中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 24 No. 12 December 2014 |
（1. Institute of Inorganic Chemistry, Slovak Academy of Sciences,
Dúbravská cesta 9, SK–84536 Bratislava, Slovakia;
2. Institute of Inorganic Chemistry, Technology and Materials, Slovak University of Technology,
Radlinskeho 9, SK–81237, Bratislava, Slovakia;
3. School of Materials and Metallurgy, Northeastern University, Shenyang 110819, China）
Abstract:Electrical conductivity of molten binary and ternary mixtures based on the system NaF-AlF3-SiO2 was investigated by means of a tube–cell (made of pyrolytic boron nitride) with stationary electrodes. Viscosity of the binary system Na3AlF6-SiO2 was measured by computerized torsion pendulum method. It was found that conductivity and viscosity varied linearly with temperature in all investigated mixtures. Obtained content dependence of electrical conductivity (isotherms) was divided into two parts. First, one represented the content region up to 10% (mole fraction) of SiO2; second, the region was with a higher content of SiO2 (from 10% up to 40%). While the conductivity considerably decreased with content of SiO2 in the second part; it surprisingly rose in the low content range. A small addition of SiO2 to the molten cryolite (up to 10%) could slightly increase viscosity, but had no influence on the slope of this dependence since it is responsible for a glassy-networks formation in the melt. Further addition of SiO2 to the molten cryolite had a huge effect on the viscosity.
Key words: electrical conductivity; viscosity; solar grade silicon; molten salts; molten cryolite–silica melts
