On the Aqueous Recovery of Zinc from Dust and Slags of the Iron and Steel Production Technologies

Abstract

Recently the iron and steel makers as well are much more concerned with the by-products and waste streams generated in their ferrous metallurgical industries. In general, the relevant minor or trace elements (Si, Mn, P, Al, S, As, Cu, Zn, K, Na, Ti, Cr, V, W etc.) are not concentrated very much in the different slags and dust produced and collected during the subsequent processing steps of iron and steelmaking. However, zinc can be an exception, especially when zinc containing (e.g. hot dip galvanized) steel scraps are recycled in electric arc furnaces (EAF) to produce new unalloyed steels.The paper describes, in short, a few examples of the recovery of some valuable metals from such byproducts, then reviews the major selective leaching processes tested or being applied to reclaim pure zinc compounds or metallic zinc as a by-product of the EAF secondary steel making technology. Based on own laboratory experiments the technical feasibility is also discussed of the selective leachability and removal rate of lead from the residues of the ammonia -ammonium carbonate (AAC) leaching of EAF dust. Secondary leaching of such residues obtained after AAC leaching was performed in laboratory autoclaves equipped with mechanical stirring and used up to 250°C.

Reuse and Recycling of By-Products in the Steel Sector: Recent Achievements Paving the Way to Circular Economy and Industrial Symbiosis in Europe

“…Recovery of zinc from the pre-treatment of coated steel scrap before it is fed to the EAF has also been deeply investigated [28]. Moreover, some examples can be provided about the recovery of valuable metals from by-products [29] as well as the selective leaching processes tested or applied to reclaim pure zinc compounds or metallic zinc from EAF secondary steelmaking [30]. Furthermore, although research towards recycling of the high-zinc fraction of BF sludge is limited, recent studies have been performed in order to incorporate this fraction in self-reducing cold-bonded briquettes and pellets [31] (see some examples in Figure 4).…”

Utilization of ladle slag for soil stabilization

“…Heavy metals such as Mn, Zn, Pb, Cr, and Cu were detected in the LS by XRF. Mn is due to its properties as a deoxidant and a sulphide former in steel smelting process (Peaslee et al 2005), and other heavy metal elements come from a variety of steel scraps used in steelmaking (Jaafar et al 2011;Nyirenda 1991;Varga et al 2016).…”