The traditional pyrometallurgical lead smelting process has many problems, such as serious environmental pollution, difficult recovery of sulfur in raw materials, high energy consumption and low production efficiency. Since the 1950s, some countries in the world have competed to study the direct lead smelting process to replace the traditional pyrometallurgical lead smelting process. By the 1990s, industrial production or semi-industrial tests have been carried out by KIVCET-CS, QSL, ISA and flash smelting. The common feature of these direct lead smelting methods is that they do not need to undergo separate sintering and roasting treatment, and basically realize self-heating smelting. The flue gas is easy to produce acid, and the degree of environmental pollution is light. From the perspective of development, it is possible to replace the traditional pyrometallurgical lead smelting method.

Lead extraction, metallurgy, pyrometallurgy and hydrometallurgy are two kinds of methods, the former is widely used in industrial production. The traditional pyrometallurgy method of lead generally includes three links: lead concentrate sintering and roasting, lead smelting, crude lead pyrorefining or (lead electrolytic refining). The blast furnace reduction smelting method is the most widely used traditional lead smelting method. The lead produced by this method accounts for 85% of the total lead production. Lead smelting by blast furnace reduction smelting method is a method of reducing lead oxide to coarse lead with coke as reducing agent. This method requires first sintering and roasting to convert most of PbS in lead sulfide concentrate into PbO, and then sintering and roasting materials into blocks. The crude lead produced by lead smelting also contains a lot of impurities. It needs to be refined by fire refining or electrolytic refining to obtain refined lead that meets the product quality standards and user requirements, and to recover valuable metals in the crude lead. Fire refining of crude lead plays a leading role in today's lead refining.