Foam ceramic is a low bulk density (0.25~0.65) g/cm3, high porosity (60~90) industrial ceramic product with three-dimensional network skeleton structure. Because these products have temperature resistance, chemical resistance and interconnected cavities with large specific surface area, they are used in the fields of metal melt filtration, high-temperature flue gas purification, chemical filtration, carrier and photothermal conversion. Foam ceramics are used in filtration of metal melts. Some enterprises have developed into foam ceramic filters in the gating system, from screen purification and straight hole honeycomb ceramic slices purification. The filter products play a significant role in reducing the scrap rate of castings, improving the mechanical properties of castings, prolonging the life of metal cutting tools and reducing the comprehensive cost. I Performance introduction: (1) Filter out the inclusions in the casting, reduce the gas in the casting, reduce the turbulence degree of liquid metal flow filling, reduce the surface defects in the casting, and significantly reduce the scrap rate of the casting. (2) Increase the compressive tightness of castings, enhance the elongation and tensile strength, and improve the surface finish of castings. Improve the fluidity of molten metal and increase the mold filling capacity and feeding capacity of castings. (3) The design of gating system is simplified. The length of the runner is reduced and the process yield of the casting is improved. (4) The machining time and tool damage are reduced, and the machining surface quality of castings is improved. (5) It has high temperature resistant working strength, chemical stability, thermal shock resistance and metal flow impact resistance. There is no slag dropping or cracking during operation, and the filtering quality of molten metal and the stability of chemical composition. (6) It has large metal flow rate and stable flow rate (different from straight hole ceramic filter, its flow rate gradually decreases with the increase of the number of inclusions captured). Its filtering effect. The filtering effect is much higher than that of other filter elements. Even when there are many inclusions in the molten metal, the normal use will not cause the blockage of the filter. (7) It has high chemical stability, is not affected by the acidity and alkalinity of liquid metal, and does not change the chemical composition of liquid metal. (8) It can be used for automatic placement of filters on the production line with high precision.