Alkali Corrosion-Resistant Heat Insulation Materials
They contain higher amounts of alkali components than conventional energy carriers and enhance corrosion reactions. This study investigated a new approach based on alkali aluminosilicates which are typical corrosion products of fire clay related heat insulation materials. In the synthesis experiments, three processing routines were investigated: a hydrothermal treatment up to temperatures of 200 °C, a thermal treatment up to temperatures of 1200 °C and a combination of both technics. The phase composition and the alkali corrosion behaviour of the synthesized materials were investigated. The analysis showed that the relation between phase composition and the corrosion behaviour of the synthesized materials were complex.
The stoichiometry of KAlSiO4 yielded a promising material. An appropriate shaping technology was established. The resulting shaped samples were basically characterized with regard to bulk density, porosity, cold crushing strength, thermal conductivity, refractoriness under load. After testing the material under alkali load on a laboratory scale, the material was successfully applied in the heat insulation lining in an industrial furnace.