KAlSiO4-based Potassium Aluminosilicates for Alkali Corrosive Environments

Nora Brachhold, Christos G. Aneziris

Institute of Ceramics, Glass and Construction Materials, TU Bergakademie Freiberg, 09599 Freiberg/Germany

Revision 20.06.2014, 01.07.2014

Volume 6, Issue 3, Pages 93 - 98

Abstract

Alkali corrosion of refractory materials is a problem in high temperature aggregates. The problem has increased strongly during the last years due to secondary fuels used as energy carriers. This study presents potential new materials for alkali corrosive conditions. It investigated the synthesis of potassium aluminosilicates of the nominal composition of KAlSiO 4 . Two synthesizing procedures were applied: a pure thermal treatment at 1200 °C and a combined synthesizing procedure consisting of a hydrothermal treatment at 200 °C followed by a sintering step at 1200 °C. Furthermore, the study concentrated on the use of K 2 CO 3 as K 2 O source and compared the results to previous studies based on KOH as K 2 O source. The results showed that the use of K 2 CO 3 yielded the intended target phase, too. The reaction products based on K 2 CO 3 had a phase composition similar to thermally synthesized KOH­based material and were alkali corrosion resistant.

Keywords

alkali corrosion, alkali aluminosilicates, KAlSiO4

References

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