METHOD FOR PRODUCING gamma-2CaO. SiO2

摘要

Provided is a method for producing gamma-2Cao. SiO2, which has a high carbonation rate, has a high degree of whiteness, does not comprise any toxic substances, does not inhibit the setting or hardening of cement, has a reduced energy cost during calcination, and has a high yield. The raw mixture is a combination of the raw materials of slaked lime, which is produced as a by-product after producing acetylene by reacting calcium carbide and water, and of silica. In addition, the raw mixture is adjusted so that CaO/SiO2 has a molar ratio of 1.6-2.0 inclusive and a total alkali content of 0.05-1.00 mass%, or so that CaO/SiO2 has a molar ratio greater than 2.0 but not exceeding 2.4, and a total alkali content not exceeding 0.50 mass%. Said raw mixture is calcinated in a rotary kiln at a calcination temperature of 1300-1600ºC to produce gamma-2Cao. SiO2.