Behavior of MgO and NiO in Molten Slags

Abstract

Abstract The measurement of electrical conductivity and viscosity of slag containing MgO and/or NiO has been carried out together with spectroscopic investigation of quenched glasses. In the CaO–SiO2–MgO system these measurements revealed that MgO showed the same effect as CaO, whereas MgO was regarded as acidic oxide in more basic melts like Na2O–SiO2 system. In the CaO–SiO2–NiO system, NiO exhibits more basic property than CaO in the lower content region of NiO. As the content of NiO increases, however, this basic property tends to decrease. ESCA spectra of quenched samples revealed the existence of Ni3+ ion in the lower content region of NiO. Far-infrared absorption spectra showed the existence of undissociated NiO in higher NiO content region. The interaction of MgO and NiO in the melt has been studied, and the results indicate that presence of MgO in NiO-bearing slags helps the dissociation of NiO to Ni2+ and O2−.