Thermodynamical computations for separation of alkali halides and lead oxide from EAF dust

Abstract

Thermodynamical aspects of a separation process, proposed by authors for removal of volatile species from EAF dust, have been studied. Computations have been performed using FACT program. Different conditions have been considered through calculations of equilibrium state. Effects of different additives and temperature have been determined. Final conditions have been investigated for oxidizing and reducing atmosphere, for inert gas and under different total pressure. It has been found that oxidizing atmosphere helps removal of lead in the form of lead oxide, while reducing condition increases zinc loss due to reduction and evaporation. Higher temperature results in higher vapor pressure of volatile species, but not necessarily in higher amount of removal for volatiles at equilibrium condition. Additives studied had little effect on removal condition. Lower total pressure mainly helps with kinetics of separation process and permits lower temperature operation.