| Description |
The metallurgy of zinc presents a peculiar problem becomes of the feet that zinc volatilizes at 920C, while a temperature of 1075C to 1150C is required to reduce the metal is reduced therefore as a vapor which must then be condensed to liquid form. Since metallic zinc burns in air at temperature as low as 500C and is readily oxidized by a very small amount of carbon dioxide, the condensation of this zinc vapor is no simple matter. Moreover unless the temperature of condensation is regulated within narrow limits, a large part of the of the zinc vapor will condense as very finely divided zinc mixed with oxide, known as blue power, which is generally distilled. Because of the relatively small charges of the retorts, the zin smelters desire ores of a high zinc content as possible, and will not purchase ores which run below about 25% in zinc. |
