Simulation of pyrometallurgical processing of EAF dust bearing nonferrous metals

摘要

Thermodynamic evaluation was carried out for thefuming process of electric arc furnace dust. Dust containing 34percent Fe, 24 percent Zn and 3 percent Pb was chosen forequilibrium calculation. Effects of temperature and amounts ofcarbon, water vapor and participating air on the volatilizationbehavior of zinc, lead and halogens and on the composition of theresultant slag or clinker were examined. It was clarified that Pb andZn remain mostly in the condensed phases under oxidizingconditions, whereas they vaporize as Pb (g), PbS (g), PbCl (g) andZn (g) under reducing conditions. Judged from the results, thetemperature higher than 1,200beg C is required to realize a highrecovery of zinc. By addition of water the decomposition ofhalides is enhanced, but no significant effect is observed forvaporization of Pb and Zn. The condition for metallic iron toprecipitate was shown as a function of temperature and C addition.Matte-making to extract copper, nickel and valuable metals fromthe dust was discussed from thermodynamic point of view.Substantial recoveries of these metals are expected when the matteis produced just before metallic iron precipitation.