Alumina Insulation Type AL-28/1800 has been developed using a new process wherein precisely controlled raw materials are pyrotechnically treated resulting in compositized fiber/binder microstructure. It exhibits a bulk density of 0.44 g/cc (28 pcf) with a composition of 80% Al2O3, 20% SiO2. At 1800 C, AL-28/1800 exhibits 3% linear shrinkage and a 1700 C sag resistance of 0.2%. Its MOR is 1.82 MPA (264 psi) with a compressive strength of 1.38 MPA (199 psi). The material is produced in a variety of standard flat boards in sizes up to 18 in. x 24 in. x 2 in. (457 mm x 609 mm x 50 mm). It is easily fabricated into custom insulation components and is readily cemented into "butcher block" furnace roofs.