Medium alumina grinding balls with diameters ranging from 1mm to 90mm, and lining bricks for mill with various shapes, such as end flat, circle, flake, and other special shape alumina bricks. It is widely used as grinding media in the area of ceramic tile, sanitary ware, industrial ceramic, electronic ceramic, fine refractory, special cement, enamel production, nonmetallic powder processing, chemical engineering, as well as medicine, paint industries for its high wear resistance, high hardness, great density, high grinding efficiency, and unpolluted raw materials characteristics.