Using fused magnesia and fused magnesia chrome sand as raw materials, through fine ingredients, high-pressure molding, and ultra-high temperature firing, the product has a high combination rate, good particle combination, good high-temperature volume stability, excellent high-temperature strength, and is widely used in RH , AOD, VOD and other external refining devices, as well as smelting furnaces, converting furnaces and refining furnaces for non-ferrous smelting.