Experimental study on solid state recovery of metallic resources from EAF dust

Abstract

A new process to recover iron and zinc from electric arc furnace (EAF) dust in a solid state has been developed. It comprises three steps: (1) reduction of dust (,1000uC) using gas reductant with high H 2 or CO content; (2) for the solid product of step (1), wet magnetic separation to separate Fe from gangue; and (3) for the condensed fumes collected in step (1), water washing to remove soluble compounds like KCl and enrich and recover the zinc oxide. The performance of this process indicates that four kinds of resources could be obtained, iron rich materials (TFe592?3%); enriched zinc-rich materials (ZnO583?7%); gangue produced in the wet magnetic separation, which can be used as a building material, and KCl solution. The process is greatly energy saving since it is carried out at low temperature so that sintering would not happen. This means that the iron can be separated directly by physical methods which avoid crushing and grinding.

Separation of ZnO from the Stainless Steelmaking Dust and Graphite Mixture by Microwave Irradiation

“…Therefore the removal of zinc oxide from the dust makes it possible to recycle in stainless steel mill. In recent decades, some methods have been developed to process ZnO-bearing dust [1][2][3][4][5]. The methods can be classified into three groups: physical method, wet process (acid process and alkaline process), pyrogenic process.…”

Separation of P Phase and Fe Phase in High Phosphorus Oolitic Iron Ore by Ultrafine Grinding and Gaseous Reduction in a Rotary Furnace

“…The previous research on metallurgical dusts indicated that, [34] when the particle size is less than 0.01 mm, the reaction kinetic condition between particles and reducing gas in the fixed bed is poor, and the diffusion of the gas passing through the bed void takes a long time (2 hours) for ultrafine particles reduction. In order to improve the kinetic conditions of the gas-solid reaction, the contact area of reducing gas and particles should be increased, so use of fluidization has been considered.…”

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

“…High temperatures and long reaction times required for carbothermal reduction of zinc ferrite have raised the interests in investigation of gaseous reduction techniques for processing EAFD. Several researchers have suggested application of gaseous reducing agents for treatment of EAF dusts [10][11][12][13]16]. In this work, the isothermal reduction of zinc ferrite by hydrogen gas was examined.…”

“…The Waelz kiln process is widely used for recycling of EAF dust. However, new reduction processes have been examined and proved to be effective in treatment of EAFD and obtaining products with lower impurities than the Waelz kiln process [9][10][11][12][13].…”