mechanized technique used to "scrape" coal from a block several hundred feet wide
An automated form of underground coal mining characterized by high recovery and extraction rates, feasible only in relatively flat-lying, thick, and uniform coalbeds. A high-powered cutting machine is passed across the exposed face of coal, shearing away broken coal, which is continuously hauled away by a floor-level conveyor system. Longwall mining extracts all machine-minable coal between the floor and ceiling within a contiguous block of coal, known as a panel, leaving no support pillars within the panel area. Panel dimensions vary over time and with mining conditions but currently average about 900 feet wide (coal face width) and more than 8,000 feet long (the minable extent of the panel, measured in direction of mining). Longwall mining is done under movable roof supports that are advanced as the bed is cut. The roof in the mined-out area is allowed to fall as the mining advances.
A mining technique in which large blocks of coal are removed in a single pass. This technique uses two tunnels which are about 1500 metres long and 250 metres apart and are joined together at the end by a third tunnel. The third tunnel marks the spot where longwall mining starts.
It is a type of mining which is typically found in an underground coal mines. The coal seam is extracted mechanically and the 'hanging wall' is allowed to collapse to fill in the void under controlled conditions. The collapsed 'hanging wall' material is called 'goaf.'
A form of underground mining in which a panel or block of coal, generally at least 700 feet wide and often over one mile long, is completely extracted. The working area is protected by a moveable, powered roof support system.
An underground mining process in which a panel or block of coal is completely extracted.
An underground mining method that can be used at greater depth than room-and-pillar methods. A cutting machine is pulled back and forth across a panel of coal 400 to 800 feet wide, and the broken coal is moved by conveyor belt to the surface. The roof is held up by moveable supports that are advanced as the coal bed is cut away. The roof in the mined-out area is allowed to fall as the mining advances
A mining technique where the coal seam is removed in one operation by means of a long working face or wall. The workings advance in a continuous line which may be several hundred yards in length.
A form of underground coal mining whereby the seam is removed in one operation by means of a mechanical shearer which cuts along a long working face or 'wall', hence the name.
An underground mining method wherein hydraulic supports are used to brace the mine roof while large machines cut and remove the coal from the coal face; once a seam is mined out, the hydraulic supports are removed and the roof is allowed to collapse
One of three major underground coal mining methods currently in use. Employs a steel plow, or rotation drum, which is pulled mechanically back and forth across a face of coal that is usually several hundred feet long. The loosened coal falls onto a conveyor for removal from the mine. Return to the top of the page. MANHOLE : A safety hole constructed in the side of a gangway, tunnel, or slope in which miner can be safe from passing locomotives and car. Also called a refuge hole.
Longwall mining is form of underground coal mining where a long wall (about 250-400 m long typically) of coal is mined in a single slice (typically 1-2 m thick). The longwall "panel" (the block of coal that is being mined) is typically 3-4 km long and 250-400 m wide. The gate road along one side of the block is called the maingate, the road on the other side is called the tailgate.