采矿英语文献

1、精选优质文档-倾情为你奉上Control and prevention of gas outburstsMaría B. Díaz Aguado C. González （International Journal of Coal Geology 69(2007)253-266）Abstract： Underground coal mines have always had to control the presence of different gases in the mining environment. Among these gases, methane

2、 is the most important one, since it is inherent to coal. Despite of the technical developments in recent decades, methane hazards have not yet been fully avoided. This is partly due to the increasing depths of modern mines, where methane emissions are higher, and also to other mining related circum

3、stances, such as the increase in production rates and its consequences: difficulties in controlling the increasing methane levels, increasing mechanization, the use of explosives and not paying close attention to methane control systems. The main purposes of this paper are to establish site measurem

4、ents using some critical parameters that are not part of the standard mining control methods for risk assessment and to analyze the gas behavior of subvertical coal seams in deep mines in order to prevent gas incidents from occurring. The ultimate goal is the improvement in mining conditions and the

5、refore in safety conditions.Key words： Coal mines，coal-seam methane，gas pressure，permeability，gas outburst- potential. 专心-专注-专业一.Introduction Coalbed and coal mine methane research is thriving due to the fact that power generation from coal mine methane will continue to be a growing industry over th

6、e coming years in certain countries. For instance, China, where 790 Mm3 of CH4 were drained off in 1999 (Huang, 2000), has 30 Tm3 of estimated CBM potential in the developed mining areas (Zhu, 2000). The estimate by Tyler et al. (1992) of the inplace gas in the United States is about 19 Tm3, while G

7、ermany's total estimated coalbed methane resources are 3 Tm3, very similar to Polish or English resources (World Coal Institute, 1998). This increase in the CBM commerce has opened up new lines of research and has allowed the scientific community to increase its knowledge of some of the properti

8、esof coal and of methane gas, above all with respect to the properties that determine gas flow, which until now had not been sufficiently analyzed. Some of these parameters are the same ones that affect the occurrence of coal mining hazards, as methane has the potential to become a source of differe

9、nt fatal or nonfatal disastrous events. 二.Description of the Asturian Central basin and of the 8thCoalbed The 8th Coalbed of the RiosaOlloniego unit, located in the Southwest of the Asturian Central Coal Basin (the largest coal basin in the Cantabrian Mountains, IGME, 1985), has CBM potential of abo

10、ut 4.81 Gm3. This is around 19.8% of the estimated resources of the Asturian Central Basin and 12.8 % of the total assessed CBM resources in Spain (Zapatero et al., 2004). 3.84 Gm3 of the CBM potential of the 8th Coal-bed belongs to San Nicolás and Montsacro: 1.08 Gm3 to San Nicolás area a

11、nd 2.76Gm3 to Riosa, down to the 800m level (IGME, 2002). The minable coalbeds of this unit are concentrated in Westphalian continental sediments (Suárez-Ruiz and Jiménez, 2004). The RiosaOlloniego geological unit consists of three seams series: Esperanza, with a total thickness of 350 m,

12、contains 36 coalbeds with a cumulative coal thickness of 3.5 to 6.5 m; Pudingas, which is 700 m thick, has 35 coalbeds with a thickness of 57m; whereas the Canales series, the most important one, I 800 m thick, with 812 coalbeds that sum up to 1215 m thick. This series, which contains the 8th Coalbe

13、d, the coal-bed of interest in this study, has a total thickness of 10.26mat SanNicolás and 15.13matMontsacro (Pendás et al., 2004). Fig. 1 shows the geological map of the two coal mines, whereas Fig. 2represents a front view of both mines and the location of the instrumented areas. In thi

14、s particular study, the 8th Coalbed is situated at a depth of between 993 and 1017 m, in an area of low seismi intensity. Instantaneous outbursts pose a hazard to safe, productive extraction of coal in both mines. The mechanisms of gas outbursts are still unresolved but include the effect of stress,

15、 gas content and properties of the coal. Other factors such as geological features, mining methods, bord and pillar workings or increase in rate of advance may combine to exacerbate the problem (Beamish and Crosdale, 1998). Some of the main properties of the 8th Coalbed favoring gas outbursts (Creed

16、y and Garner, 2001; Díaz Aguado, 2004) had been previously studied by the mining company, in their internal reports M.B. Díaz Aguado, C. González Nicieza / International Journal of Coal Geology 69(2007)253 Fig. 1. Geological map.As well as in the different research studies cited in Se

17、ction The geological structure of the basin, the stress state of the coal-bed and its surrounding wall rock and some properties of both coal-bearing strata and the coalbed itself. The next paragraphs summarize the state of the research when this project started. Many researchers have studied relatio

18、nships between coal outbursts and geological factors. Cao et al. (2001), found that, in the four mining districts analyzed, outbursts occurred within tectonically altered zones surrounding reverse faults; this could help to delimit outburstprone zones. In the 8th Coalbed, some minor outbursts in the

19、 past could be related to faults or changes in coal seam thickness. Hence, general geological inspections are carried out systematically, as well as daily monitoring of any possible anomalies. But, in any case, some other outbursts could be related neither to local nor general faults. Fig. 2. Genera

20、l location of the study area. M.B. Díaz Aguado, C. González Nicieza / International Journal of Coal Geology 69 (2007) 253266 For some years now, the technical experts in charge of the mine have been studying the stress state of the coalbed by means of theoretical calculations of face end o

21、r residual rock mass projections that indicated potential risk areas, based on Russian standards (Safety Regulations for Coal and Oil Shale Miners, 1973).Assuming that there was an initial approach to the stress state, this parameter was therefore not included in the research study presented in this

22、 paper. In the Central Asturian Coal Basin, both the porosity and permeability of the coal-bearing strata are very low,the cleat structure is poorly developed and cleats are usually water-filled or even mineralized. Consequently, of 5.10 m3/t. In some countries, such as Australia (Beamish and Crosda

23、le, 1998) or Germany, a gas outburst risk value has been established when methane concentration exceeds 9 m3/t (although close to areas of overpressure, this risk value descends to 5.5 m3/t). As the average gas contents in the coalbed are comparable with those of the Ruhr Basin (which according to F

24、reudenberg et al., 1996, vary from 0 to 15 m3/t), the values in the 8th Coalbed would be close to the risk values. Desorption rate was considered the most important parameter by Williams and Weissmann (1995), in conjunction with the gas pressure gradient ahead of the face. Gas desorption rate (V1) h

25、as been defined as the volume of methane, expressed in cm3, that is desorbed from a 10 g coal sample, with a grain size between 0.5 and 0.8 mm, during a period of time of 35 s (fromsecond 35 to 70 of the test). Desorption rates have been calculated from samples taken at 2 m, 3 m and 7 m, following t

26、he proceedings of the Technical Specification 0307-2-92 of the Spanish Ministry of Industry. The average values obtained during the research are: 0.3 cm3 / (10 g·35 s) at 2 m depth, 0.5 cm3 / (10 g·35 s) at 3 m and 1.6 cm3 / (10 g·35 s) at the only paths for methane flow are open frac

27、tures. Coal gas content is one of the main parameters that had been previously analyzed. The methane concentration in the Central Asturian Basin varies between 4 and 14 m3/t of coal (Suárez Fernández, 1998). Particularly, in the RiosaOlloniego unit, the gas content varies from 3.79 to 9.89

28、 m3/t of coal (Pendás et al., 2004). During the research, the measured values in the area of study have varied between 4.95 and 8.10 m3/t, with an average value7m.Maximumvalues were of 1.7 cm3 / (10 g·35 s) at 2m depth, 3.3 at 3 m and up to 4.3 cm3 / (10 g·35 s) at 7 m.The initial cri

29、tical safety value to avoid gas outbursts in the 8th Coalbed was 2 cm3 / (10 g·35 s). Due to incidents detected during this research study, the limit value was reduced to 1.5 cm3 / (10 g·35 s). But other properties, such as coal gas pressure, the structure of the coal itself and permeabili

30、ty, had beeninsufficiently characterized in the Riosa Olloniego unit before this research study. Two methods had been previously employed to determine the gas pressure in the mine: the Russian theoretical calculations for the analysis of the stress state and the indirect measurements of the gas pres

31、sure obtained by applying criteria developed for the coalbeds of the Ruhr Basin (Germany), Poland and the former Soviet Union. These indirect measurements were the Jahns or borehole fines test (Braüner, 1994), which establishes a potential hazard when the fines exceed a limiting value. Although

32、 there are tabulated values for the coalbeds of the Ruhr Basin, it is not the case for the coals of the RiosaOlloniego unit. Therefore, in this paper an improvement to the gas pressure measurement technique is proposed by developing a method and a device capable of directly measuring in situ pressur

33、es. The 8th Coalbed is a friable bituminous coal, high in vitrinite content, locally transformed into foliated fabrics which, when subjected to abutment pressure, block methane migration into working faces (Alpern, 1970). With low volatile content, it was formed during the later stages of coalificat

34、ion and, as stated by Flores (1998) this corresponds to a large amount of methane generated. Moreover, the coal is subject to sudden variations in thickness (that result in unpredictable mining conditions) and to bed-parallel shearing within the coalbed, that has been considered an influence on gas

35、outbursts (Li, 2001). Its permeability had never been quantified before in this mining area. Thus, during research in the 8th Coalbed it was decided to perform in situ tests to measure pressure transients, to obtain site values that will allow future calculations of site permeability, in order to ve

36、rify if it is less than 5 mD, limit value which, after Lama and Bodziony (1998), makes a coalbed liable to outbursts. Therefore, in this study we attempted to characterize gas pressure and pressure transients, for their importance in the occurrence of gas outbursts or events in which a violent coal

37、outburst occurs due to the sudden release of energy, accompanied by the release of significant amount of gas (González Nicieza et al.,2001), either in breaking or in development of the coalbed (Hardgraves, 1983). 三.Conclusions Coalbed is still a major hazard affecting safety andproductivity in

38、some underground coal mines. This paper highlights the propensity of the 8th Coalbed to give rise to gas outbursts, due to fulfilling a series of risk factors, that have been quantified for 8th Coalbed for the first time and that are very related to mining hazards: gas pressure and its variation, wi

39、th high valuesmeasured in the coalbed, obtaining lower registers at Montsacro than at San Nicolás (where 480 kPa were reached in the gas pressure measurements at the greatest depth). These parameters, together with the systematic measurement of concentration and desorption rate that were alread

40、y being carried out by the mine staff, require monitoring and control. A gas-measurement-tube set was designed, for measuring gas pressure and its variations as well as the influence of nearby workings to determine outburstprone areas. The efficacy of injection as a preventative measure was shown by

41、 means of these measurement tubes. References1 Alexeev, D.M., 2004. 2 True triaxial loading apparatus and its application to coal outburst prediction. Int. J. Coal Geol. 58, 245250. 3 Alpern, B., 1970. Tectonics and gas deposit in coalfields: a bibliographical study and examples of application. Int.

42、 J. Rock Mech. Min. Sci. 7, 6776. 4 Beamish, B.B., Crosdale, J.P., 1998. Instantaneous outbursts in underground coal mines: an overview and association with coal type. Int. J. Coal Geol. 35, 2755. 5 Braüner, G., 1994. Rockbursts in Coal Mines and Their Prevention. Balkema, Rotterdam, Netherland

43、s. 137 pp. 6 Cao, Y., He, D., Glick, D.C., 2001. Coal and gas outbursts in footwalls of reverse faults. Int. J. Coal Geol. 48, 4763. 7 Durucan, S., Edwards, J.S., 1986. The effects of stress and fracturing on permeability of coal Min. Sci. Technol. 3, 205216. 8 Flores, R.M., 1998. Coalbed methane: f

44、rom hazard to resource. Int. J. Coal Geol. 35, 326.瓦斯治理和预防M.B.迪亚斯·阿瓜多、尔冈萨雷斯·尼茨迊（煤炭地质69（2007）253-266国际杂志）摘要：在煤矿井下开采环境中必须控制着不同气体的存在。在这些气体中，甲烷是最重要的一个，它伴随着煤而产生。虽然有几十年内科技的发展，但瓦斯灾害未能完全避免。这种情况部分由于现代矿井开采深度的增加，甲烷排放量增高；也和其他开采相关情况有关，如生产率的提高和它的后果：在控制日益增加的甲烷含量方面有很多困难，日益增加的机械化，爆炸品的使用，不太关注瓦斯控制系统。本文的主要目的是

45、使用一些不属于用于风险评估的标准采矿控制方法的一些关键参数，建立现场测量，并分析直立煤层深部煤矿瓦斯行为，以防止偶然发生瓦斯事故。最终目标是开采条件的改善，安全条件的提高。关键词：煤矿，煤层气，气体压力，渗透率，瓦斯突出。一.简介由于某些国家在未来几年内，煤矿瓦斯气发电将会是一个继续增长的工业，因此煤层和煤矿瓦斯研究得到蓬勃发展。例如，中国，其中在1999年（黄，2000）有790 Mm3的甲烷涌出，估计发达矿区煤层气潜力为30 Tm3（朱，2000）。由泰勒等人（1992）的估计，在美国地区天然气约为19 Tm3，而德国的煤层气资源总量估计有3 Tm3，与波兰文或英文资源非常相似（世界煤炭研

46、究所，1998年）。煤层气商业的增加开辟了研究的新领域，也使科学界增加对煤炭和甲烷气体的知识，尤其是关于决定气体流动的属性，直到现在还没有得到充分的分析。其中一些参数影响了煤炭开采危害的发生，甲烷有可能成为一个不同的致命或非致命的灾难性事件的源头。二.阿斯图里亚斯中央盆地第8煤层气的描述RiosaOlloniego单位的第8煤层，坐落于阿斯图里亚斯中央煤盆地西南（在坎塔布连山脉，IGME，1985年最大的煤盆地），具有潜在煤层气约4.81 Gm3。这是大约19.8的阿斯图里亚斯中部盆地的资源估计数和西班牙煤层气资源总估值的12.8（萨帕特罗等，2004）。第8煤层潜在煤层气的3.84 Gm3属

47、于圣尼古拉斯和蒙托萨克：圣尼古拉斯的1.08 Gm3和利萨的2.76 Gm3，降至水平800米以下（IGME，2002）。 该区煤层主要集中在威斯特伐利亚（苏亚雷斯- 瑞兹和希门尼斯，2004年）的陆相沉积中。Riosa- Olloniego地质单元的三种些列的煤层组成：总厚度为350 m的埃斯佩朗莎，包含3-6个为3.5-6.5 m厚煤层的煤床; 总厚度700 m的布丁伽斯，包含3-5个5-7 m厚煤层的煤层；而卡纳莱斯系列，最重要的一个，有8-12个煤层，总厚度800 m，累计厚度12-15 m。这个系列，其中包含第8煤层，是这个研究中的利益所在，拥有总厚度达10.26 mat的圣尼古拉斯

48、和15.13 mat的蒙托萨克（Pendás等，2004）。图1显示了两个煤矿地质图，而图2显示两个矿井正视图和仪器的位置。在这项特殊的研究中，第8煤层气位于深度993和1017 m之间，一个低的地震强度区域。在这两个煤矿的煤炭生产中，瞬时爆发对安全造成危害。瓦斯爆炸的机制仍然没有得到解决，但包括压力，瓦斯含量和煤的性质的影响。其他因素，如地质特征，开采方法，巷道和支柱的运作，推进增加速率可使问题进一步恶化（比米什和克洛斯戴勒，1998年）。易于煤层瓦斯突出（科瑞迪与加纳，2001年，迪亚斯·阿瓜多，2004年）的第8煤层的一些主要属性以前曾由矿业公司研究，出现在其内部报告

49、。M.B.迪亚斯·阿瓜多、尔冈萨雷斯·尼茨迊/煤炭地质69（2007）253-266国际杂志图1 地质图以及在不同的研究报告中引用部分盆地地质结构，煤层压力状态及周边围岩，还有含煤层及煤层本身两者的一些属性。接下来的段落总结了本研究项目开始时的状态。许多研究人员研究瓦斯爆炸与地质因素的关系。曹等（2001年）发现，在四个矿区进行了分析，爆炸发生在周围是逆断层蚀变构造区；这将有助于划定爆炸易发区。在第8煤层，过去的一些轻微的爆炸可能与断层或煤层厚度变化联系在一起。因此，进行常规系统地地址检查，以及日常监测任何可能出现的异常情况。但是，无论如何，总有一些其他的爆炸可能既与当地也

50、与一般断层无关。图2 常规位置的研究区域。 M.B.迪亚斯·阿瓜多、尔冈萨雷斯·尼茨迊/煤炭地质69（2007）253-266国际杂志一些年来，依据俄罗斯标准（安全煤和油页岩的矿工，1973年规例），负责煤矿的技术专家已研究了煤层压力状态下通过能够揭示潜在危险区域的工作面的理论计算端头或残留岩体的预测，指出潜在的危险地区。假设有一个初步的办法来应对压力状态，这个参数因此没有包括在这个研究性学习的文件中。在阿斯图里亚斯煤中央盆地，无论是孔隙度还是含煤层的渗透率都非常低，夹板结构不发达，夹板通常充满水，甚至矿化。因此， 5.10 m3/t。在一些国家，诸如澳大利亚（比米什和克洛

51、斯戴勒，1998年）或德国，一个瓦斯爆炸的风险值已建立，当甲烷浓度超过9 m3/t（尽管接近超压区，此风险值下降到5.5 m3/t）。由于平均煤层瓦斯含量平均与那些鲁尔盆地（根据科德宝集团等。1996年，从0变化到15 m3/t）相当，在第8煤层值将接近的风险值。 脱附速率和工作面前方瓦斯压力梯度被威廉姆斯和韦斯曼（1995年）认为是最重要的参数。瓦斯解吸率（V1）被定义为，在35 s时间内，由10 g晶粒尺寸在0.5和0.8 mm之间煤的样解吸得到甲烷立方厘米体积量。解吸率计算，从2 m，3 m和7 m处得到样本，遵循西班牙工业部技术规范0307-2-92。研究中得到的平均值是：在2 m的深度0.3 cm3/（10 g·35 s），在3 m的深度0.5 cm3/（10 g·35 s）和在甲烷流动唯一路径开放断裂情