Use of tar pitch as a binding and reductant of BFD waste to produce reactive materials for environmental applications

Abstract

In this work, a new approach is presented for the modification of the hazardous steel industry waste BFD (Blast Furnace Dust) into a versatile material for application in environmental remediation processes. Tar pitch, another waste, was used to agglomerate the very fine (submicrometric) dust particles to produce a compact and robust pelletized material that under simple thermal treatment produces notably reactive reduced Fe phases. SEM, TG/DTA, Mössbauer, XRD, Raman, BET and elemental analyses indicated that the tar/BFD composite (1:1 wt ratio) pellets treated at 400, 600 and 800 °C lead to tar decomposition to form a carbon binding coat concomitant with the reduction of the Fe oxides to produce primarily Fe3O4 (magnetite), FeO (wüstite) and Fe0. Preliminary reactivity studies indicated that these treated composites, especially at 800 °C, are active for the reduction of Cr(VI)aq and for the elimination of textile dye via reduction and the Fenton reaction.