Word: open-pit
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Nevertheless, International's bright-eyed, nickel-grey-haired President Robert Crooks Stanley announced last month that Frood had begun open-pit mining. By last week, these new operations were fast approaching a fixed-quota yield of 4,000 tons of ore a day. This is low-grade ore, expensive to smelt. But open-pit mining is much cheaper than shaft mining and-more important to smart President Stanley and International's 90,000 stockholders-combination of the two methods will assure an average grade of ore for many a year, will put off the day when even Frood...
...profit 3,000,000 tons annually of low-grade ore, averaging less than 1% copper, from the deepest mine in North America, the famed Conglomerate shaft which has passed a vertical depth of 5,000 ft. Such lean ore had never before been mined so far down. In open-pit mining, which means simply shoveling away a hill of exposed ore (as at Bingham, Utah), lodes down to 8/10 of 1% can be handled profitably. Deep-vein mining entails the cost of tunneling, drilling, blasting, hoisting, ventilating. Mining engineers consider Mr. MacNaughton's achievement remarkable because his deep...
...Calvin Coolidge, apostle of Prosperity, visiting perhaps the greatest single source of Prosperity in the U. S. The low mountains of Itasca and St. Louis counties are, literally, mountains of iron. Near Hibbing, where the earth gives an enormous red yawn, is the Hull-Rust Mine, the largest open-pit iron ore mine in the world...