Assuming that the top coal above the support F I G U R E 1 Sketch map of the longwall top coal caving mining method is a loose granular medium, Wang et al. proposed a granular flow model for top ...
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 technology in thick and extra-thick coal seams needs improvement. To address this, an independent cluster-group caving technology is proposed in this study.
8.2.2.1 Longwall coal miningIntroduction. Longwall mining is a fast and mechanized method of coal mining where a large "wall" of coal is mined with a high-powered cutting system and the coal is transported out of the mine through a network of conveyors. The method is a "caving" method and the surface above the "gob" or mined areas ...
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 …
To explore a realistic top coal caving interval of the longwall top coal caving working face, longwall top coal caving panel 8202 in the Tongxin Coal Mine is used as an example, and 30 numerical ...
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 ...
Two longwall faces are again developed. The top slice is placed so that there is 5m of coal left above the supports. This top slice is advanced as an ordinary longwall operation, leaving 5m of coal overhead. The overhead coal is allowed to cave with the roof and so, is preliminarily broken. A second longwall face is then started off …
The optimization of top coal caving technology is an efficient method to improve the recovery ratio in longwall top coal caving (LTCC). In extrathick coal seams, the conventional single-opening ...
The paper discusses advanced top coal caving technologies for thick coal seams and addresses some issues of incomplete coal extraction, which can result in the environmental …
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, …
Longwall top coal caving (LTCC) is a relatively new method of mining thick coal seams that is currently achieving high productivity and efficiency in application, particularly in China.
The optimization of top coal caving technology is an efficient method to improve the recovery ratio in longwall top coal caving (LTCC). In extrathick coal seams, the conventional single-opening sequential caving technology (SOSCT) shows the following problems: low recovery ratio, high rock mixed ratio, and poor drawing balance. For these …
In longwall top-coal caving (LTCC) mining, progressive failure process of top coal is closely related to the mining-induced stress. In order to achieve failure mechanisms of the top coal, stress distribution of the LTCC face adjacent to the gob is analysed in this study with field investigation and numerical simulation.
They developed a CDEM model that included coal strata, working face conveyor, and hydraulic support. Their analysis focused on the mechanism of top coal …
The longwall top coal caving (LTCC) is the main method to extract thick and extrathick coal seams. Figure 1 shows the basic procedure of LTCC. A longwall …
The authors perform numerical modeling for the comprehensive stress-strain analysis of roof rocks above powered roof support units in the longwall top coal caving technology. Passive control of top coal prefracture fails to maintain efficient disintegration and well-proportioned flow feed on armoured face conveyor. The relations between the …
Please cite this article as: G. Feng and P. Wang, Simulation of recovery of upper remnant coal pillar while mining the ultra-close lower panel using longwall top coal caving, International Journal ...
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 …
The optimization of top coal caving technology is an efficient method to improve the recovery ratio in longwall top coal caving (LTCC). In extrathick coal seams, the conventional single-opening ...
Layered mining has the problem of high requirements for roadway layout, and roadway support is relatively difficult [5][6][7]. Top coal caving technology has the advantage of high mining ...
Longwall Top Coal Caving (LTCC) is a modified longwall mining method for efficient extraction of the thick coal seams. The major difference between LTCC and the traditional longwall method is the extraction of the caved coal from behind the shields as well as the sheared face (Fig. 1).The method has been widely implemented by the …
This paper presents a new criterion for assessing top coal cavability in Longwall Top Coal Caving mining technology. Top coal Cavability Index (TCI) criterion was developed through a parametric ...
Not all the coal would be recovered, but recoveries of 75-80% of the full seam in the block are achievable. The system also allows the initial mining height to be reduced to a preferred working height without losing coal. The Top Coal Caving is a Modified Longwall Mining system. Equipment Selection of Longwall Top Coal Caving Mining
If ultra-close coal seams are mined at a great mining height at one time, for instance, using longwall top coal caving (LTCC)–a longwall mining method that is widely used in China for mining of ultra-thick coal seams, then the locations and characteristics of the bands would have a significant influence on the success of their extraction ...
1. Introduction. Longwall Top Coal Caving (LTCC) is an underground mining method developed for thick seam extraction. Depending on the coal seam condition various layouts can be considered for the LTCC [1].The full seam height LTCC mining layout has been chosen for this work as it takes full advantage of support pressure in …
Longwall top coal caving (LTCC) mining technologies with roof softening by hydraulic fracturing method. V Klishin 1, S Nikitenko 1 and G Opruk 1. ... The paper discusses advanced top coal caving technologies for thick coal seams and addresses some issues of incomplete coal extraction, which can result in the environmental …
In the longwall top coal caving method applied in steeply inclined thick coal seams, top coal loss zone is formed above the tail part of the face depending on the coal seam slope and the top coal ...
The top-coal caving longwall mining was successfully put on trials in Yangquan Mining Bureau in 1988 and Lu'an Mining Bureau in 1989. At the same time, research on the top-coal caving mining in steeply inclined thick coal seams began with good results [5]. ... International Journal of Mining Science and Technology, Volume …
Abstract—Longwall Top Coal Caving (LTCC), a relatively newer technology in India, is an underground mining method developed for thick seam extraction. Various factors and systematic approaches ...
Since its introduction in 1982, fully mechanized top coal caving mining technology has emerged as the primary mining method in China for thick and extra-thick coal seams. It has undergone years of testing, promotion, application, and development, and is widely utilized primarily in mining regions mainly in Inner Mongolia, Shaanxi, and …
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 production in single mining panels. To address these problems, a novel non-pillar coal mining technology in LTCC was used based on the …
Longwall top coal caving (LTCC) is a special type of mining method commonly used to extract coal seams thicker than 4.5 m (Wang et al. 2018a).This method originated in France and Eastern Europe in the 1950s for extracting coal pillars from marginal areas of coalfields (Wang et al. 2014).LTCC is mainly used in China these …
Longwall Top Coal Caving. 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 …
DOI: 10.1080/15567036.2020.1841339 Corpus ID: 228845044; Feasibility study on fully mechanized large mining height long wall top-coal caving mining in ultra-thick (20–30 m), parting-rich coal seams: A case …
Mechanized longwall mining requires heavy machinery and equipment that are shearer for coal cutting, hydraulic shields for roof control, and armored face …
Associate Professor, Coal Industry Engineering Research Center of Top Coal Caving Mining, China Univ. of Mining and Technology, D11 Xueyuan Rd., Haidian District, Beijing 100083, China. Email: [email protected]
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 gained a lot of achievements and experience not only in caving technology and equipment but also in the drawing theory after 40 years of …