Spray insulating coating for refractory articles

A spray-applied insulating coating has been developed which offers several advantages over refractory ceramic fiber-containing insulating paper for application to refractory shapes. The new coating is easy to apply and cost effective, it eliminates the potential health hazards associated with the use of refractory ceramic fibers, and it provides sufficient insulation for refractory articles in high temperature applications. The coating is a foamed slurry comprised of a lightweight aggregate and a binder phase. Other ingredients impart green, handling strength. This coating, continuous and homogeneous, was originally developed to replace the fiber paper insulation, and the accompanying "cut and paste" application, on submerged entry shrouds and nozzles used in the continuous casting of steel. Other applications are being investigated.