The majority of lead concentrates are sulfide-based. The traditional way of treating these materials is to roast them in a sinter machine, in order to obtain fully oxidized agglomerates, which are subsequently reduced in a blast furnace. This has increasingly been replaced by modern direct bath smelting processes (such as the BlueSmelter of SMS group), consisting of a combined roasting and smelting reaction followed by slag reduction. Existing technologies include QSL, KIVCET, Vanyukov, TBRC, TSL, SKS, and OBBF, which produce lead bullion and slag containing low quantities of lead. Recycled lead is produced using either short rotary furnaces or a combination of reverberatory furnace and slag reduction unit.
In addition to the main metal component, all non-ferrous metals concentrates contain various amounts of other metals, as shown in the Metal Wheel.