Longwall or Not?
Though a longwall could be operated continuously to complete a block and the product stored on surface, it must be remembered that the coal is paid for when it is mined but does not provide income until sold or used. Storage on the surface is also an additional cost and in some cases coal quality deteriorates when stored in air;
Longwall top coal caving design for thick coal seam in …
coal. The mechanized longwall mining requires flat-lying coal seams, in which the dip of the seam should not be more than 20 . The amount of coal for the production panel must be high enough to cover the initial investment of the mechanized longwall system. Longwall top coal caving (LTCC) is a part of longwall mining that is applicable for
A novel non‐pillar coal mining technology in longwall top coal caving
The roadway formation process of non-pillar coal mining technology in longwall top coal caving panels: (A) the roadway excavation stage, (B) reinforce the support strength of the entry roof and entry rib, (C) split the roof of retained entry, and (D) support the roof and gangue rib of retained entry.
Longwall Mining Overview | Introduction
LONGWALL MINING Overview. In the method of secondary extraction known as longwall mining a relatively long mining face (typically in the range 100 to 300m but may be longer) is created by driving a roadway at right angles between two roadways that form the sides of the longwall block, with one rib of this new roadway forming the longwall face.
A review of cavability evaluation in longwall top coal caving
Longwall Top Coal Caving was initially developed in the former Soviet Union and France in the 1950s and 1960s. It was then applied in the former Yugoslavia, Hungary, Romania, the former Czechoslovakia and Turkey [4], [5], [6].The 'Soutirage' method which was developed in France in the 1960s is considered as the original form …
Critical Aspects of Longwall Top Coal Caving Method for
In case of longwall top, coal caving, the top coal shall fracture, fragment adequately, and cave down onto the rear conveyor immediately after advancing the power supports. ... Indian has extensive underground thick coal reserves of 5–12 m thick suitable for the application of LTCC. There is considerable experience from LTCC mining under ...
A review of cavability evaluation in longwall top coal caving
The underground extraction of the thick coal seam with thickness in excess of 4.5 m is faced with operational, technical, safety and economic problems. Several …
Numerical modelling of anomalous microseismicity influenced …
In a research project completed a few years ago, continuous microseismic monitoring was performed around a working longwall top coal caving (LTCC) panel at Coal Mine Velenje in Slovenia. During a monitoring period of twelve weeks in 2011, a seismic anomaly characterised by a decrease in event counts and an increase in the …
Stress analysis of longwall top coal caving
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. ... Top coal caving is an economical underground mining method, which has recently been introduced, modified and practiced in the underground coal …
Monitoring strata behavior due to multi-slicing top coal caving
For studying the strata behavior due to multi-slicing top coal caving longwall mining along-the-strike direction in steeply dipping extra thick coal seams, the shield support pressures of the upper and lower slices of panel 37220 in Dongxia Coal Mine were monitored using the KJ513 dynamic monitoring system.
The Future | Longwall | underground COAL
Longwall top coal caving has started to be used (at Yancoal Australia Pty Ltd's Austar Mine) and its use is expected to increase in the mid to long term. The main driving …
Longwall Top-Coal Caving: A Productive and …
Longwall Top-Coal Caving isn't just an alternative mining technique; it can be the difference between a productive, profitable mine and an unsustainable operation. The technology reduces waste and operating …
Underground Coal Mining Methods and Their Impact on …
In underground coal mining, the working environment is completely enclosed by the geologic medium, which consists of the coal seam and overlying and underlying strata. ... The longwall top coal caving (LTCC) method was first developed in the 1950s and 1960s in the former Soviet Union and France to increase coal resource …
Analysis of Coal Outlet Parameters by Simulation Modeling of Longwall
Abstract The new design of a powered roof support for the controlled longwall top coal caving in thick coal seams contains a special outlet and a reciprocating feeder. The introduction of such technology needs pre-testing and analysis of the outlet modes per the support units, such that to ensure the maximum allowable fill of the …
Longwall Top Coal Caving (LTCC) technology
Longwall Top Coal Caving (LTCC) technology. LTCC allows the excavation of thick coal seams of 5 to 12 metres at one pass of the longwall machine, generating high productivity and economic returns for an …
(PDF) Thick Coal Seam Mining
The three methods mainly used worldwide in thick coal seams are longwall top coal caving (LTCC), multi-slice longwall (MSL), and, single pass longwall (SPL) methods.
Correction | Avoiding and Correcting Problems | Longwall
AVOIDING AND CORRECTING PROBLEMS d) CORRECTION. face alignment & creep; excessive roof to floor closure; roof failure; equipment not performing correctly
Avoiding and Correcting Problems
top coal caving; automation; cutting methods; avoiding & correcting problems. exploration; preparation; observation; correction. face alignment & creep; ... Such examinations should be carried out for each longwall block, as far in advance of longwall operations as possible, to identify structures (which may or may not extend through the full ...
Critical Aspects of Longwall Top Coal Caving Method for
In case of longwall top, coal caving, the top coal shall fracture, fragment adequately, and cave down onto the rear conveyor immediately after advancing the …
Longwall Top Coal Caving | Introduction | underground COAL
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 …
Cutting Methods | Longwall | underground COAL
Some Half Web systems can provide similar benefits to Pre-cutting, also described in the Longwall section of the Fundamentals of Coal Mining module, but with additional benefits. Depending on the equipment used and the mine's coal haulage capacity, Bi-di mining is often more productive than Uni-di, especially with longer faces, and can handle ...
Investigation of the effect of caving height on the efficiency …
The longwall top coal caving (LTCC) production method, applied by forming a face in the horizontal thickness of the seam and also called horizontal section top coal caving, especially in studies originating from China, is widely used in the production of inclined and thick coal seams.In this production method, in addition to the top coal …
Rockburst and Gas Outburst Forecasting using a Probabilistic …
The changing mining conditions during longwall top coal caving mining (LTCC) were extracted from a coupled numerical model to provide statistically sufficient data for probabilistic analysis. ... Matsui K, Dou LM (2013) Seismic energy distribution and hazard assessment in underground coal mines using statistical energy analysis. Int J …
Investigation of the effect of caving height on the efficiency …
DOI: 10.1016/j.ijrmms.2022.105304 Corpus ID: 254718060; Investigation of the effect of caving height on the efficiency of the longwall top coal caving production method applied in inclined and thick coal seams by physical modeling
3D numerical modeling of longwall mining with top-coal caving
Longwall with top-coal-caving method as applied at Omerler underground mine. 3. Caving mechanism in the top-coal-caving methodUndoubtedly, caving of naturally fractured or blasted top coal under gravity is the most critical factor in determination of mining method-related parameters such as geometry and dimensions …
Case Study on Overburden Fracturing during Longwall Top Coal Caving
Longwall top coal caving (LTCC) is a highly efficient underground mining method that has recently been introduced and modified, and is now being used in underground coal mines in China. The major difference between LTCC and traditional longwall methods is that LTCC extracts caved coal from behind shields as well as from …
Drawing mechanisms for top coal in longwall top coal caving …
Longwall mining is one of the most applicable and effective production methods for underground coalmines. Longwall mining is attractive for producers due to …
Avoiding And Correcting Problems
Roof to floor closure, most commonly measured by measuring clearance between roof or the underside of support canopies and convenient specified locations on longwall equipment (e.g. top of AFC back plates along the face and top of BSL pans or the crusher in the main gate).
Fully mechanized longwall top coal caving technology in …
The paper systematically summarized the main achievements of the fully mechanized longwall top-coal caving technology in passed 20 years in China and the conclusion and understanding on the related issues. The paper provided the issues of the theoretical and technical researches to be strengthened in the next step for the fully mechanized …
Key technologies and equipment for a fully mechanized top-coal caving …
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 …