Silicate systems

Multicomponent Silicate Systems. Most commercial glasses fall into the category of sihcates containing modifiers and intermediates. Addition of a modifier such as sodium oxide, Na20, to the siUca network alters the stmcture by cleaving the Si—O—Si bonds to form Si—0-Na linkages (see Fig. 3c). 

N. A. Toropov and co-workers. Handbook of Phase Diagrams of Silicate Systems, Vol. II, Israel Program for Scientific Translations, Jemsalem, Israel, 1972. 

We have presented spinel synthesis because these systems were studied first and can be understood in a simple manner. Various silicate systems have also been studied and it has been determined that they are more representative of the general case involving solid state synthesis reactions than spinel. Let us examine the following simple silicate reaction ... 

Reactions Which Occur in the Calcium Silicate System Between Calcium Oxide and Silica... 

Beaudoin, J. J. Feldman, R. F. (1975). Mechanical properties of autoclaved calcium silicate systems. Cement and Concrete Research, 5 (2), 103-18. 

Blundy JD, Dalton JA (2000) Experimental comparison of trace element partitioning between clinopyroxene and melt in carbonate and silicate systems and implications for mantle metasomatism. Contrib Mineral Petrol 139 356-371... 

Another classical example of demixing in the liquid state occurs in the system CaO-Si02 and other binary silicate systems where Si02 is mixed with basic oxides. While the solubility of Si02(l) in the basic oxide is high, there is a... 

Redwine, R.H. and Field, M.B. (1968). The effect of microstructure on the physical properties of glasses in the sodium silicate system. Journal of Materials Science 3 380-388. 

Laser ablation ICP-MS (LA-ICP-MS) was established in the early 1990s as a potential routine tool for the measurement of trace and ultra-trace elements in silicate systems for geology. Early studies (Perkins et al. 1993) used sample preparation techniques identical to that used to prepare rock samples for WDXRF, i.e., either a pressed powder disk or a glass bead fusion method (see Appendix VIII). Such studies concluded that LA-ICP-MS had the potential to surpass XRF in terms of the limits of detection achieved and INAA in terms of the speed of analysis (Perkins et al. 1993 481). It has long been recognized that the main limit on the quantitative performance of LA-ICP-MS is the homogeneity at the trace and ultra-trace level of the solid calibration standards available. Subsequent work (e.g., Hollecher and Ruiz 1995, Norman et al. 1996) has demonstrated that some of the international... 

Table 6.9 also lists the parameters of Richet and Bottinga s (1985) model, which, devised primarily for Al-free melts, accounts for the nonideality of molten silicate systems containing K by introducing an excess term that represents Si-K interactions ... 

Boon J. A. and Fyfe W. S. (1972). The coordination number of ferrous ions in silicate systems. Chem. Geol, 10 287-298. 

Bottinga Y. and Weill D. F. (1970). Densities of liquid silicates systems calculated from partial molar volumes of oxide components. Amer. Jour. Scl, 269 169-182. 

If we assume that alkali activity varies independently of the masses in the silicate system, the activities (more precisely, the chemical potentials) become internal variables of the system where the activity is controlled by potentials or reservoirs outside of the rock observed. 

Ray, I., and Thiele, H., Long Term Leaching of Silicate Systems Testing Procedure, Actinides Behavior and Mechanism, Karlsruhe Report KFK-2456 (1977). 

The preceding discussion shows that both protolytic and dissolution processes in carbonate and silicate systems and redox processes between oxidized and reduced constituents are pH controlling. 

The results of additional experiments conducted with 85Sr and 137Cs spikes are shown in Figure 4. The well known sorption characteristics of bentonite for Sr and Cs ions is apparent (7). The sorption properties of bentonite are reduced at low pH, which is consistent with an electrostatic concept. 137Cs sorption on the iron silicate colloids is considerably less than that observed with bentonite, even though the colloid zeta potentials are similar, which suggests that mechanisms other than simple electrostatic concepts may be involved. Also, the linear trend of data for Sr in iron silicate systems is considered to represent precipitation rather than sorption. 

Shibata, T., Takahashi, E., Matsuda, J. (1998) Solubility of neon, argon, krypton, and xenon in binary and ternary silicate systems A new view on noble gas solubility. Geochim. Cosmochim. Acta, 62, 1241-53. 

Barzakovsky V.P., Lapin V.V., Boykova L.I., Kurtseva N.N., Diagrams of State of Silicate Systems Issue 4. Ternary Oxide Systems. Leningrad Nauka, 1974. 

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