Thermodynamical computations for removal of alkali halides and lead compounds from electric arc furnace dust

Thermodynamical aspects of a separation process, proposed by the authors for the removal of volatile species from EAF dust, have been studied. Computations have been performed using FACT (Facility for Analysis of Chemical Thermodynamics) software. Different conditions have been considered through calculations of equilibrium state. Effects of different additives, temperature and atmosphere at different total pressure were investigated. It has been shown that removal of alkali halides and lead compounds is possible at temperature as low as 900 ∘C. Oxidizing condition 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. Reduced pressure does not change the thermodynamical conditions of the separation process.