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Show Utah's Mining Industry Built on Low Grade Ores " y " ' f ' -' ? ( 1 f ';.. " - S j , , . ( Looks like country rock, but it is less than 1 percent copper ore going into huge crusher or "Coffee Grinder" at Magna. All mines contain a varying amount of low grade ore, a term given to that grade which is too low in mineral values to ship. Small mineral values are in the ore, but the cost of producing it is too heavy to meet the mining, milling and smelting charges. The amount of ore in a mine is therefore largely determined by the operating costs encountered in handling it. Labor costs, supply costs, sometimes pumping costs, shipment costs, treatment costs and taxes all enter into the situation. Low grade ore is a problem. In some instances it is necessary to mine the product and store it on the dump, but more often it is left in the mine. When it is piled on the dump it is generally stored separate from the. mine waste in the hope that it may be of value at some future time. Therefore, the higher the cost of operating a mine, the smaller the mineable ore body becomes and the smaller the ore reserves and the smaller the mining industry. In Utah mines have adopted a policy of mining as much low grade as possible, thereby lengthening the life of the enterprise rather than "gutting" the high grade ore for a temporary showing. It becomes a tragedy when low grade ores are left in the ground, because miners can seldom came back and take this ore out. Unless the low-grade is mined with the high-grade the great majority will remain underground forever. Thus much potential wealth is lost to humanitv forever. |