Mining Engineers' Handbook, Volume 1Robert Peele, John Adams Church J. Wiley & sons, Incorporated, 1941 |
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Halaman 2-6
... less usual than those named , and the decline of normal components . Sodalite is sometimes very prominent . Biotite and hornblende are not so frequent as pyroxene . Rocks with leucite are known , but are far less common than those with ...
... less usual than those named , and the decline of normal components . Sodalite is sometimes very prominent . Biotite and hornblende are not so frequent as pyroxene . Rocks with leucite are known , but are far less common than those with ...
Halaman 10-34
... less than 0.2 of the cost of a test pit to same depth . To depths of 20 to 30 ft in surface drift , free from water and requiring no timbering , small test pits usually cost less per ft than churn - drill holes . Pits are better under ...
... less than 0.2 of the cost of a test pit to same depth . To depths of 20 to 30 ft in surface drift , free from water and requiring no timbering , small test pits usually cost less per ft than churn - drill holes . Pits are better under ...
Halaman 12-107
... less time required for loading and dumping ; large capacity in shafts of small cross - section ; less labor for dumping at shaft top ; weigh less than combined cage and car . Less dead wt means smaller rope , drums and engine , or ...
... less time required for loading and dumping ; large capacity in shafts of small cross - section ; less labor for dumping at shaft top ; weigh less than combined cage and car . Less dead wt means smaller rope , drums and engine , or ...
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angle Ariz aver bench black powder blasting block bottom broken caps cars caving chalcocite chalcopyrite churn drills chutes coal copper core cost per ft cribbed cross-sec crosscuts crystals Data deposits depth diam driven dynamite excavation explosives face filled stopes floor footwall ft deep ft high ft long ft wide fuse gelatin grizzly ground hammer drills hanging wall haulage level hematite hoisting holes horiz igneous rocks inclined intervals iron jackhammers labor lagging limestone loading magnetite manway Mesabi Range method minerals mining mucking orebody pillars pipe porphyry posts powder pump pyrite pyrrhotite quartz quartzite raises rock rods samples sand schist scraper sets shift shovel shrinkage stopes side sill sinking slice sludge soft sphalerite square-set steel stope stulls sub-level sulphide surface Table thick timber tons top-slicing Total tunnel usually veins ventilation waste width