Corrosion resistance of binding and matrix phases in basic checker bricks for the middle regions of glass furnace regenerators

Abstract

Long-time stability of basic checker bricks in the regenerators of glass melting furnaces depends mainly on the choice of their binding phase. By means of thermodynamical calculations and corrosion tests it was looked for corrosion-resistant binding and matrix phases for basic checker bricks for the regenerators of oil- and mixed oil-gas-fired flat and hollow glass melting furnaces. It was demonstrated that for a use in the middle regions of regenerators the binding phase has to withstand the combined attack of Na2SO4 and SO3. The reaction behaviour of a large number of ceramic phases was explained under this aspect. It was shown that MgTiO3 and the solid solution MgAl2O4—Mg2TiO4 possess a high corrosion resistance against SO3 and Na2SO4 comparable with that of magnesium aluminium spinel. With these titanium-containing phases a protective coating can be produced for instance on magnesia grains. This coating prevents a contact of Na2SO4 and SO3 with the periclase and thus its destruction through the forming of sodium magnesium sulphate. MgTiO3 and the solid solution MgAl2O4—Mg2TiO4 may be a suitable binding and matrix phase for magnesia-containing bricks.