Rheology and constitution of the CaO-SiO2-MgO-CaF2 system

A study of the CaO-SiO2-MgO-CaF2 system was undertaken to determine the effect of the various precipitated mineral species on slag theology. Slags prepared included both basic and acid variations. Three mineralogical species were found in the basic slags; merwinite, monticellite and rankinite. Solidification behaviour was influenced by the concentration of each component, with the more basic slags containing more merwinite and monticellite; this resulted in higher solidification temperatures for these melts. The acidic slags examined contained several variations of impure pseudowollastonite as well as impure calcium fluoride. In selected slag mixtures, the fluorspar component was replaced with an alkali-aluminosilicate tailings material to assess its suitability as a fluorspar substitute. The new slag system was slightly more viscous than comparable slags containing fluorspar; however, the shape of the temperature-viscosity profile was more favourable with respect to an industrial environment. Mineralogical phases encountered here were merwinite, monticellite and akermanite, precipitated from a complex calcia-msgnesia-alumino-silicate melt. (C) 1997 Published by Elsevier Science Ltd.