ANALYSIS OF DUST FORMATION IN THE OXYGEN FLASH SMELTING OF LEAD-BEARING FEEDS IN THE KIVCET SMELTER

摘要

Studies on the kinetics of the competitive processes of PbS volatilization and PbS oxidation, as applied to the heat and mass transfer conditions in the flame of the Kivcet furnace, revealed that the rate-determining factor is the supply of heat. Therefore, low yields of fume in the autogenous flash smelting of lead sulphide feeds are noted despite the high volatility of PbS at 1,300-1,400℃. Dust formation in the autogenous flash smelting of Kivcet-smelters does not exceed 5-7%, of which fumes amount to ～80%. Using extra fuel during autogenous smelting involves the mismatch of the sulphide oxidation rate and the release of heat in the flame, and increases the fume yield. This is a major cause of the high dust formation in pilot plant trials. The analysis of dust formation in the Kivcet smelting of oxidized lead feeds in an industrial-scale smelter shows an overall increase of dust formation (up to 10% of the feed), with fumes constituting ～80% of the dust. A pronounced increase of the zinc component of the fumes is also noted.