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From: Polovoy <de...@si...> - 2009-12-27 11:20:23
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Us acid, we may add, is the predominant smell in a copper-work; but arsenic acid, hydrofluoric acid, and even arseniuretted hydrogen, are not at all unfrequent. 2. _Melting the Calcined Ore._--This is a totally different operation from the last: in place of roasting, it is one of fusion. The calcined ore is put into the furnace much in the same manner as before; a quantity of the slag from a subsequent process is added to assist in the fusion, and the heat |