Co-utilization of electric arc furnace dust and copper slag for preparing zinc ferrite based on microwave roasting

Abstract

The feasibility of preparing zinc ferrite from high-zinc electric arc furnace (EAF) dust and high-iron copper slag (CS) based on direct microwave roasting of the wastes together was assessed in this study, with a focus on the effect of microwave roasting temperature. According to the permittivity and permeability measurements of the raw materials, in conjunction with thermodynamic and experimental analyses, it was found that increasing temperature facilitated the formation of zinc ferrite. By fixing the Fe/Zn molar ratio of 2.0 and roasting time of 30 min, elevating the temperature from 500 ºC to 700 ºC led to a significant increase of the percentage of acid-insoluble zinc in the form of zinc ferrite from 81.48% to 94.93%. Further increase of the temperature to 900 °C could not evidently promote the formation of zinc ferrite. After removing impurities by dilute HCl solution and nano milling, the zinc ferrite product had a single phase with the purity of 99.9 wt%. It can act as a great adsorbent of heavy metal ions due to its superior adsorption capacities of 87.99 mg/g, 86.51 mg/g, 86.22 mg/g, and 90.32 mg/g for Pb(II), Cr(VI), Cd(II), and Hg(II), respectively, and as a catalyst for removing tetracycline (TC) using peroxymonosulfate (PMS) with the removal efficiency of 78.54% after 40 min under visible light irradiation. This study offers a facile method for co-utilization of EAF dust and CS to produce value-added functional materials.