Precipitation Behaviour of Chromium in CaO-MgO-SiO₂-Al₂O₃-Cr₂O₃-Fe₂O₃ Slag System

Abstract

Different cooling process, annealing temperature and addition of B2O3were experimented on the CaO-MgO-SiO2-Al2O3-Cr2O3-Fe2O3slag system with an aim to investigate the chromium precipitation behaviour. The solidified slags were characterized by XRD, SEM, EDX and EPMA. It was shown that, under melt-quenching process, chromium was immobilized in amorphous structure in the slag with basicity lower than 1.0 and Cr2O3content less than 4.0 wt%. It was also found that addition of B2O3and higher annealing temperature would be helpful for the precipitation of chromium into spinel solid solution in slag with basicity of 1.5.

Dissolution Kinetics of Synthetic FeCr₂O₄ in CaO–MgO–Al₂O₃–SiO₂ Slag

“…Dawson et al 20) found that at high temperatures, alkali metal fluorides form a eutectic mixture and act as a solvent for spinel components. These fluxes are usually part of the slag, so a suitable slag system will have a positive effect on the dissolution of chromium ore. Liu et al [21][22][23][24][25] studied the influence of slag composition on the dissolution of chromium ore and found that in the range of high basicity (B = 0.8-1.6), the amount of chromium ore dissolved increases with the decrease of slag basicity, and the mass fraction of increasing Al 2 O 3 and MgO will reduce the amount of chromium ore dissolved.…”