Why must zinc vapor be condensed during zinc smelting?

During the pyrometallurgical smelting of zinc, the reduction of zinc oxide by carbon occurs spontaneously only at temperatures above the metal's boiling point of 907 °C (1,665 °F). Because the process inherently produces zinc in a gaseous state, it must be condensed into a liquid to be collected and recovered as a usable metal.12

Historically, this requirement made zinc production significantly more difficult than that of other common metals, such as lead or iron, which can be obtained directly in molten form. Efficient methods for this condensation, such as the use of a lead-splash condenser to shock-cool furnace gases, were essential for the development of modern blast furnace operations.21