Thermodynamic properties of Na2O-SiO2-CaO melts at 1000 to 1100 °C

Na2O solubility in CaO–MgO–SiO2 melts

“…6 for comparison (EMF measurements in galvanic cells: Neudorf and Elliott, 1980;Yamaguchi et al, 1983;Pak et al, 1989;Kim et al, 2004;Abdelouhab et al, 2008; Knudsen effusion cells mass spectrometry: Zaitsev et al, 1999;gravimetric method: Kawahara, 1984; Ion-Molecule equilibria method: Rudnyi et al, 1988; gas phase equilibration technique: Rego et al, 1985;van Limpt et al, 2006; and chemical equilibration method: Tsukihashi and Sano, 1985;Ivanov et al, 2004).…”

“…Several experimental approaches have been used to measure alkali metal oxide activities in molten silicates at low pressure, including EMF measurements in galvanic cells (Neudorf and Elliott, 1980;Yamaguchi et al, 1983;Pak et al, 1989;Kim et al, 2004;Abdelouhab et al, 2008) or vaporization processes such as Knudsen effusion cell mass spectrometry (Zaitsev et al, 1999;Mueller et al, 2004;Willenborg et al, 2006) and gravimetric method (Steiler, 1976;Kawahara, 1984). These techniques can be very accurate but they require considerable effort for each composition, making it difficult to study a large range of compositions.…”

Thermodynamic optimization of the (Na2O+SiO2+NaF+SiF4) reciprocal system using the Modified Quasichemical Model in the Quadruplet Approximation

“…Two techniques have been favored: Knudsen effusion method [43,[84][85][86][87][88][89][90] and electromotive force measurement (EMF) [91][92][93][94][95][96][97][98][99][100][101][102][103]. Other methods have also been used to obtain Na 2 O activity, such as transpiration methods [104][105][106] and heterogeneous equilibrium methods [107][108][109][110].…”

“…Two authors have performed EMF measurements using a reference melt where the activity of Na 2 O was known. Neudorf and Elliot [98] used a (Na 2 O + WO 3 ) melt as a reference, but the activity for Na 2 O in this melt is based on unpublished work and extrapolated outside the temperature interval where the measurements were made. Nonetheless, the reported data are in relative good agreement with Zaitsev et al [43,44].…”

Control of alkali-metal oxide activity in molten silicates

“…Next to thermodynamic modelling of metal oxide-silica binary melts [1,[6][7][8], several experimental attempts have been made to measure or control alkali-metal oxide activities in molten silicates at low pressure, such as EMF measurements in galvanic cells [9][10][11][12] or vaporization processes such as Knudsen effusion cells mass [13][14][15]. While very accurate, these techniques are however difficult to undertake due to the long-time acquisition experiments.…”