ReMFra – Recovering metals and mineral fraction from steelmaking residues

The second is the RecoDust process for treating fine-grained by-products, including those derived from the basic oxygen furnace (BOF), electric arc furnace (EAF) and the HIsarna process, a smelting reduction technology for ironmaking with a reduced carbon footprint. The primary objective of the RecoDust process is the separation of zinc and iron from fine-grained feedstocks via smelting and reduction in the so-called Flash-Reactor. This paper describes two trials, in which a zinc separation degree of over 98% could be reached with a highly stable pneumatic dosing rate being one important requirement for an efficient process. The specific energy demand is significantly lower than before, thanks to previous optimisations. This also resulted in a significant high zinc separation, from approximately 20% in the feedstock to less than 0.3% in the iron-rich RecoDust slag (RDS), one of the two products from RecoDust (crude zinc oxide dust is the second product stream).