flexible system from three aspects of time, task and capacity.