SYNTHETIC ETTRINGITE, CALCIUM SILICATE COMPACT CONTAINING THE ETTRINGITE AND CALCIUM SILICATE COMPACT

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a synthetic ettringite effective as a bulk density reducing material capable of being lightened without decreasing production efficiency while securing the practically necessary strength and dimensional stability of a calcium silicate compact to be used as a building material and/or a whitening material, a method for producing synthetic ettringite and a calcium silicate compact contg. synthetic ettringite and a calcium silicate compact. SOLUTION: An aq. suspension of calcium hydroxide is added to an aluminum sulfate soln. in 5.8 to 6.2:1 molar ratio of calcium hydroxide to aluminum sulfate and at an addition rate of 0.6mol of calcium hydroxide to one mol of aluminum sulfate per minute while keeping the aluminum sulfate soln. and the suspension of calcium hydroxide at 50-90 deg.C to produce synthetic ettringite. The synthetic ettringite obtained by this method has 50-100μm fiber length or 13.0ml/sec straining rate.