High-temperature shrinkage suppression in refractory ceramic fiber board using novel surface coating agent

Refractory ceramic fiber (RCF) boards are widely used because their insulating properties allow them to reduce energy consumption during high-temperature industrial processes. However, since conventional RCF boards undergo a linear shrinkage of more than 3% above 1300 °C, furnace lining parts, such as the ceiling, wall, and bottom made of RCF board easily become fragile. In order to suppress the shrinkage of the RCF board above 1300 °C, the RCF board surface was coated with a silica sol containing several types of alumina particles. When a RCF board coated with a silica sol slurry containing 50 mass% alumina platelets was heated at 1400 °C for 8 h, the linear shrinkage of the RCF board decreased from 4.3% to 1.5%. This, in turn, improved the heat resistance of the RCF board up to 1400 °C.