In the process of lead refining, using a reverberatory furnace to smelt lead slag is a good method. Since there are many impurities to be removed in crude lead refining, about 10% of the lead and most of the valuable metals such as gold, silver, copper, bismuth, etc. are enriched in the intermediate products, which need further treatment to recover the valuable metals. The slag produced from the lead smelting pot contains a large amount of valuable metals. Due to different slag removal methods or slag removal equipment, the slag morphology and composition are quite different. The copper slag obtained by pneumatic slag extraction has a high copper content and is in the form of loose and fine particles, which is suitable for hydrometallurgical treatment; most of the slag removed by other methods is in block form, which is generally suitable for pyrometallurgical treatment.

According to the nature and form of the slag, and taking into account factors such as cost, the coal-fired reverberatory furnace is currently used. It has the advantages of simple structure, convenient operation, easy control, low investment, and can handle powdered materials and block materials. It can also oxidize and refine lead with the help of the oxidizing atmosphere in the furnace and the oxides in the raw materials. It has strong adaptability to raw fuels. When coal, charcoal or coke is added to the furnace, it can also reduce and smelt lead. The disadvantages are high fuel consumption, low thermal utilization rate, low productivity, large flue gas volume, low SO2 concentration, difficult to handle, and environmental pollution.

Through treatment in a reverberatory furnace, lead becomes crude lead, which is required to contain Pb>95%; copper becomes matte, which contains Cu>35% and Pb<6%, without metallic lead; precious metals such as gold and silver are enriched in crude lead and matte for further recovery.