zinc blast furnace

The zinc blast furnace, more accurately termed the zinc-lead blast furnace, is a metallurgical process for extracting zinc. Sintered zinc and lead concentrates are mixed with coke and fed into a shaft furnace. Preheated air is blown in, producing a zinc-bearing gas and molten lead, slag, and recoverable copper and silver.1

The zinc vapor is then absorbed into molten lead droplets in a lead-splash condenser. As the lead is cooled, molten zinc separates and is collected. This process can handle a variety of mixed ores and residues, some of which can bypass the initial roasting and sintering steps. While electrolysis is another major zinc production method, the blast furnace offers flexibility with its feed materials. Early attempts at blast furnace zinc production failed due to difficulties in condensing zinc vapor, a problem overcome by the development of the lead-splash condenser.1234