Determination of the SiO_2 Activity in Melts of the CaO-Al_2O_3-SiO_2 System by High-Temperature Mass Spectrometry

摘要

This paper reports on the results of systematic investigations into the thermodynamic properties of melts lying along the joins with constant SiO_2 contents of 0.5 and 0.6 mole fractions in the CaO-Al_2O_3-SiO_2 system at mole fraction ratios CaO:Al_2O_3 varying from 0.25 to 4.0.The activities of SiO_2 in melts of this system at a temperature of 1905+-10 K are determined by high-temperature mass spectrometry.It is found that,in the concentration range studied,the activity of SiO_2 remains constant at SiO_2 contents of 0.5 and 0.6 mole fractions.