The calcined bauxite is used as the raw material that is re-melted and blown into solid ball shape by high temperature spray. It has a highly smooth surface, good air permeability and excellent dispersibility. It can obviously reduce the binder addition for resin coated sand and self-hardening sand. It can greatly save the sand consumption because it can be reclaimed for many times and always in low breakage rate during crushing. Experience has demonstrated around 40-50 times versus 5-10 times for chromite based sands. Ceramsite is used as single sand, no need to mix with other sands. Some foundries can even reclaim them up to 100 times. It is widely used as core sand and facing sand.