¦Á-¦Â alumina block is the compact structure formed from ¦Á-Al2O3 and ¦Â-Al2O3 alumina acicula and in a most ideal proportion, it has good erosion resisting and good stability, its feature is that when touching melting glass, it produces little stone or bubble. So, ¦Á-¦Â alumina brick may be widely used to the position of touching melting glass of refiner, and may be used to the upper structure including crown