In the last two decades, the Outokumpu flash smelting process has become the dominant new technology for copper smelting and has also been applied to the smelting of other metal sulfides. The application of oxygen enrichment and improvements in concentrate burner and furnace design have resulted in ever increasing smelting rates per unit volume of the reaction shaft. This paper examines the rate phenomena taking place in the reaction shaft of the Outokumpu furnace and compares information obtained from a mathematical model of heat and mass transfer rates to results obtained in pilot tests conducted at Pori, Finland, and to actual performance of a number of flash smelters around the world.
