Cr(VI) formation in ferrochrome-smelter dusts.

Dusts generated during ferrochrome smelting in a pilot-scale DC arc furnace were sampled from the furnace freeboard and from the off-gas handling stream (cyclone and baghouse). The dusts comprise fine-grained feed material (chromite, flux, and reductant); compositionally heterogeneous, glassy micro-spherules, interpreted as gas condensates and/or aerosolized melt droplets; and trace amounts of ferrochrome. Synchrotron-based micro-X-ray-fluorescence and micro-X-ray absorption near-edge structure around the chromium (Cr) K-edge was used to identify the distribution and speciation of Cr in dust particulates from the freeboard and the cyclone.

Steel slag carbonation in a flow-through reactor system: the role of fluid-flux.

Steel production is currently the largest industrial source of atmospheric CO2. As annual steel production continues to grow, the need for effective methods of reducing its carbon footprint increases correspondingly. The carbonation of the calcium-bearing phases in steel slag generated during basic oxygen furnace (BOF) steel production, in particular its major constituent, larnite {Ca2SiO4}, which is a structural analogue of olivine {(MgFe)2SiO4}, the main mineral subjected to natural carbonation in peridotites, offers the potential to offset some of these emissions.

Structures of two new high-pressure forms of AlPO4 by X-ray powder diffraction and NMR spectroscopy.

The crystal structures of two new high-pressure AlPO(4) phases are reported. One phase synthesized at 6 GPa and 1523 K is triclinic (P1) whilst the other phase synthesized at 7 GPa and 1773 K is monoclinic (P2(1)/c). (31)P MAS (magic-angle spinning) NMR suggests three tetrahedral P sites with equal abundance in both phases.