Abstract

Secondary desulphurization slag from integrated carbon steelmaking was investigated to attain information on respective utilization possibilities or effects upon final disposal. Pseudo-total element concentrations were determined during a six-week sampling period with EN 12457-2/12457-3 compliance test recoveries, scanning electron microscopy + X-ray microanalysis (SEM-EDS) and trace element fractionation with supportive X-ray diffraction (XRD) of parallel extraction residues. Only trace elements Cr and V showed significant pseudo-total recoveries with 210 and 1270 mg kg(-1) (d.w.), respectively. 88% of the respective Cr was attained in the residual fraction of the extraction procedure, as a labile H2O-extractable Cr(VI) concentration of 1.6 mg kg(-1) (d.w.) was attained during the EN 12457-2 test. The RSD value of Cr (32%) in the determined pseudo-total contents of weekly subsamples indicated that fluctuation in slag composition can have a significant effect on the trace element contents of the material. In the case of V, 28% (353 mg kg(-1), d.w.) of the respective pseudo-total concentration was recovered in the NH2OHHCl-extractable fraction, in which XRD suggested only the potential dissolution of larnite. A majority of V (i.e., 65%) was recovered in the residual fraction coupled with the potential dissolution of magnetite and merwinite, as recovery in the HOAc-extractable fraction remained below the limit of quantitation. Additional SEM-EDS investigations proved unsuccessful in exclusively identifying potential V association in the slag samples due to overlapping with additional peaks. (C) 2014 Elsevier B.V. All rights reserved.

Keywords

Chemical extraction; Certified reference material; Steel slag; Trace element; Waste

Published in

International Journal of Mineral Processing
2015, Volume: 134, pages: 29-35
Publisher: ELSEVIER SCIENCE BV

UKÄ Subject classification

Other Chemistry Topics


Publication identifier

DOI: https://doi.org/10.1016/j.minpro.2014.11.006

Permanent link to this page (URI)

https://res.slu.se/id/publ/71157