1996 Volume 36 Issue 4 Pages 402-409
CaO-Al2O3-SiO2=50-42-8 wt% eutectic slags, similar in composition to a secondary steelmaking slag, containing different amounts of CaS, were heated between 1673-1873 K. DTA was performed. Samples were characterized by EMP and XRD. Four main phases were present: CaO·Al2O3, 2CaO·Al2O3·SiO2, 2CaO·SiO2 and 23CaO·14Al2O3·CaS or 22CaO·14Al2O3·2CaS products of the reaction of CaS with 12CaO·7Al2O3 at 1349(±21)K. The sulfur phases crystallized first and the rest of the melt followed the well known CaO-Al2O3-SiO2 phase diagram. For comparison, typical ironmaking and steelmaking slags (CaO-Al2O3-SiO2=48-12-40 wt%) were also utilized to study the incorporation of sulfur in their structure. The resulting phases were all glasses with some non-stoichiometry.