High-performance mullite heat-insulating refractory castable

The invention relates to the field of high temperature resistant lining materials, in particular to a mullite heat-insulating refractory castable. The high-performance mullite heat-insulating refractory castable comprises, by weight, the following components: 65-72% of microporous mullite grains, 9-16% of corundum powder, 7-14% of mullite micro powder, 1-3% of silicon micro powder, 3-6% of aluminamicro powder and 1-3% of calcium aluminate cement. 0.2-0.5% of the above weight of water reducing agent and 0.1-0.4% of the above weight of alkyl benzene sulfonate are added. The high-performance mullite heat-insulating refractory castable uses microporous mullite as a main castable material, and matched with the powder composed of fine powder and micro powder, the microporous mullite is molded through casting by using alkyl benzene sulfonate as a pore-forming agent, the high-performance mullite heat-insulating refractory castable, used as a permanent-layer lining material of the steel ladleof a high-temperature furn