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, …
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 …
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 …
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 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 ...
1. Introduction. 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 fully mechanized mining is arranged at the bottom coal seam, where the coal is cut by the shearer, with transporting out of the panel by the front scraper conveyor.
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 …
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 ...
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 …
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 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 …
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 …
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 ...
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 …
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 …
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 …
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.
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 …
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 …
Mechanized longwall mining requires heavy machinery and equipment that are shearer for coal cutting, hydraulic shields for roof control, and armored face …
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 …
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 …
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 …
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 …
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 …
Combined short cantilever rock beams-articulated rock beams structure and its application in longwall top coal caving mining. Beijing: Coal Industry Press.
View of a reasonable roadway layout in longwall top coal caving: (A) excavate along the floor of the coal seam when using gob-side entry retaining …
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
They developed a CDEM model that included coal strata, working face conveyor, and hydraulic support. Their analysis focused on the mechanism of top coal …