SOLID-STATE PHASES RELATIONSHIP IN THE CAO-SIO2-AL2O3-CAF2-CASO4 SYSTEM

In this paper the effect of CaF2 and CaSO4 on the equilibrium phases i n the CaO-SiO2-Al2O3 system at 1050 degrees C and 1100 degrees C is pr esented. The phase compatibilities in the five components system were obtained by adding increasing amounts of CaF2 to CaO-rich compositions of the CaO-C2S-CA-CaSO4 system. The introduction of an additional com ponent into the quaternary tetrahedron, involves the appearence of sev en quinary compatibilities at 1050 degrees C and five quinary compatib ilities at 1100 degrees C. The quinary volume F, can be observed at 10 50 degrees C as well as 1100 degrees C. It contains C3Sss in equilibri um with CaO-C(12)A(7ss) - fluorellestadite and CaF2. C3Sss is formed i n those compositions in which all the CaSO4 is combined as fluorellest adite and all the Al2O3 as C(12)A(7ss). Besides, some extra CaF2 must exist. For those compositions rich in CaO in wich CaSO4/CaF2<3, Al2O3/ CaF2<7, CaSO4+Al2O3<10CaF(2) and SiO2/CaSO4>1, the formation of C3Sss is produced.