PROMOTER FOR PRODUCTION OF TOBERMORITE CRYSTAL, PRODUCTION OF CALCIUM SILICATE HYDRATE SLURRY USING THE SAME AND CALCIUM SILICATE HYDRATE SLURRY PRODUCED BY THE SAME METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a promoter for the production of a tobermorite crystal capable of promoting the production of the tobermorite crystal when carrying out a hydrothermal reaction of a calcareous raw material with a crystalline silicic acid raw material by forming the promoter from one or more calcium sulfates of anhydrous gypsum, gypsum hemihydrate and gypsum dihydrate. SOLUTION: This promoter for the production of a tobermorite crystal comprises one or more calcium sulfate crystals selected from anhydrous gypsum, gypsum hemihydrate and gypsum dihydrate. The promoter for the production of the tobermorite crystal formed from one or more calcium sulfates of the anhydrous gypsum, gypsum hemihydrate and gypsum dihydrate is added to an aqueous slurry used for the hydrothermal reaction in a method for carrying out the hydrothermal reaction of the aqueous slurry containing a calcareous raw material and a crystalline silicic acid raw material under a saturated water vapor pressure and producing a calcium silicate hydrate slurry. The amount of the added promoter is preferably 0.5-35wt.% as the outer percentage, based on the total dry solid content and expressed in terms of the calcareous raw material and the crystalline silicic acid raw material. The mixing ratio [Ca/(Si+Al) molar ratio] of the calcareous raw material to the crystalline silicic acid raw material is preferably 0.3-0.8.