Stability Mechanism and Control Technology for …
1 Introduction. Top-coal caving mining was first applied to the mining of steep coal seams in France, Spain, and the Socialist Federal Republic of Yugoslavia in …
Hypothesis of the multiple subsidence trough …
This paper describes a theory developed to predict the subsidence related to very steep and nearly vertical coal seams (70°–90°). This 'theory of the multiple …
EXTRACTION OF THICK COAL SEAMS
Thick seams are found in many countries, e.g., the former USSR, France, Spain, China, former Yugoslavia, Canada and India, etc. In India, over 60% of all known coal reserves …
Research on Top Coal Caving Technique in Steep and Extra-Thick Coal Seam
1. General situation of the working face The 2637 top coal caving face is located in the 6th cross-cut of the 12th level in Zhaogezhuang Mine. The elevation of the face is from -892.2m to -987.5m. The coal seam is stable and simple, with thickness of 8.58m to 14.27m, 10.54m on average, and angle of 44° to 72°, 51°on average.
Backfilling Material in Steep Underground Coal Mines
The coal seam is a monocline structure that belonged to the steep coal seam. The maximum dip angle is 76, the minimum dip angle is 60, and the average dip angle is 67 . The coal seam thickness is 1.23 m to 1.9 m, and the average coal thickness is 1.7 m. The lithology of the coal seam and overlaying and underlying strata are listed in Table1 ...
Probabilistic analysis of subsidence-induced strains at the …
DOI: 10.1016/S1365-1609(00)00046-0 Corpus ID: 129646198; Probabilistic analysis of subsidence-induced strains at the surface above steep seam mining @article{Torao2000ProbabilisticAO, title={Probabilistic analysis of subsidence-induced strains at the surface above steep seam mining}, author={Javier Tora{~n}o and Rafael …
An innovative approach to thin coal seam mining of …
1. Introduction. Thin coal seams are fairly pervasive in coal measures. For example, in China, the coal reserve of thin coal seams accounts for approximately 20% of total coal resource and its distribution covers over 85% of mining areas of China [1], [2].In order to maximise the recovery rate, the extraction of thin coal seams, especially for …
Profiling Function for Surface Subsidence Prediction in Mining Inclined
The coal seam dip angle also influences the stability of the coal mining face and the law of surface subsidence (Yao et al. 2017;Alejano et al. 1999; Asadi et al. 2004). In addition, support ...
Pressure Relief Mechanism and Gas Extraction Method …
In the Yaojie No. 3 coal mine, the #2 coal seam is the only one with commercial value. Its thickness is approximately 24.91 m, and its dip angle is approximately 55, i.e., the #2 coal seam is a typical steep and extra-thick one. Meanwhile, its average gas content is approximately 10 m3/t. The schematic cross section of the #2 coal seam …
Study on surface subsidence prediction method of shallow coal seam …
The backfill-strip mining is gradually applied to shallow coal seam mining for buildings protection because of its good effect, high resource recovery rate, and low filling cost (Guo et al. 2004; Wang et al. 2015a, b; Li et al. 2016; Zhu et al. 2019a, b).The traditional subsidence prediction method in backfill-strip mining is to divide the mining …
International Journal of Mining Science and …
Abstract. Ultra-thick steep coal seam mining will inevitably lead to the increase of greater and violent ground subsidence and deformation. A subsidence …
Hypothesis of the multiple subsidence trough …
Coalfields in the north of Spain (Asturias) are mainly steeply dipping and at considerable depth. There is widespread use of caving mining methods at the present time. This …
Evaluation of Surface Subsidence Due to Inclined Coal Seam Mining…
3311 Evaluation of Surface Subsidence Due to Inclined Coal Seam Mining. movement of the overlying strata was evident, and. its asymmetrical characteristics became relatively. stable when the ...
International Journal of Mining Science and Technology
For ultra-thick steep seams, fully-mechanized horizontal or inclined slicing top-coal caving method are specially used [8], [9].Mining-induced ground subsidence is governed by a number of factors, such as dip angle and thickness of seam [10], [15], [16], [17], mining method and roof control mode.Viewed as a whole, the ground subsidence is …
Study on first caving fracture mechanism of overlying roof rock in
The geological reserves of a steep mining field in Shanxi reaches 2.1 billion tons with a workable reserve of 1.06 billion tons. The coking coal of high quality was the main component of the coal source. The fully mechanized natural caving mining technology was used in the steep thick coal seam. The seam of panel 5-103 was No. 5 …
Roof Deformation Associated with Mining of Two Panels in …
Steeply dipping coal seams (i.e., inclination angle between 35° and 55°) account for approximately 15–20% of the coal reserves in China while mining in these seams account for 5–10% of China's production [].More than 50% of such steep coal seams are high-quality coking coal and anthracite, and more than 50% of the coal mines in western …
steep seam coal mining in spain
China's economy, the proportion of deep steep seam in China's coal mining will increase year by year [1]. However, compared with the shallow coal seam, the geological conditions of the deep coal seam will be more complex. For this kind of large dip angle, especially for the deep coal seam roadway with the influence of weak structural. Read More
Technical Aspects of Mining Rate Improvement in …
1. Introduction. Mining of thick and steeply-inclined hard coal deposits is one of the most di cult engineering challenges. These coal seams are mainly mined in China [1–3]. For …
Stability Mechanism and Control Technology for Fully
Top-coal caving mining was first applied to the mining of steep coal seams in France, Spain, ... The No. 2 coal seam is the primary mining seam of the No. 120210 working face in the Zaoquan Coal Mine (Ningxia Coal Industry Group). Its thickness ranges from 1.2 to 9.8 m, and the average thickness and depth are 8.15 and 400 m, …
(PDF) Study on Gas Comprehensive Control Technology in Steep …
2. combustion. The dip angle of coa l seam in north area is 43-46° and the gas concentration of coal seam. is more than 90%.In order to improve the gas drainage amount an d drainage rate of steep ...
Deformation Mechanism and Control Ttechnology …
The Xintie Coal Mine is under the administration of Qitaihe Branch, Heilongjiang Longmei Mining Group. As shown in Fig. 3, the primary-mining No. 49# steep coal seam, with a ground elevation of + …
Strata behavior in extra-thick coal seam mining with upward …
The #6 coal includes 6-1 and 6-2 coal seams, with the 6-2 seam as the main seam with an average thickness of 21.0 m and an inclination of 2.4°. The depth of the coal seam is 104 m with a 78.3 m bedrock. The Quaternary alluvium is 25.7 m thick and includes a 21.7 m aquifer. The roof of the 6-2 seam is 24.5 m thick grey sandstone.
Mining Spain s steep seams
Spain's coal deposits are characterized by variety: from steeply dipping seams (dipping by up to 70º) to narrow seams. There are roughly 20 underground mines using either conventional short/longwall mining or sub-level caving methods. Flat seams and seams with a gradient of up to 30º are mined by conventional longwall or shortwall …
Underground methods of extraction of thick coal …
Barring the diverse and often exceedingly site-specific methods for extraction of thick seams at steep gradients (exceeding 45 de- grees), the array of methods for …
Evaluating the Safety of Using the Combined Mining …
This study aimed to investigate the internal dislocation law of coal seam working face under coal pillars with different widths and evaluate the safety of using the combined mining of close-distance coal seams under different layer spacing. Based on elastic–plastic mechanics and mine pressure theory, theoretical calculation and …
Third US-India Working Group Meeting On Coal
1. opencast mining technology for working deep and steep seams (more than 300m depth) deposits of low grade coal. 2. improvement of availability & utilisation of hemm by mine management system. 3. steep seam mining technolgy –ripper dozer combination for hard coal mining. 4. methods for reduction of dilution in coal quality due to
(PDF) Theory and practice: Of fully mechanized …
A steeply dipping seam is one with. its dipping angle in the range of 35°-55 °. Mining of such coal s eams is recognized. to be difficult in the mining industry. The reserves of the steep coal ...
Breaking and mining-induced stress evolution of overlying …
Tu HS, Tu SH, Zhang C, Zhang L, Zhang XG (2017) Characteristics of the roof behaviors and mine pressure manifestations during the mining of steep coal seam. Arch Min Sci 62:871–891. Google Scholar Wang JN, Jiao JL (2016) Criteria of support stability in mining of steeply inclined thick coal seam. Int J Rock Mech Min Sci 82:22–35
Underground mining of steep seams in India
rsingh1_2@yahoo Thick Seam Mining and Strata Mechanics Department 2 Facts and figures about coal reserve and its exploitation trend in India reveals that the future of the industry lies with underground mining of coal. However, parameters like: depth cover, surface/sub-surface constraints, multi seam mining, steepness, contiguity and
(PDF) Thick Coal Seam Mining
mining of thick coal seam: Risk of overriding of pillars leading to premature collapse. Difficulty in strata control and its monitoring. Low percentage extraction, usually <50% when extraction is ...