The Encyclopedia Americana, Volume 7Grolier, 1988 - Encyclopedias and dictionaries |
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Page 133
... coal seams as low as 30 inches or to make bottom cuts ranging from 93 % inches be- low the floor to 21 inches above . Each of the driving wheels has a separate transmission . COAL : 2. Kinds of Coal ANALYTICAL DATA FOR VARIOUS. COAL ...
... coal seams as low as 30 inches or to make bottom cuts ranging from 93 % inches be- low the floor to 21 inches above . Each of the driving wheels has a separate transmission . COAL : 2. Kinds of Coal ANALYTICAL DATA FOR VARIOUS. COAL ...
Page 137
COAL : 4. Coal Mining and Production COAL MINING PROCEDURES COAL : 4. Coal Mining and Production LONGWALL MINING TECHNIQUE. RECOVERABLE COAL RESOURCES ( Mapped and explored ) In billion metric tons Percent of world total Soviet Union ...
COAL : 4. Coal Mining and Production COAL MINING PROCEDURES COAL : 4. Coal Mining and Production LONGWALL MINING TECHNIQUE. RECOVERABLE COAL RESOURCES ( Mapped and explored ) In billion metric tons Percent of world total Soviet Union ...
Page 142
... coal mines have also at- tempted extreme economies in fuel deliveries to serve electricity customers . In Britain , 6 miles ( about 10 km ) of interlocked underground con- veyor belts deliver coal from four mines to a generating plant ...
... coal mines have also at- tempted extreme economies in fuel deliveries to serve electricity customers . In Britain , 6 miles ( about 10 km ) of interlocked underground con- veyor belts deliver coal from four mines to a generating plant ...
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