Zn and Fe Recovery from Electric Arc Furnace Dusts

Abstract

Steel production generates dust containing Zn and Fe that can be recovered under certain conditions. The main objectives of the study were to evaluate the recovery of these elements when added in briquette form to liquid pig iron at a temperature of 1500°C and to chemically and morphologically characterize the Electric Arc Furnace Dust (EAFD). In the dust characterization stage, the following techniques were used: granulometric and chemical analyses, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD). After characterization, the dust was agglomerated in order to form a briquette, then, placed in liquid pig iron. To perform the tests, a vertical laboratory-scale furnace was used that maintained an inert gas flow (argon) within the furnace during the experiments. All melting tests were performed in this device. Alumina crucibles were used. The zinc was reduced, volatilized and collected by a flue placed on top of the furnace. It was possible to achieve FeO reduction values higher than 98%. The new dust collected during the tests contained iron and 68% of zinc on the average.