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Show The Story of Milling and Smelting at Midvale V i ... 1 k t : yX l,' ..., j a ': ;" V ' !, 3 r i ' I v ' ' ' t , - :i l v x N .s,.a-- S s , - ,.- ' , i I fXJ s ss s , Not unlike huge soup bowls, the lead kettles at Midvale, Utah plant represent one of the Inst steps In the production of lead bullion. The "soup" fed Into these huge kettles i molten lead and here Impurities Im-purities are removed before the lead Is cast into anodes. (Editor's No:-: This is the fourth of a i'rit?s of fivo nrticlos on the story of null-ins null-ins Rnif smelting of lid-rinc ore at Midvale. The previous article of this series described briefly flotation of leadline lead-line suphiiie ores. At its Midvale riant United Slates Smeltins Refining and Mining Min-ing company annually treats thousands thou-sands of tens of lead-zinc mi 11 ins; ores in its modern, fully equipped custom flotation mill and additional thousands of tens of siliceous and direct smelt ins ores in its large smelter. A substantial portion of this tonnage comes from numerous independent mining companies in Utah, Arizona, California, Colorado, Idaho, Montana. Oregon and other outside, points. Yes, Midvalo is an important spot on tlio milling and smelting map of the world. The smelter, situated adjacent to the notation mill (discussed in previous .vvticle) (reals concentrates concen-trates from the mill and direct smelting orev from company and custom mines in Utah and out-of-Etnto points. After weighing nnd sampling these materials a-'o plneed into bins to be withdrawn knter for roasting or. sintering. AVeir'ied amounts of certain concentrate, ores, roaster calcines, other materials and fluxes are sintered in order to combine the line materials Into a sinter cake. This sinier cke, together with oxidized lesd ores, lime rock, scrap iron and furnace coko make up a charge for (he blast furnace. Tlio entire charge Is liipialed by the intense heat, of the furnace. The lead trickles through the charge to tlio bottom of the furnace collecting Hie gold and silver and some of the other metals. The molten lead is drawn off into immense im-mense kettles where sumo of tho impurities are eliminated before the lead bullion slabs are cast for shipment ship-ment to the lead refinery. In the refinery tho lead bullion Is refined elect rolytically producing a high grade lead and certain byproducts, by-products, also gold and silver. This electrolytic refining is similar to the well-known electroplating process. (THE FIFTH OF THESE ARTICLES WILL APPEAR SOON.) |