The Electrical Conductivity of Na2O-SiO2-MgO and CaO-SiO2-MgO Melts

The measurements on the electrical conductivity of Na2O-SiO2-MgO and CaO-SiO2-MgO melts have been conducted to find out the behavior of MgO in these systems. The electrical conductivity decreased with increasing MgO content in the Na2O-SiO2 system, but it slightly increased in the CaO-SiO2 system. The electrical conductivity gave a good linear relationship with Na atomic % in the Na2O-SiO2-MgO system and Ca+Mg atomic % in the CaO-SiO2-MgO system. Mg2+ ions contributed to the electrical conductivity in the CaO-SiO2 system to such a degree as shown by Ca2+ ions, whereas it will give no contribution in the Na2O-SiO2 system, probably due to the formation of complex anions. Compared with the viscosity data in the previous paper, the SiO2 equivalent to MgO was calculated, and the structural aspects of Mg2+ in the melt were estimated.