Microstructural Analysis of Magnesia Bricks Operating under Altered Conditions in the Regenerator Condensation Zone of Glass Melting Furnaces

摘要

Refractory producers need to offer lining solutions tailored to the different operating conditions occurring in glass melting furnaces [1 ]. For example, in the regenerator condensation zone (700-1100 °C) it is necessary to adapt the lining concept to the specific atmosphere resulting from the waste gas composition. For oxidizing conditions, forsteritic-bonded magnesia-zircon checker bricks are a well-proven lining concept providing satisfactory lining performance, while in a reducing atmosphere pure, low-iron magnesia bricks offer the best performance in this temperature range. However, the requirement to fulfil environmental regulations by implementing for example NO_x reduction measures in addition to severe operating problems can significantly change the typical regenerator atmosphere. In such cases, the corrosive load on the lining from waste gases is highly intensified. In this paper an insight into the microstructural changes occurring in brick linings located in the condensation zone when the atmosphere is drastically changed are discussed with examples from post mortem investigations and a laboratory trial.