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Shuikoushan Lead Smelting 1.1 Overview of R&D: In 1988, China began negotiations to introduce the QSL lead smelting process; pilot operations started in 1993. Due to various reasons, this process was not successful in China, making it difficult to promote it. In 1985, China’s **Planning Commission** and **Science and Technology Commission** designated the control of pollution from lead smelting as a key research project. It was decided to carry out expanded tests on wet lead smelting at the Shenyang Smelter, and expanded experimental studies on oxygen bottom-blown oxidation-electric furnace reduction smelting at the Shuikoushan Mining Bureau. In 1998, the China Nonferrous Metal Engineering Design and Research Institute took the lead in organizing a joint effort by Chizhou Smelting Plant, Henan Yuguang Gold and Lead Group, Wenzhou Smelting Plant, and Shuikoushan Mining Bureau to fund industrial trials on oxygen bottom-blown melting – blast furnace reduction, which were successful. In 1999, the **Planning Commission** and the **Economic and Trade Commission** approved the use of this process to build a pilot plant with a capacity of 30,000 t/year at the Chizhou Smelting Plant, as well as to carry out technical upgrades for a lead smelting plant with a capacity of 50,000 t/year at the Henan Yuguang Gold and Lead Group. Based on production experience, for the transformation of the traditional sintering-blast furnace lead smelting process currently used in China, the Shuikoushan method represents a viable option that results in less pollution, lower investment costs, and faster benefits. 1.2 The oxidative smelting of lead concentrate in the Shuikoushan lead smelting process is carried out in a horizontal rotary furnace. This bottom-blown furnace has a structure similar to that of a QSL furnace, with the difference being that it has only an oxidation zone and no reduction zone, resulting in a relatively shorter furnace length. After being calculated, proportioned, and granulated into disc form, lead concentrate, lead dust, flux, and a small amount of pulverized coal are fed into the furnace through the air-sealed feeding port located above it. Industrial oxygen is injected into the molten pool from an oxygen lance at the bottom of the furnace. Once inside the molten pool, the oxygen first reacts with the liquid lead to form lead oxide; part of this lead oxide, under intense stirring, reacts with lead sulfide located in the upper part of the molten pool, resulting in the production of crude lead along with the release of SO2. After the primary crude lead and lead oxide slag formed as a by-product of the reaction are separated by sedimentation, the crude lead is discharged via siphoning or directly, while the lead oxide slag is cast into ingots using an ingotting machine and then sent to a blast furnace for reduction melting to produce secondary crude lead. The SO2-containing flue gas exiting the furnace has its waste heat recovered using a waste heat boiler or a vaporization cooler; after dust removal via an electrostatic precipitator, the gas is sent to acid production. The melting process is carried out under slight negative pressure, and the entire flue gas emission system is kept sealed, thereby effectively preventing the escape of flue gas. At the same time, since the mixture is fed into the furnace in a wet, granular form, and effective smoke collection and ventilation measures are employed at the lead and slag discharge ports, the dispersion of lead dust is prevented. Since only oxidation operations are carried out in the blowing furnace. Without the reduction step, the process is greatly simplified. The one-time lead yield in oxygen bottom-blown smelting is related to the grade of the lead ore; the higher the grade, the higher the yield of crude lead obtained in one step. To meet the requirements of reduction in a blast furnace in the subsequent stage, the lead content in the oxide slag should be around 40%, which is slightly lower than that of the raw sintered masses used in traditional lead smelting methods. Accordingly, the yield of crude lead is generally between 35% and 40%, and the crude lead contains sulfur