Investigation of Selective Reduction of Iron Oxide in Zinc Ferrite by Carbon and Hydrogen

Abstract

The feasibility of selective reduction of iron oxide in zinc ferrite, which is one of the main components of electric arc furnace dust (EAFD), was examined. Experiments were carried out by using graphite powder or pure hydrogen gas as reducing agents. The carbothermal reduction experiments performed at temperatures between 973 and 1073 K in inert atmosphere indicated that the method was difficult to apply in practice due to slow rates of reaction and vaporization of zinc. Selective reduction of iron oxide in zinc ferrite was achieved by using pure hydrogen gas as the reductant. The iron oxide was reduced to metallic iron, while ZnO remained unreacted in the solid phase. As reaction times were increased at 873 K, ZnO was also reduced and zinc evaporated. The main advantages of H 2 reduction are high reaction rates, low energy requirements, and no CO 2 emissions. The addition of this process prior to the hydrometallurgical techniques for treatment of EAFD could overcome the difficulties for dissolution of zinc ferrite.

Hydrometallurgical Processes for the Recovery of Metals from Steel Industry By-Products: A Critical Review

“…To avoid the unwanted formation of wüstite, it can be reoxidized to magnetite by magnetization roasting in a CO 2 atmosphere, after which the zinc can be extracted from ZnO at a low acid concentration [196]. ZnFe 2 O 4 is decomposed to metallic iron and ZnO by hydrogen gas at 600 °C [197]. The main advantages of this are high reaction rates, low energy requirements, and no CO 2 emissions.…”

Electrocatalytic hydrogenation of p-and o-isomers of nitrobenzoic acid using bimetallic Fe-Ag composites

“…Some metal ferrites, in addition to their direct use as catalysts, serve as sources for preparing nano-and microparticles of bimetallic iron-containing composites, which also have catalytic properties. The scientific papers [18][19][20] describe in more detail the creation of Fe-Cu-and Fe-Zn-composites by thermal reduction of metal ferrites in a hydrogen flow or in an environment of other reducing gases. We have also shown that as a result of the electrochemical reduction of copper (II) ferrite (CuFe2O4) the Fe-Cu composites are formed with various metal contents determined by the temperature of their preliminary heat treatment, and they exhibit high electrocatalytic activity [21].…”

Microwave assisted alkaline roasting-water leaching for the valorisation of goethite sludge from zinc refining process

“…Franklinite is a very stable spinel structure that requires other routes than those above mentioned to liberate Zn for dissolution. Those may include several methods to decompose the franklinite structure or to reduce the iron and the zinc present in the spinel, as illustrated in Table 1 (Güler et al, 2011;Havlik et al, 2004;Kazemi and Sichen, 2016;Kukurugya et al, 2015;Omran et al, 2017;Santos et al, 2015;Turan et al, 2004;Stanforth, 2000a, 2000b;Zang et al, 2016). Amongst these techniques, an effective and selective combination of thermal and hydrometallurgical treatments, composed of preliminary hydrolysis-NaOH roasting-NaOH leaching, was explored by Youcai et al to quantitatively extract zinc from franklinite-bearing EAF dusts (Zhao Stanforth, 2000b, 2000a).…”