China's Refractories

Abstract: Fiber products for microwave kilns were prepared using alumina fibers with alumina contents of 72 mass% and 80 mass%, and calcined alumina powder (4-6 μm) as the main raw materials, silica sol as the binder, and cationic starch as the flocculant. Effects of different raw materials and their additions on the wave transparency of fiber products were researched. The results show that as the alumina fiber (72%) addition increases, the heating rate of the samples first decreases and then increases, and the corresponding wave transparency of the sample first increases and then decreases. When the alumina fibers addition is 40 mass% and the alumina powder addition is 30 mass%, the prepared microwave kiln lining material has a higher mullite content, which improves the wave transparency of the sample. The sample prepared from alumina fibers with an alumina content of 80% has a suitable glass-mullite phase ratio, performs lower overall dielectric constant and good wave transparency, and is a suitable lining material for microwave kilns.

Key words: alumina fibers, microwave kiln, wave transparency