How does zinc smelting in a blast furnace produce zinc metal?

In the zinc-lead blast furnace, zinc is produced through a pyrometallurgical process that involves the following steps:

• Charging: A mixture of sintered zinc and lead concentrates and metallurgical coke is fed into the top of a sealed shaft furnace.12
• Reduction: Preheated air is blown through tuyeres at the base, burning the coke to generate heat and produce carbon monoxide. This gas reduces the zinc oxide in the charge to zinc vapor.12
• Condensation: The furnace gas, which contains zinc vapor, is directed to a lead-splash condenser. In this chamber, an intense shower of molten lead droplets absorbs the zinc vapor.12
• Separation: The zinc-enriched lead is continuously withdrawn and cooled. As the temperature drops, the lead reaches its saturation point, causing the zinc to separate as a distinct molten layer on the surface. This zinc is then removed as the final product, while the partially cooled lead is returned to the condenser for further use.1

Liquid slag and molten lead are also tapped periodically from the furnace hearth.12