How does the KIVCET process extract lead from sulfide ore?

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Metallurgy — lead processing A zinc-lead blast furnace and lead-splash condenser. This technology is utilized mainly for producing zinc while managing both lead and zinc from raw materials, a technique that was highly influential in 20th-century smelting.

The KIVCET process is a method of suspension smelting that extracts lead from sulfide ore through reactions occurring between gases and solids.1

The process utilizes a three-part furnace consisting of a reaction shaft, a waste-gas shaft, and an electric furnace, all linked by a common settling hearth. The operation involves the following steps:1

Preparation: Lead-bearing materials and fluxes are proportioned, dried, and mixed.1
Flash Smelting: The mixture is injected into the reaction shaft and ignited by a blast of commercially pure oxygen. This autogenous (fuel-less) process generates heat through the oxidation of the sulfide ore, reaching temperatures of 1,300–1,400 °C (2,375–2,550 °F), which reduces the oxidized materials into metal.1
Separation: The resulting lead bullion and slag collect in the hearth. Zinc vapor is processed in the electric furnace to produce zinc oxide, while sulfurous gases are captured from the waste shaft to produce sulfuric acid.1

This method is noted for producing less flue dust and extending the service life of furnace brickwork compared to other direct smelting techniques.1