The Basic Research About The CaO-Al2O3-SiO2 System Containing C12A7

C12A7has a wide range of applications in many fileds such as in the iron and steel metallurgy, alumina production and cement medium because of its good metallurgical physical and chemical properties, alumina leaching performance and hydration properties. In order to make better use of the excellent performance of the C12A7in practice, the research on C12A7is not limited to the CaO-Al2O3binary system,only by taking it into account the multi-component system, it will have practical value and significance.And in all current optimization reports on the CaO-Al2O3-SiO2system did not contain C12A7, so to do the basic research about the CaO-Al2O3-SiO2system obtaining C12A7is to provide a reference for the application of C12A7.CALPHAD is the current advanced technology of research the phase diagram, the CaO-Al2O3system including C12A7and Al2O3-SiO2system and CaO-SiO2system were re-optimized thermodynamically by using the FactSage software package through the Polynomial (Kohler/Toop) modle, which is different from that of the previous. The optimizational phase diagrams and thermodynamic parameters were obtained, these three systems of liquid excess Gibbs free were calculated by using the optimized thermodynamic parameters for the first time.The optimized data laid the foundation for the extrapolation or forecast the CaO-Al2O3-SiO3phase diagram obtaining C12A7with the Polynomial (Kohler/Toop) modle. In addition, the CaO-Al2O3-SiO2phase diagram whether obtaining C12A7or not was calculated by using the model of quasi-chemical theory through the FactSage, the impact of the C12A7on the CaO-Al2O3-SiO2phase diagram was initially explored,the results show that, the C12A7can stability exist in the CaO-Al2O3-SiO2phase diagram, and occupy a certain primary crystal zone, but will decompose at high temperatures.