Spinel micro-powder castable for steel ladle and method for preparing prefabricated part from the castable

The invention relates to the technical field of refractory materials, and provides a spinel micro-powder castable for a steel ladle and a method for preparing a prefabricated part from the castable. The spinel micro-powder castable for the steel ladle is prepared from the following components in parts by mass: 25-40 parts of tabular corundum particles, 15-25 parts of white corundum particles, 15-20 parts of fused magnesia-alumina spinel particles, 8-12 parts of white corundum fine powder, 6-10 parts of alpha-Al2O3 micro powder, 3-5 parts of sintered spinel micro powder, 6-7 parts of cement, 1-2 parts of steel fibers and 1-3 parts of additives. Through the sintered spinel micro powder, the castable is more compact, the porosity is reduced, the pore diameter is reduced, and meanwhile, the generation of calcium hexaluminate (CA6) is promoted, so that the matrix structure is optimized. The castable has high normal-temperature strength and high-temperature strength and excellent high-temperature breaking strength,