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Show THE STORY OF TOOELE r 1 iVrN 1 ! tX NV V v v X v X X , r ' x X X vV x , S S'X x ;w J. yh.x..v.Xfe.,?-.XXXXw-A -X. X- Y " ktaJl & After a lor.a and intricate smelting process at 1 ooele, a trickle of molten lead comes to a standstill and is cast Into 4-ton blocks for shipment to a refinery. (Editor's Note: This is the seventh of a series of eight articles tiUed "The Story of Tooele".) Arriving at ths "high line" above the huge smelting works at the Tooele plant of the International I Smelting and Refining Company are shipments of pay dirt from many mining districts in Utah, Idaho, Colorado, Montana, Nevada, California, Cali-fornia, and Arizona. This Is the ore entrance of the Tooele plant and from here the ore begins it3 trek through the intricate milling I and smelting processes that sep-I sep-I arate the waste from the precious I grains of mineral. The plant consists of a lead-zinc sulphide flotation concentrator, copper concentrator, copper smelter, smelt-er, lead smelter, and stag treatment treat-ment plant. The ores treated consist con-sist mainly of lead, lead-zinc, copper cop-per ores and concentrates, and dry silver and gold ores. A lead-silver oxide flotation concentrator ia not now in operation. All crude ores are first automa- I , tically sampled in a sampling mill, which also does whatever crushing S is necessary for the following 3 metallurgical operations. After j being sampled and crushed the ores k are distributed by belt conveyors II to steel storage bins serving the n lead-zinc concentrator, copper smelter, or lead smelter. J The concentrator consists of two 550-ton units and one 250-ton unit k for the treatment of lead-zinc sul-J sul-J Phide ores. This Is the first con-J con-J centrator, or custom selective flota-; flota-; , tion mill built In Western United a. States, and opened the door for j production of lead-zinc sulphide j ores by western mines. Modern flotation Is a concentration process pro-cess which employs the buoyancy of air bubbles in water to float y mineral particles. Certain reagents , or frothers are added to strengthen the bubbles thus forming a strong Persistent froth similar to soap 8U18. The minerals adhere to thi bubbles while the waste rock does not and settles to the bottom of the flotation cell. Thus the first process pro-cess of winning the mineral from the country rock is begun. Products of the concentrator are a high grade lead concentrate which is treated at the lead smelter; a high iron concentrate treated at either the lead or copper smelter, and a high grade zinc concentrate which is shipped to an electrolytic zinc plant in Montana for smelting. The charge for the lead blast furnace is made up of lead concentrate concen-trate after it has been treated in the sintering plant, and flux. The sintering machines serve the double purpose of removing the excess ex-cess sulphur from the charge and at the same time aggolomerating it into a form suitable for blast furnace fur-nace feed. From the blast furnace bins the various constituents of the charge are weighed and bedded into charge cars so as to obtain the best possible mixture for the furnace. These "charge cars handle 6-ton charges to the furnace. The lead is tapped from the side of the blast furnace into 3-ton ladles in which it is carried by overhead crane system to the drossing plant for final treatment. The drossing plant consists of four 60-ton cast steel kettles and two 120-ton cast steel kettles. The furnace lead is poured into the small kettles in which the heavy dross is removed. After this the drossed lead is pumped into the 120-ton kettles where it is decop-perized decop-perized by means of the addition of sulphur and proper agitation. From the 120-ton kettles the lead is pumped into moulds in which 4-ton blocks are cast. An overhead electric crane transports these blocks of lead to railroad cars and they are shipped to the International Interna-tional Company's refinery at East Chicago for refining. (The eighth article in this series will appear in sthese columns soom) |