CaO-SiO

The two calcium silicates pseudowoUastonite, a-Ca3(Si03)3, and dicalcium silicate, a-Ca2Si04, melt congruently at 1544 2°C and 2130 15 °C, respectively. Rankinite, Ca3Si207 (S.C. P2i/a) dissociates at 1460 5°C. The temperature of 

Dicalcium silicate shows equally complex phase relations that are stiU under discussion. According to Niesel and Thormann (1967) and Taylor (1997), a-Ca2Si04 melts at 2130 °C however, cooUng the melt to 1420 5 °C leads reversibly to high 

Recently, an additional dicalcium siUcate phase, K-Ca2Si04 with S.G. P2j/c was identified during the dehydration of hydro thermally synthesized a-Ca2(Si04H)0H at 800°C (Yamazaki and Toraya, 2001). 

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Waseda, Y., and J. M. Toguri (1977). The structure of molten binary silicate systems CaO-SiO, and MgO-SiOj. Metall. Trans. 8B, 563-68. 

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

Continuous casting slags. These slags have the approximate composition (CaO = SiO = 35% Al-O, = 7% Na O 4-15 and CaF 5-8 ). Olusanya - has reported that the absorption coefficients lie in the range (0.5 - 5 cm ) and thus could be appreciable in these slags. Values of were obtained for ten glassy-slags by Tay r and... 

J. W. DObeteiner discoveied many triads of elements and compounds, the combining weight of the central component being the avenge of its partners (e.g. CaO, SiO, BaO. and NiO, CuO, ZnO). 

Fig. 2.27 The section of the system CaO-SiO -MgO-AljOj-Fe Oj showing stable polymorphic phase of CjS after cooling (after [42]) molar ratio Al20j/Fe20j= 1...

In cement chemistry, it is common to write the chemical formula of compounds involved in the calcination and hydration reactions by capital letters corresponding to the abbreviation of oxides. These standard symbols are Hsted in Table 15.2. For instance, the dicalcium silicate or behte can be written C S. Therefore, it is possible to represent cement composition in a ternary phase diagramm C-S-A (i.e., CaO-SiO -Al Oj). But most commercial cement compositions are restricted to the subsystem C-CjA -C S. 

The equilibrium constant calculated from these solubility data agrees reasonably well with that found by Roller and Ervin (23) in a study of the association of silicate ions in the CaO-SiO -HjO system. These authors found at 30 C a value of 1.5 x 10. Thus it is clear that the solubility of silica increases at high pH because of the formation of silicate ion in addition to SKOH) in solution. 

Fig. 4.1-147 MgO, CaO, SiO, BaO. Temperature dependence of the thermal conductivity k of single crystals [1.124]. Dashed lines, k ocT ...

FIGURE 5.12 Phase equilibria and glass formation region in the soda-lime-silica system. (After K. A. Shahid and F. P. Glasser, Phase equilibria in the system Nafi-CaO-SiO, Phys. Chem. Glasses, vol. 12, 1971, p. 50.)... 

Tabic I Starting compositions of the PDMS-CaO-SiO, hybrids with different PDMS and CaO contents [78,79]... 

Table 2 Starting compositions of PDMS-CaO-SiO -TiOj hybrids [81]...

The reaction diagram and characterization of the hydrothermal products obtained from the 0.5, 1.0 and 2.0 CaO/SiO mixtures... 

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