外文翻译----研究现代高瓦斯矿井深部开采的关键技术.docx

英文原文study on critical, modern technology formining in gassy deep minesyuan lianghuainan mining (group) co. ltd., huainan, anhui 232001, chinaabstract: to achieve safe and highly efficient mining in the gassy, deep mines of the huainan collieries simultaneous coal and gas extraction, and the corresponding ventilation methods were developed. this includes a set of mining procedures and principles which help insure safe and efficient production. furthermore, green mining, meaning the comprehensive use of emitted gas, proper treatment of the environment and appropriate mine temperature control, is now standard. the concepts of modern mining and the principles of pressure relief are described. coal-gas simultaneous extraction and multi-pressure relief techniques were developed which require a combination of surface and underground gas extraction. the application of y-ventilation systems, of roadways retained along goafs, of stress control techniques for highly fragile mine roofs and of powerful, automatic and reliable mining equipment contributes to safe operation of modern deep mines. operating parameters for these techniques are described and the results of their use discussed.key words: gassy deep mining; modern mining; coal and gas simultaneous extraction; green miningclc number: td 821 introductiontypical in terms of gassy mines in china, the huainan mine areas have coal reserves of 50 billion tons and gas reserves of 5.928 billion m3. the coal seam is characterized as rich in gas content (1226 m3/t), deeply buried (3001500 m), extremely soft in texture (f = 0.20.8), low in permeability ( =0.0011 m2/(mpa2d) and high in gas pressure (pmax=6 mpa). ten production mines, with a gas emission rate of 820 m3/min, are all considered gassy mines. the area is geologically complicated. where multiple gassy coal seam groups are being worked, however, the bursting risk becomes high when working at depth. highpressure soft rocks surround the seam: the horizontal stress normally is 1.11.5 times the vertical stress. furthermore, over 80% of the roof is ranked as either iv or v on the fragility scale. these geological conditions present support problems and there are the usual underground temperature troubles.before 1997 gas was not satisfactorily extracted. the annual extraction rate was 5.2 million m3 and this average extraction rate was merely 3% of the gas production. therefore, gas accidents frequently occurred in the area and mine productivity remained ata low level. during the decade from 1987 to 1997 five extremely serious gas accidents occurred which caused a total of 293 deaths. in november of 1997 two extremely serious gas accidents occurred which caused 133 deaths. as a consequence of this, the area became notorious for frequent gas accidents and the annual coal output during that period remained as low as 810 million tons.with the gradual development of gassy deep mine working technology the area has witnessed much safer production, a record which gets better with each passing day.2 simultaneous coal-gas extraction technologiesgas troubles are mainly caused by working activities. hence, a combination of technologies, including things like working methods, working sequences, the principles of stratum movement caused by working, the principles of gas pressure relief or methods for gas extraction, should be considered simultaneously when designing coal-gas extraction methods.2.1 decision of pressure-relief seamin the huainan area there are 918 workable seams. they are numbered in reverse order to their levels as groups a, b, c, d and e and have a total workable thickness of 2234 m. the features of the coal seams are shown in table 1. with such a layout scientific selection of the initial working seam will be a critical decision to make.2.1.1 intrinsic safety principlewhen beginning to mine a coal seam group, for the sake of intrinsic safe mining, a seam comparatively low in gas content and burst risk should be selected as the pressure-relief seam for the following seams. for this purpose, in the huainan area, seam 11-2 is selected as the pressure-relief seam for seam 13-1 below it; seam b8 is selected for seam b6 above it; seam b10 is selected for seam b11 below it; and seam 15 is selected for seam 13 above it. these selections, and the corresponding workings, are all successful 23.the key technique of the pressure-relief seam lies in the roof bore-hole, or roadway drainage technology. the key to successful implementation of roof borehole, or roadway drainage, technology lies in the proper location of the gas concentration. theoretical studies, numerical simulations and in-situ surveys and measurements all show that under the present seam and roof conditions in the huainan area concentration of gas are located in circular cranny rings vertically825 m above the roof and 030 m below the air return way 46. therefore, roof boreholes and roadway drainage devices should be arranged at the locations where gas concentrates. also, gas extraction power and piping should satisfy the gas extraction demands. with the above demands satisfied one roof can extract gas at 30 m3/min and 70% of the gas can be extracted from the working face. for roof boreholes the optimal parameters for the negative pressure at the mouth of the hole, number of holes and the gas extraction rate are as follows: in an extraction field eight holes should be drilled, the interval between the two fields should be 100 m, the length of the hole should be 120 m and the negative extraction pressure should be 1620 kpa.2.1.2 principle of pressure relieving in cyclemining affected pressure-relief is an essential tool which improves the permeability of a seam. in the huainan areas seam 13-1(c13) is a thick seam high in gas content. to improve the permeability of this seam, seam 112, 70 m below, was selected as the pressure-relief seam. starting from the broken block of seam 11-2 and seam b8, 150 m below, was selected. in this way, the desired goals were successfully achieved. based on this experience, a technique for simultaneous extraction of coal and gas is implemented by creating working pressure relieving seams located a long distance, 70150 m, away. when the inter-seam distance was 70 m, and the relative inter-seam distance (the ratio of inter-seam distance to working height) was 35 times, by mining seam 11-2 to relieve pressure upwards the permeability for seam 13-1 was increased by 2880 times 3.relieving pressure downwards can be done only over a rather smaller distance. in this case, when the relative inter-seam distance is comparatively long multiple seams should be connected to the corresponding seam for sufficient pressure-relief. in the huainan areas, seam 4 in group b contains the largest volume of gas. by working coal seams b9, b8, b7 and b6 above b4 to relieve downward pressure the b4 gas pressure was reduced from 4.0 mpa to 0.2 mpa. additionally, the permeability increased hundreds of times. in this way, a cyclic technique involving simultaneous extraction of coal and gas by working multiple seams separated by a short distanceof 20120 m is capable of safely controlling the coal gas.2.1.3 principle for maximal resources recoverywhen a thin seam is selected as the pressure-relief seam coal resource recovery can be increased. in the huainan areas all the thin seams were located through geological surveys. those seams whose thickness reaches 0.7 m were chosen as pressure-relief seams. therefore, the coal recovery rate has reached 82%.2.2 combination of surface and underground gas extractionboreholes and roadways should be arranged in relation to different underground gas resources; holes are drilled along the seam, through the seam and in the goaf. drainage roadways can be divided into high-located roadway, low-located roadways and tailgates. when pressure is relieved, and permeability improved, by drilling holes through the seam the gas extraction rate can be as high as 60% within 120 d. through studies, it was discovered that a period of active gas flow occurs as shown in fig. 1. fig. 1 describes coal seam pressure variation as a function of gas flow. once pressure relief begins the first 20 days constitute the pressure relief, and increased stress activity, period which has an increasing gas extraction volume. the duration from the 20th to the 80th day constitutes the stable period for pressure relief and stress activity as the permeability coefficient reaches a peak and the gas extraction rate stabilizes. during this period the average gas extraction volume was over 1.0 m3/min for the four holes. from the 80th day on, as the coal seam becomes consolidated, the permeability coefficient decreases and the gas extraction rate drops in line with the negative index. for this reason, during the pressure relief and active gas period, as much gas a possible should be extracted so that the gas extraction rate can be raised.a small shaft can be sunk from the surface in the mining and pressure-relief affected area to extract gas from the mining area. the structure of the shaft sunk from the surface is shown in fig. 2. the shaft can be as deep as 650680.3 m with a diameter of 177.8 mm. the thickness of the target seam is 7.910.5 m.observations on-site have shown that the maximum gas extraction volume of a single shaft has reached 22190 m3/d with an average gas extraction volume of 14943 m3/d 2. the concentration for the gas so extracted has reached 95% and the annual gas extraction volume of a single shaft has reached 3 million m3. in the mining affected zone, the drainage radius of a single shaft is 211 m. the shaft can be used to extract gas from mining affected zones or from goafs.2.3 intrinsically safe ventilation techniqueat the gassy working face y-ventilation technology, consisting of two inlets and an outlet and the corresponding gob-side entry retaining technology, were applied. such technologies can be an appropriate solution at the working face and for upper-corner gas problems, and to remove heat diffused by the goaf. this technique of working without a pillar can reduce the coal losses to the minimum and expand the scope of the mining pressure-relief area.the key technique for gob-side entry retaining depends on the intensity, and how far the required transportation, of the filling material. a new material consisting of a concrete cream material is used for the filling. fly-ash composes about the 30% of the dry weight of this filler. on-site observations indicate that one day after filling the compressive strength will be 3 mpa and after 28 days the strength will be 14 mpa. this new material is weatherproof so the workedroadway remains safe and stable. in the huainan areas a concrete pump is used for material transport over a distance greater than 400 m; the maximum distance can be 1200 m.3 conclusionsmodern extraction principles for gassy mines are intrinsic safety, efficient integration and green mining. since 1998 operators at the huainan mines have been promoting this technology and have obtained apparent economic profits and social benefits.consider these contrasts. during the period from 1997 to 2005 there were ten mines in the area. also during this period the gas extraction volume increased from 10 million m3 to 150 million m3, the annual coal production increased from 10 million tons to 30 million tons, the annual production of a working face increased from 0.6 million tons to 3.63 million tons and the gas extraction rate increased from 5% to 70%. meanwhile, extremely serious gas explosions were much better controlled, as indicated by the drop in the fatality rate from 4.01 to 0.5 per million tons of coal.as mining goes deeper and deeper problems with gas, pressure, temperature and so on become increasingly serious. in particular coal and gas out-burst prevention techniques will become the most important problem for gassy mines. therefore, systematic research should continue to be conducted on modern mining technology for the sake of safe, efficient and green mining.中文译文研究现代高瓦斯矿井深部开采的关键技术袁亮淮南矿业（集团）有限公司，安徽淮南232001，中国摘要：为了实现安全，高效的开采高瓦斯煤矿，淮南矿业集团进行深部煤和天然气共采的同时，发展相应的通风方法。这包括建立采矿作业的程序和原则，以确保安全和高效的生产。此外，绿色开采是现在的标准，也就是综合进行矿井瓦斯排放，妥善处理环境和适当的控制矿井温度。该理论阐述的是现代化采矿和压力卸载的原则。开发了煤与瓦斯共采技术，它提取的是地表和地下的混合气体。该系统应用y型通风巷道，沿空留巷技术，压力控制技术控制坚硬顶板和周期来压原理，且自动化和安全可靠的现代化采矿设备能有助于深矿井的安全运行。研究这些技术的操作参数，并对其使用结果进行讨论。关键词：深部瓦斯开采；现代采矿；煤与瓦斯共采；绿色开采1 介绍就中国典型的高瓦斯矿井而言，在淮南矿区的煤炭储量有500亿吨，天然气59.28亿m3。这个地区煤层的特点是，瓦斯含量高（12-26m3/t），埋藏较深（300-1500m），质地非常软（f = 0.20.8），渗透性低（ =0.0011m2/(mpa2d)），压力较高(pmax=6 mpa)。10个生产矿井的瓦斯排放率达到820m3/min，被认为是高瓦斯矿井。该地区地质条件复杂。当开采多瓦斯的煤层群时，在深处得爆破工作就很危险。高应力的软岩环绕着煤层：水平应力通常是垂直应力的1.11.5倍。此外，超过80的顶板被评为iv或者v级以上的易碎的性。这些是目前的地质条件目前所呈现的问题，且一般伴随有地热的问题。在1997年之前瓦斯气体是不能令人满意地提取的。每年提取率为5.2亿立方米，这个平均提取率只是天然气生产率的3。因此，瓦斯事故频繁发生的地区，矿山生产力水平较低。从1987到1997发生了五次极端严重的瓦斯气体爆炸事故，总共导致293人死亡。在1997年11月两个极为严重的意外瓦斯事故造成133人死亡。由于这一原因，该地区成为瓦斯事故频繁地区，而在此期间每年的煤炭产量依然较低，为8-10万吨。随着逐渐在高瓦斯深矿井中应用技术，该地区的生产逐渐安全起来，以后这个纪录将会越来越好。2 煤与瓦斯共采技术天然气的问题主要是由于开采活动引起的。因此，一组技术组合，包括许多东西，像工作方法，工作序列，由工作引起的地层活动的规律，瓦斯降压的原则或瓦斯开采的方法，在设计煤与瓦斯共采方法时都应同时考虑。2.1煤层减压的措施在淮南地区有9-18可采煤层。他们以相反的顺序被编号，为a，b，c，d，e，可采的煤层总厚度度为22-34m。煤层的特点见表1。有了这样的一个布局，科学的选择初始开采煤层将是一个重要的决定。2.1.1内在安全原则当开采一组煤层群时，为了真正意义上的安全采矿，应选择瓦斯含量和突发风险比较低的煤层，作为下降煤层的卸压煤层。为此，在淮南地区，11-2煤层被选定为卸压煤层，因为13-1在它下方；b8 被选择由于 b6 在上方；b10 被选择由于 b11在下方；15被选择因为 13在上方。这些选择和相应的工作机制是成功的。煤层卸压的关键技术在于顶板钻孔中和巷道排水技术。对顶板钻孔和巷道排水成功实施的关键技术在于瓦斯浓度的适当位置。理论研究，数值模拟和现场调查和测量表明，在淮南地区目前的煤层和顶板条件下，瓦斯气体位于循环裂隙圈中垂直顶板825 m，030 m。因此，顶板钻孔和巷道排水设备应布置在瓦斯气体较浓的地点。此外，电力和天然气开采的天然气管道应满足提取要求。满足上述条件的一个顶板瓦斯提取能达30 m3/min，70%的瓦斯能从工作面提取出来。顶板钻孔的最优负压参数在洞口，钻孔数量和瓦斯提取率如下：在一个取样范围内应打8个钻孔，在这两个取样之间的间隔应该是100米，洞长应该是123m，负提取压力应为1620 kpa。2.1.2周期缓解压力的原则采掘影响减压阀是提高煤层透气性的重要工具之一。在淮南地区煤层13-1（c13）是一个厚煤层且瓦斯含量高的煤层。为了提高本煤层透气性，煤层11-2，70m以下，被选定为降压煤层。从破碎带和煤层b8，150m以下被选择。在这种方式下，成功地实现了预期目标。根据这一经验，煤与瓦斯共采的技术，通过建立位于70150 m远的一个工作减压层。当断裂层距离