In situ investigations into overburden failures of a super-thick coal seam for longwall top coal caving. Int. J. ... China University of Mining and Technology, Xuzhou, 221116, China. Zhixiang Tan.
Longwall top coal caving (LTCC) is a special type of longwall mining applicable to very thick seams (greater than 4.5m) where good quality coal is being left because "conventional" longwall equipment has not yet been designed to operate successfully beyond around 5m mining height. It enables an increased recovery for only an …
Top coal caving technologies is not a novelty. The first experimental tests of top coal caving were undertaken well before engineering of longwall mining systems and hydraulically-powered shield-type roof supports. In the USSR experiments with top coal caving in the supported area of roadways were initiated in the 1930s [1].
Along with it, a prospect of thick seam mining by mechanized longwall and its variants like Longwall Top Coal Caving (LTCC), Sub-Level Caving, etc. is proposed as a future thick seam mining method ...
Longwall top coal caving (LTCC) technology is one of the effective methods for extracting thick and extra-thick coal seams. Since it is introduced into China in 1982, LTCC has …
China is the world's largest coal-producing country and its coal production was 3.57 billion ton in 2014, of which underground longwall mining accounts for more than 85%.
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 the early twentieth century; the technique was later extended to thick coal seams in the mines of the Soviet Union, France, and other countries during the early 1950s [].Fully mechanized …
The recovery ratio of longwall top coal caving (LTCC) technology is an important measure of its effectiveness. However, the recovery ratio of single-opening sequential caving …
Previously conducted studies have established that the sudden collapse of large areas of overhanging roofs in longwall working faces can cause shock loads and wind blast. In order to solve the problem of the hard and stable roof (HSR) being difficult to collapse in the initial mining stage, a combination of theoretical analysis and numerical …
In order to study the fracture patterns of hard main roof in longwall top coal caving (LTCC) with large mining height, a two-dimensional physical similarity model was created to simulate the mining process of No. 8100 large mining height face in Tongxin coal mine, China. The results show that there are three positions of broken line in hard …
1. Introduction. Longwall Top Coal Caving (LTCC) can provide substantially less economic sensitivity and a reduced level of technical risk over other thick seam mining methods. 1 A reliable evaluation of LTCC's applicability at the feasibility stage of a new mining project is therefore of importance to the effective and productive extraction of …
As the energy crisis continues to intensify, the basic industrial status of coal as the main source of energy has not changed because it is still considered the main energy source in the future (Le et al. 2017; Hao et al. 2017).Thick coal seams and extra-thick coal seams occupy an important share in coal resource mining, and thick coal seam mining …
1.9 It is pertinent to note that the longwall top coal caving (LTCC) is the method which is extensively deployed for extracting thick and extra-thick coal seams in China. ... 4.5 Joy Global Though global underground coal mining technology has r- pur, ECL 4.78m 12CM15 made very rapid strides, it has been relatively stagnant in 2 Jhanjra R V, 5m ...
The recovery rate and safety of thick coal seam under aquifer are greatly improved by filling mining in layered roadway . Wen et al. (2022) comparatively analyzed the traditional longwall mining ...
This paper presents a mining technology that enables the continuous conversion from top coal caving (TCC) to multi-slice mining (MSM). The technology helps operations overcome challenges with ...
In longwall top coal caving (LTCC) mining methods, problems such as large deformations, loss of coal resources, and excavation relay out of balance are often encountered with …
The re-mined face using top coal caving system is the most applicable method for recovering the remaining reserves of a previous partially-mined thick coal seam. However, this mining method may encounter the problems of low recovery and unpredicted geological conditions. A numerical model is developed using PFC2D for studying the …
Longwall top coal caving (LTCC) mining is the most ... mining technology will constitute the development direction and target for extra‐thick coal seam extrac-tion.41 Indeed, ...
Longwall Mining Technologies. As coal mining technology and equipment are improved in China to meet the growing demand for coal, high-intensity longwall mining is becoming increasingly common. The main mining methods are fully mechanized full seam mining or fully mechanized top-coal caving (Guo et al. 2019).
Yasitli NE, Unver B (2005) 3D numerical modeling of longwall mining with top-coal caving. Int J Rock Mech Min Sci 42:219–235. Article Google Scholar ... Research report 2008-1, Technology Center of Datong Coal Mine Group Corporation. Yu B, Zhao J, Kuang TJ, Meng XB (2015) In situ investigations into overburden failures of a super-thick …
The longwall top-coal caving (LTCC) mining method has been widely used in the underground coal mine in China (Mangal and Paul, 2016).During the mining process, as the working face advances, the overlying strata over the coal seam are disturbed by mining, which will cause serious roof activities such as subsidence, …
Moreover, the range of the interaction between the caving strata and the overburden in gob was discussed, which provides a reference when using a continuum method to simulate longwall mining. 1. Introduction. Longwall mining is a widely used underground coal extraction method for its high production and recovery rate.
Understanding the characteristics of drawing body shape is essential for optimization of drawing parameters in longwall top coal caving mining. In this study, both physical experiments and theoretical analysis are employed to investigate these characteristics and derive a theoretical equation for the drawing body shape along the …
Table 1 shows that the minimum thickness to be a thick seam is in the range of 3.0–4.8 m, the coal seam with a thickness over 3.5 m is considered as a thick coal seam in China. Based on the most advanced longwall mining technology, the coal seam with a thickness between 3.5 to 7 m is defined as the thick coal seam, and the coal seam …
Longwall top coal caving (LTCC) is a part of longwall mining that is applicable for thick coal seams.
There are more than 7000 sensors installed in current longwall mining systems. The big data obtained and fast communication technology have been fully utilized to improve and solve operational problems in real time. …
Abstract In longwall top coal caving (LTCC) mining methods, problems such as large deformations, loss of coal resources, and excavation relay out of balance are often …
Thick seam mining technologies; Longwall top coal caving; Risks; Indian geo-mining conditions; Download conference paper PDF 1 Introduction. In India, presently, thick seams up to a thickness of 4.5 m are effectively extracted from underground by only two methods, namely Bord and Pillar mining in conjunction with continuous miner and …
Longwall top coal caving (LTCC) mining is the most efficient method for thick and extra-thick coal seam extraction. ... In the near future, intelligent LTCC mining technology will constitute the development direction and target for extra-thick coal seam extraction. 41 Indeed, coal mining is in the process of being transformed from …
In longwall top coal caving (LTCC) mining methods, problems such as large deformations, loss of coal resources, and excavation relay out of balance are often encountered with the increased ...
The geomechanical model of the powered roof support-top coal-roof rock system is developed. For investigation of disintegration processes in top coal of thick seam, numerical modeling with finite element discretization of a study domain is carried out using the authors' original code. The computational experiment reveals stress distribution in …
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WebLongwall Top Coal Caving (LTCC) technology. Yancoal introduced the Longwall Top Coal Caving (LTCC) mining technology to Australia at its Austar mine in 2006. Developed in China, top coal caving uses a …
Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Controlled caving of rock mass is a prerequisite pro thriving exploitation of coal deposits by longwall retreat with caving …
Dynamic sublevel caving technology (DSCT) proposed by the researchers is one of effective methods to solve the problems of low top coal recovery, poor drawing balance and support stability in longwall top coal caving (LTCC) with large dip angle. To investigate the reasonable number of supports in a sublevel (N) and the top coal drawing …
the extraction of coal from underground mining is a clean coal technology, the production from opencast mining andis dominating underground mining for 5 decades, aroundand is being ... 1.9 It is pertinent to note that the longwall top coal caving (LTCC) is the method which is extensively deployed for extracting thick and extra-thick coal seams ...
During the initial process of mining a longwall working face, it is often found that the roof will not collapse readily, which increases the risk of later roof collapse disasters. Explosive and hydraulic fracturing are common roof weakening techniques; however, they have certain limitations. In the present study, CO2 fracturing was used for roof weakening …
1. Introduction. According to the studies conducted by Sun Chuang (Sun et al. 2021) and other scholars on regarding the work face, main features are large inclination angles and mining heights, compound roofs, the high tendency to separation and collapse, loose coal body, often severe rib spalling and roof collapse tending to occur in the middle …
Multi-slicing mining, top-coal caving mining, and large-cutting-height mining are the three common methods for extracting the thick coal seams in China. The multi …
