OCR Text |
Show PYRITIC SMELTING. Wonderful Progress Made in the Furnaces Fur-naces of This State. Pyrltic smelting. In such extensive practice in Salt Lake' valley, differs from the ordinary smelting chiefly In the 'use of iho sulphur in the pyrltc and other sulphides sul-phides present In the charge, as fuel, says tho Mining and Scientific Press of San I'Yanclsco. whereas in the ordinary smelting smelt-ing methods, It Is desirable to have mat ' .: : . . i of Hie ore of the charge oxidized before it enters the furnace.' and the charcoal or coke are employed as fuel, with sometimes some-times wood as auxiliary. Lead and copper cop-per smelting arc similar In many respept, though In copper smelting, matte and not metallic copper Is iiKurtllv produced, but this depends to a great vxtent upon the character of the ore. In lead smelting the ores are reduced to metallic lend, which carries down any precious metals that may be present, and also the copper if any. Hot blast la used In each of these several kinds of smelting, though there appears to bo a disagreement among smellers us to the degree of heat most beneficial to the process. It is claimed that experiments have shown that a very hot blast does not pay in proportion to the expense necessary to raise the heat to a high degree. In some Instances the heat of tho furnace Itself Is eniploved to heat the blast, but II Is not generally the practice, prac-tice, special stoves for heating the air being be-ing employed for the purpose. It Is generally gen-erally the aim of the smelter to have tho gases escaping from the top of the charge at a relatively low heat. The gases from copper furnaces are not Inflammable, but those of Iron furnaces are. and there tho furnace heat Is utilized In an economical manner. The idea of hot blast In copper smelting was borrowed from tho practice of the Iron furnaces, and it has been In use in Europe for many years. The Idea of heating air of tho blast by means of the hot slag from the copper furnaces Is said to be more feasible than the employment employ-ment of furnace gasis for this purpose." |