SiO2-CaO

FeO - AI2O3 - SiOj FeO - NasO > SiOs FeO - CaO - SiOs NasO - AI2O3 - SiO2 CaO - AI2O3 - SiOj J L... 

CaO—AI2O3—SiO Mg0-Al203-Si02 FeO -Al2O3-SiO2 CaO—MgO—AI2O3... 

The silica membrane was prepared through sol-gel deposition and chemical vapor deposition methods. The porous a-alumina tube (O.D., 5.0 mm I.D., 3.5 mm length, 300 mm), supplied by Nano Pore Materials Co. Ltd., Korea, was used as a support. The mean pore size and porosity of the support tube were 0.1 pm and 35%, respectively. Tlie effective length of membrane was 100-150 mm at the middle of the tube, and both edges were glazed with a SiO2-BaO-CaO sealant (Nippon Electric Glass, GA-13), and then calcined at 1200°C. 

As the temperatures are reduced, solid phases will crystallize from the melt. The Watt and Fereday correlations do not apply to this region. The studies reported here include the temperature region in which crystals can be expected to form. The authors did not find literature references to phase equilibria studies for the Si02"Al203-Ca0-Mg0-Fe0 or SiO2 Al2O3-CaO-MgO systems in the composition region of interest. As a result some speculation on behavior is involved in any extensive interpretation of the data. 

CaO-Al2O3-SiO2 > Na2O"Al2O3-SiO2. The chemical... 

We have performed analyses of ten of the fifteen binary systems and six of the twenty ternary systems containing the components MgO, FeO, CaO, NagO, AlgOs, and SiO2. (1 8) (Table I)... 

The good correspondence of calculations with the complex concentration dependence of activities in the CaO-FeO-SiO2 system illustrates the fact that our equations properly take into account the kinds of ternary interaction terms known to exist in such systems. (8,9,21) This feature lends confidence in the use of our equations for predictions in multicomponent systems (containing only silica as an acid component) based solely upon the subsidiary binaries. If, as it appears, this is generally true, our method provides an important predictive capability. 

Crystallization of CaO-MgO-Al2O2-SiO2 glasses The results of the crystallization studies of the quaternary glasses have been compiled in Table VII. The liquidus temperature was determined experimentally by extensive series of quenching runs. The temperature of appearance of the secondary and tertiary phase is the highest tanperature at which the respective phase was observed. The phase melilite is a solid solution series between gehlenite and... 

Table VI. Crystallization behaviour observed for the CaO-Al2O2-SiO2 glasses.

Cyclowoll. - cyclowollastonite CaO.SiO2 (high - temperature polymorph)... 

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