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Show Where Does Ore Go? ili . ' ' . - . . " Br::' .. v.? . m -T ;-' - i . - 1 "V United States Smelting Refining and Mining Company Concentrating Mill and Smelter, Midvale, Utah The Miilvale Plant ot the United StateH Smelting Refining and Mining Min-ing Company annually treats thousands thou-sands of tons of lead-zinc milling ores, lead, silver and gold ores and concentrates in the modern and fully equipped flotation mill and smelter. A substantial proportion of this tonnage comes from small Independent mining companies and the balance from the Company's mines. The average person does not realize the complexity of the milling, mill-ing, smelting and refining operations opera-tions necessary to produce refined metals for marketing. Low-grade ores usually are first concentrated for elimination of waste material. High-grade ores usually go direct to the smelter, though in some cases they are concentrated. Lead-zinc Lead-zinc sulphide ore, the major product, pro-duct, is concentrated both to eliminate waste material and to separate the lead and zinc minerals. The concentration is done by the flotation process, the principal , ..''"products produced being lead and zinc concentrates. The weight of ore received Is determined by weighing the railroad rail-road cars before and after unloading. unload-ing. The ore first goes to the sampling department, where an accurate ac-curate and representative small Bample Is automatically taken. The sample thus taken Is ground to very fine powder and divided into parts, one part going to the shipper for assay, another being assayed at the smelter. The assay Information as to metal content and value determines deter-mines whether the ore is to go to the flotation mill or direct to the smelter. The ore to be concentrated Is ground wet at the flotation mill until approximately 65 will pass through a wire mesh screen having 40,000 openings to the square Inch. To this fine ground material are added certain chemicals which will cause the lead mineral particles to float in the froth produced In the flotation machines, while the other minerals sink. This lead mineral froth, or concentrate, as it Is known, is skimmed off the surface of the flotation cells. The residue from the lead flotation cells, after addition of other chemicals, goes to the zinc flotation machines, where the zinc mineral floats in the froth and is skimmed off to make zinc concentrate. Other concentrates concen-trates of lesser importance may be made if circumstances warrant. Though it is never possible to recover all of the metals in an ore. The excess, water is removed from the concentrates by large filters, after which the lead concentrate con-centrate is loaded into cars for shipment to a lead smelter and the zinc concentrate for shipment to a zinc plant. At the lead smelter the concentrates concen-trates and the direct smelting ores are roasted and sintered to produce a porous product for smelting in the blast furnace. This sinter is charged into the blast furnace with coke and fluxes and the entire charge liquefied by the intense heat produced in the furnace. The fluxes must be in proper amounts to give good liquefaction. The lead is reduced re-duced to metallic form and trickles to the bottom of the furnace, collecting col-lecting the gold and silver and most of the other metals in the charge. The waste materials and fluxes form a slag which floats on top of the lead. The metallic lead is drawn off from the bottom of the furnace, given a preliminary refining treatment treat-ment to eliminate some of the impurities, im-purities, and cast into slabs. These slabs of lead, known as lead bullion bul-lion due to its content of gold and silver, are shipped to the lead refinery, where the bullion Is refined re-fined electrolytically for production of high grade lead, gold and silver. This electrolytic refining is similar to the electroplating process with which we are all familiar. The zino concentrates are treated in an electrolytic elec-trolytic zinc plant, producing zino of extremely high purity. The last and a very Important step Is the sale of the refined metals by the Sales Department. Prom the money derived from these sales must be deducted the costs of all of these operations taxes and plant maintenance, no small part of which is for wages. The shipper receives his pay from what i3 left. From this it Is obvious that unduly high costs and high taxes work to the disadvantage of the shipper. |