Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams

IMR OpenIR

	Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams
	Jinhua Wang 1; Bin Yu 2; Hongpu Kang 1; Guofa Wang 1; Debing Mao 1; Yuntao Liang 3; Pengfei Jiang 1
	2015-01-01
发表期刊	International Journal of Coal Science & Technology
ISSN	2095-8293
卷号	2 期号:2 页码:97-161
摘要	Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44% of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14m thick were extensively used in China. However, for coal seams with thickness greater than 14m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology & Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows: 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5m and a top-coal caving height of 15m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500–830MPa and a high extension ratio, and cable bolt material with a 1×19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as “low gas content, high gas emission”, are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9%. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a top-coal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed.
语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/159474
专题	中国科学院金属研究所
作者单位	1.China Coal Technology & Engineering Group 2.Datong Coal Mine Group Co., Ltd. 3.Institute of Metal Research, Chinese Academy of Sciences
推荐引用方式 GB/T 7714	Jinhua Wang,Bin Yu,Hongpu Kang,et al. Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams[J]. International Journal of Coal Science & Technology,2015,2(2):97-161.
APA	Jinhua Wang.,Bin Yu.,Hongpu Kang.,Guofa Wang.,Debing Mao.,...&Pengfei Jiang.(2015).Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams.International Journal of Coal Science & Technology,2(2),97-161.
MLA	Jinhua Wang,et al."Key technologies and equipment for a fully mechanized top-coal caving operation with a large mining height at ultra-thick coal seams".International Journal of Coal Science & Technology 2.2(2015):97-161.