Dipping longwalls in semi-steep seams
Use of high productivity equipment designed for level seams gives encouraging results in the semi-steep seams of the Lorraine Basin. In the Lorraine coal basin, this type of coal seam has been mined by ascending horizontal slices with back filling, using two basic methods: (1) multiple front faces in a stepped pattern using drilling, blasting, and timber support. (2) longwall mining to the rise, which is usable in favorable conditions of seam width and ground stability. This method gives face productivities up to 15 metric tons per manshift. The technical progress that has been made in recent years in the area of support, coal cutting, and coal clearance has allowed the mechanization of steep and semi-steep seams. A new method was started in 1981 at the Simon colliery. A caving longwall mining method is used. The dip of the seam averages 33/sup 0/. A two-entry retreat system was selected. The first longwalls were worked at heights of 3 to 3.5 meters (10 to 11 feet). Most of the equipment is similar to that used for mining flat seams. High performance four-leg, self-advancing chock supports are used. In order to meet certain requirements imposed by the dip, the supports have the following particular features: (1) The shields are positioned close to each other to increase support. Also, to reduce caving dangers, side flaps are mounted on the canopy, the rear shield, and the base. (2) The shields are advanced in a staggered fashion to maintain proper roof support after shearing. (3)Telescopic front shields can be brought down onto the spill plates of the conveyor to isolate the face line from the travel way. This provides extra protection against falling materials while giving access to the face.
- OSTI ID:
- 6514918
- Journal Information:
- World Coal; (United States), Vol. 8:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LONGWALL MINING
INCLINED STRATA
POWERED SUPPORTS
SHEARER LOADERS
REMOTE CONTROL
CHAIN CONVEYORS
COAL MINING
FRANCE
MINING EQUIPMENT
UNDERGROUND MINING
CONTROL
CONVEYORS
CUTTER LOADERS
EQUIPMENT
EUROPE
GEOLOGIC STRATA
GEOLOGIC STRUCTURES
HAULAGE EQUIPMENT
MATERIALS HANDLING EQUIPMENT
MECHANICAL STRUCTURES
MINING
SUPPORTS
WESTERN EUROPE
012000* - Coal
Lignite
& Peat- Mining