Information Circular1950 - Mines and mineral resources |
From inside the book
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... drilling ; prospect drifts and crosscuts are driven through promising areas . longest heading has been driven westward toward Nevada Stewart ground from the 700 level . In the spring of 1949 this search will be supplemented by a renewal ...
... drilling ; prospect drifts and crosscuts are driven through promising areas . longest heading has been driven westward toward Nevada Stewart ground from the 700 level . In the spring of 1949 this search will be supplemented by a renewal ...
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... drilling fatter for drifting.or stoping is used . Each face is drilled according to the judgment of the miner ; the round , however , must be effective . Holes are loaded with gelatin dynamite rated 40 percent strength . Mechanical ...
... drilling fatter for drifting.or stoping is used . Each face is drilled according to the judgment of the miner ; the round , however , must be effective . Holes are loaded with gelatin dynamite rated 40 percent strength . Mechanical ...
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... drilling pattern for drifting.or stoping is used . Each face is drilled according to the judgment of the miner ; the round , however , must be effective . Holes are loaded with gelatin dynamite rated 40 percent strength . Mechanical ...
... drilling pattern for drifting.or stoping is used . Each face is drilled according to the judgment of the miner ; the round , however , must be effective . Holes are loaded with gelatin dynamite rated 40 percent strength . Mechanical ...
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... drilled and blasted on both sides of the ore chute . The broken ore falls on lagging laid down before firing ; the ore is scraped into the chute , and the lagging is removed ; when needed , a set of timber is added to the 3 - com ...
... drilled and blasted on both sides of the ore chute . The broken ore falls on lagging laid down before firing ; the ore is scraped into the chute , and the lagging is removed ; when needed , a set of timber is added to the 3 - com ...
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... drilling pattern for drifting or stoping is used . Each face is drilled according to the judgment of the miner ; the round , however , must be effective . Holes are loaded with gelatin dynamite rated 40 percent strength . Mechanical ...
... drilling pattern for drifting or stoping is used . Each face is drilled according to the judgment of the miner ; the round , however , must be effective . Holes are loaded with gelatin dynamite rated 40 percent strength . Mechanical ...
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13 north 37 south anthracite anthracite mines bituminous coal bituminous-coal and lignite blasting blends Bureau of Mines carbon dioxide carbon monoxide cars catalyst cent mines cent circuit coal bed Coal Mine Inspection coal mines coal-mine inspectors coke concentrate conditions and practices cost County cut and fill D.C. Approval drilling dust allaying electric engineers equipment explosions feet Figure fill stoping fire area fiscal year 1949 fuel gas mask gasification Gunnison County haulage high-volatile Highland Surprise holes hydrogen inches installed investigation Joy Manufacturing June 30 lignite lignite mines loading machine main east entry mechanical method mill mineral mines cent mines Mines Information Circular motor operations oxygen Per-No percent Pine Creek Pittsburgh plant Pocahontas portal properties reports respirators rock dust roof support samples seals shaft SHOSHONE COUNTY shrinkage stoping steel surface surface magazine switch synthesis gas tests timber tons Total tunnel Type underground ventilation volts zinc