Precise casting method of ceramic mould of turbine casing, namely critical component of heavy-duty gas turbine

The invention provides a precise casting method of a ceramic mould of a turbine casing, namely a critical component of a heavy-duty gas turbine. The precise casting method comprise the following process steps of: preparing three types of bauxite and quartz powder into a dry material of a sand sleeve, wherein the weight ratio of the bauxite with the particle size of 45 meshes to the bauxite with the particle size of 100 meshes to the bauxite with the particle size of 180 meshes to the quartz powder with the particle size of 180 meshes is equal to 50:25:20:5; adding ethyl silicate hydrolysate into the dry material of the sand sleeve in the ratio of the dry material to the hydrolysate equal to 100g: 6ml; mixing the dry material and the hydrolysate uniformly, and pouring and tamping the mixture in a parent form; after the sand sleeve is dry and hard, de-molding the sand sleeve; mixing zirconium sand powder with the particle size of 350 meshes and ethyl silicate hydrolysate in a ratio of 100g: 25ml to prepare slurry; placing the prepared sand sleeve into the slurry and immediately placing the two on a tray; roasting the sand sleeve at 1400 DEG C for 2-3 hours; and casting the sand sleeve by AOD (Argon Oxygen Decarburization) refining steel liquid, and carrying out heat treatment and finishing on the sand sleeve to obtain the product. According to the precise casting method, the quality of a casting piece of a large-sized air inlet machine casing can be greatly improved, the production cost of the casting piece is reduced, and the production period of the casting piece is shortened.