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Advantages : tons of coal can be taken so it''s faster than other ways Disadvantages: unable to cut material having a compressive strength of more than about 10,000 psi ( MPa ) due to the very large numbers of picks on the head.
2016 Coal Operators'' Conference The University of Wollongong 10 –12 February 2016 509 EFFECT OF PUNCH LONGWALL RETREAT ON HIGHWALL STABILITY Luke Clarkson1 Abstract: Punch longwall mining takes advantage of the final highwall exposure in an open cut coal mine, driving gateroads straight into the targeted coal seam then retreating the longwall back to just
In particularly dusty mines, the amount of dust in the mine atmosphere can be reduced by directing the air to flow in the same direction that the coal is being transported along the longwall face. This system is known as homotropal ventilation. The advantages of this system are: The intake air at the face is cleaner
Apr 30, 2010· Advantages of Longwall Method High Recovery. ... Retreat Longwall Mining Advantages Over Advance Longwall Mining Reserves are "Proven" on Development Gateroads in the "Solid" Gateroad Development is Separate Water Easier to Control Recovering Equipment Easier Easier Ventilation ... Punch Longwall Advantages Step change in cost and ...
Shrinkage stoping is a mining method used for steeply dipping, narrower ore bodies with self supporting walls and ore. It is an overhand mining method that relies on broken ore being left in the stope to be used as the "working floor" and to support the walls.
Apr 27, 2015· Historically speaking, underground mining not only saves the mining area''s original form but also gives the mining company higher revenues. According to, longwall mining, a type of underground mining that utilizes a longwall shearer, accounts for 50 percent of coal mines in the world and is much safer than other methods of coal mining.
Figure opposite shows a general layout of punch longwall mining. The aim of this method is to mine coal form the highwall of an open cut operation, in which the stripping ratio is far outweighs the production cost of coal mined. The method consists of driving a set of headings in to the coal seam from the highwall of an open cut operation.
Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice (typically 12 m thick). The longwall "panel" (the block of coal that is being mined) is typically 34 km long and 250400 m wide. Longwall mining produced 176 million tons of coal in 2007, about 15 percent of total production.
Longwall Retreating TYPES OF LONGWALL MINING 2. Longwall Advance Mining TYPES OF LONGWALL MINING There are two methods used to cut a web of coal from the longwall face The "BiDirectional" (bidi) method The shearer cuts a fresh web of coal each time it traverses up and down the coal face The "UniDirectional" (unidi) method The shearer cuts a ...
Apr 12, 2016· This video provides a basic description of the longwall mining method for extracting coal underground. It includes an explanation of the different products/key components of a longwall mining ...
Dec 05, 2008· PlotMaker Mining Methods Blackout day presentation 5 th December 2008 VENKAT M. Team Lead – Minex, INDIA Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
The longwall method is currently the safest and most productive for mining coal underground. For a longwall face to reach its full potential, stable gate entries must be maintained. Effective pillar design is often the single most important step a longwall operator can take to protect the gate entries.
longwall punch mining or walltowall mining is obvious. There are several clear operating advantages to operating a longwall in this way and where highwalls are available, the best economic decision will generally favor planning a direct approach.
30 Punch MultiSlice Longwall Mining System for Thick Coal Seam under Weak Geological Conditions A new multislice top coal caving mining method based on the concept of punch longwall and top coal caving methods is proposed. The concept of the new
method is the punchlongwall mining method. Enefit Kaevandused AS, one of the major oil shale companies in Estonia, plans to employ this technology in exploiting some of its resources in the near future. This thesis examines the different stability problems related to the planned punchlongwall mining project in Narva oil shale mine.
Oct 23, 2014· Caving Underground Mining Methods (longwall, Sublevel caving, Block caving) 1. This material is intended for use in lectures, presentations and as handouts to students, and is provided in Power point format so as to allow customization for the individual needs of course instructors.
Jun 15, 2018· Longwall method of working consists in laying out long faces (60–200 m long) from which all coal in working section of the coal seam is removed by a series of operations, maintaining a continuous line of advance in one direction and leaving behind...
In coal mining: Origins of longwall mining. The other principal method of modern mining, longwall mining, had been introduced as early as the 17th century and had found general use by the 19th century, but it had long been less productive than roomandpillar mining.
carried out employing longwall methods. According to Hartman and Mutmansky (2002), longwall mining is an exploitation method used in flatlying and tabular deposits, where a long face is established to extract the mineral. In coal longwall mining, large blocks of coal seam (about 300 m wide and 2 to 3 km long) are developed by driving headings,
Shortwall Mining. This method of mining was developed in the late 1960''s to take advantage of the then recent development of suitable hydraulic longwall supports, coupled with the productivity and low capital cost of continuous miners and shuttle cars.
Longwall mining and roomandpillar mining are the two basic methods of mining coal underground, with roomandpillar being the traditional method in the United States. Both methods are well suited to extracting the relatively flat coalbeds (or coal seams) typical of the United States. Although widely used in other countries, longwall mining ...
Sep 06, 2016· Underground Mining is a method of Mining, where the mineral is extracted without removing the top soil and rocks. In this way we do not disturb the surface feature such as forest, agriculture land, rivers and residential areas. The major disadvant...
Longwall mining is a highly mechaniz ed underground mining sys tem for mining coal. It set of longwall mining equipment consists of a coal shear er mounted on convey or operating
Longwall mining and roomandpillar mining are the two basic methods of mining coal underground, with roomandpillar being the traditional method in the United States. Both methods are well suited to extracting the relatively flat coalbeds (or coal seams) typical of the United States. Although widely used in other countries, longwall mining ...
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