Ceramics-Silikáty 21, (3) 201 - 215 (1977)

Corrosion measurements on the Dietzel tank furnace and on rotating bars, and studies of changes at grain boundaries showed that in the system MgO-Cr₂O₃ the resistance to corrosion increases with Cr₂O₃ content, Cr₂O₃ alone exhibiting the highest resistance. In the case of chromemagnesites a significant role is played by dispersion and bond of the chromespinelide phase to the periclase grains, the content of silicates and porosity. In the system, SiO₂-Al₂O₃ the resistance to corrosion increases with Al₂O₃ content and decreasing porosity. No favourable effect of baddeleyite was established in the system ZrSiO₄-Al₂O₃; corundum content and porosity are of decisive significance. With respect to resistance to changes in temperature, availability and price, the exposed furnace parts were lined successfully with fired chromemagnesite of 16-20 % porosity, containing 20 % Cr₂O₃, less than 2.5 % SiO₂, and a finely dispersed chromospinellide phase.