RHEOLOGY AND CONSTITUTION OF THE CAO-SIO2-MGO-CAF2 SYSTEM

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