二元系溶融スラツグの電氣傳導度

抄録

In order to study the properties of molten slags, it is one of the most important problems to measure their electrical conductivity, which shows most probably that they consist of several ions,
This paper deals with the electrical conductivity of the systems Na₂O-SiO₂, CaO-SiO₂ and MnO-SiO₂ in molten state.
The specific conductivities (κ) of these systems are of the order of 0.1-1 Ω^-1 cm^-1, and increase with temperature. The conductivity of the system MnO-SiO₂ suddenly decreases in the neighbourhood of the solidifying temperature. At constant temperature the conductivity rises with inrrease of basic oxides. Further logκ is linear, being plotted against 1/T (T: absolute temperature).
Additionally we attempted the electrolysis in the system CaO-SiO₂. The concentration of CaO is larger at positions near the cathode than near the anode. The result indicates that Ca⁺⁺ migrates to the cathode.
The conduction mechanism is ionic, and refering to the specific conductivity of fused salts, it has heen established that molten slags are highly dissociated into ions.
The mechanism of viscosity and electrical conductivity are described on the basis of the model of quasi-crystal. The linear relationship between logκ and 1/T can be shown theoretically. The activation energy of viscosity is greater than of electrical conductivity. This fact indicates that viscosity is mainly controlled by the large silicate ions, while perhaps the conduction by the cations.
The fact that electrical conductivity rises with increase of basic oxides is partly due to the increase of the numher of cations. Further it is also controlled by the mobility of ions.
In the system CaO-SiO₂ the rate of the increase of the conductivity with CaO % decreases at high CaO contents. This may be due to the fact that the strong bonds are formed between Ca⁺⁺ and SiO₄^4-.