PROCEDIMENTO PER PRODURRE PIOMBO GREZZO A PARTIRE DA MATERIALE CONCENTRATO TIPO SOLFURO

A procedure based on suspension smelting has been developed for producing lead bullion from sulphidic concentrates in which the proportion of iron and of slag-forming substances is low. In the procedure oxygen or oxygen-enriched air is used. The slag containing lead oxide that is formed is in equilibrium with the sulphur-containing but refinable lead bullion. The lead oxide content of the slag may be lowered without increasing the sulphur content of the lead bullion by regulating the temperature, the FeO+CaO/SiO2 ratio and the degree of oxidation. In order that the highest possible amount of the lead contained in the concentrate might be recovered from the settler (3), the quantity of lead compounds in the gas phase is minimized and a hot cyclone is used in the uptake shaft (4) of the smelting furnace.