Zn distribution and speciation in zinc-containing steelmaking wastes by synchrotron radiation induced μ-XRF and μ-XANES spectroscopy

Zinc is an important element in steelmaking industry not only for its impact on environment but also for its hazardous influence to steel production. Collecting information about the chemical association of zinc in zinc-containing steelmaking wastes is fundamental for monitoring its behavior during further treatment. In the work presented here, the spatial distribution, and chemical forms of zinc in accumulated particles of zinc-containing steelmaking wastes, including electric arc furnace dust (EAFD) and basic oxygen furnace OG sludge (BOF OG), have been investigated using synchrotron radiation induced μ-XRF and μ-XANES spectroscopy. Results of μ-XRF analysis showed that zinc distributed in two ways. One was shared with iron and its distribution showed a positive correlation with that of iron. The other was accumulated in some well-defined hot spots with high amount and its distribution showed negative correlation with that of iron. For EAFD, results of μ-XANES spectroscopy indicated that zinc was mainly present in the form of ZnFe2O4 within the whole particles no matter the spots with high or low zinc content. Whereas for BOF OG, ZnFe2O4 was the main constituent in well-defined hot spots while in other regions zinc was mainly in the form of zinc carbonate. These results indicated that chemical reaction between zinc and other components occurred during the formation of accumulated OG sludge particles. If the above findings could be confirmed by more systematic investigations, it will provide valuable information for treating and utilizing these metallurgical residues.