THE ELECTRICAL CONDUCTIVITY OF MOLTEN SLAGS CONTAINING TITANIUM-OXIDE(II)

FeO-Tio₂ System

Abstract

Amethod suitable to measure electrical conductivity of molten slags in the nitrogen atmosphere at temperature as high as 1450°C, using pure iron as the crucible and the electrode, was described. In order to eliminate leads resistance the "four-terminal method" was applied. By this method the eleCtrical cohductivity of the FeO-TiO₂ system was measured in the temperature range of 1450-1200°C.
The specfic electrical conductilvity was 30-300Ω^-1cm^-1, which was very high as compared with the conductivity of ordinary ionic condgctors. The change of conductivity with temperature in molten state was very small. For the range of high TiO₂ contents in the conductivity-ternperature curve an anomalous change appeared in the neighbourhood of the solidifying temperature, which was peculiar to the slags of high TiO₂-contents.
Though conductivities could not be measured in the continuous range of composition owing to the high melting point, it was shown that the conductivity decreased with increase of TiO₂ in the range of TiO₂ contents less than about 40 mol%, beyond which the conduc-tivity increased with enhancement of TiO₂.
Both FeO and TiO₂ are semi-conductors and a semilar mechanism of semi-conduction might be predominant in the FeO-TiO₂ system. In the range of low TiO₂ contents the high conductivity was ascribed to semi-conduction concerning. Fe ions, while at the high TiO₂ contents the main part in conduction was played by electrons belonging to Ti ions.
The probable forms of ions are presumed to be Fe⁺⁺, Ti⁴⁺ and O^--, contrary to TiO₄^4- and TiO₃^2- as assumed by O.A. Esin etc.