Surface borehole: Unterschied zwischen den Versionen
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===Surface Borehole === | ===Surface Borehole === | ||
Surface Borehole are a connection between the surface and the minig area by a vertikal borehole. | Surface Borehole are a connection between the surface and the minig area by a vertikal borehole. | ||
| + | Most used vertical gob wells are developed from the surface in advance of mining. The usual practice is to drill large-diameter (up to 300 mm) vertical gob wells in advance of mining to within 10 to 30 m above the working coal seam. | ||
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| + | A special kind of surface degassing borehole are used in eastern countries. This borehole with a diameter up to 2000 mm locate in a raodway were the longwall starts. The exhausted gas mixture contins mostly less than 4% CH4. The volume is up to 2000 m3 / min. | ||
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== Boreholes for degassing with more than 25 % CH4 == | == Boreholes for degassing with more than 25 % CH4 == | ||
This typ of boreholes are often used in gassy mines to extract the gas from the roof of the layer. The extracted gas contains | This typ of boreholes are often used in gassy mines to extract the gas from the roof of the layer. The extracted gas contains | ||
Version vom 29. Februar 2012, 11:08 Uhr
Surface Borehole
Surface Borehole are a connection between the surface and the minig area by a vertikal borehole. Most used vertical gob wells are developed from the surface in advance of mining. The usual practice is to drill large-diameter (up to 300 mm) vertical gob wells in advance of mining to within 10 to 30 m above the working coal seam.
A special kind of surface degassing borehole are used in eastern countries. This borehole with a diameter up to 2000 mm locate in a raodway were the longwall starts. The exhausted gas mixture contins mostly less than 4% CH4. The volume is up to 2000 m3 / min.
Boreholes for degassing with more than 25 % CH4
This typ of boreholes are often used in gassy mines to extract the gas from the roof of the layer. The extracted gas contains
Ventilation Borehole
Ventilation boreholes are a part of ventilation system of the mine.
