Manufacture of calcium silicate insulating products

Claim 1

AN IMPROVED METHOD OF MANUFACTURING GELLED AND MOLDED, LOW DENSITY HYDRATED CALCIUM SILICATE HEAT INSULING BODIES WITH REDUCED SHRINKAGE, SAID METHOD COMPRISING THE STEPS OF: (A) FORMING AN EXPANDED WATER-CONTAINING HYDRATED CALCIUM SILICATE GEL REACTION PRODUCT BY MAINTAINING A DILUTE AQUEOUS SLURRY CONTAINING LIME AND DIATOMACEOUS EARTH SILICA AT TEMPERATURES OF APPROXIMATELY 120 TO 210*F. FOR PERIODS OF APPROXIMATELY 1/2 TO 3 HOURS; (B) CONDOLIDATING AND SHAPING THE WATER-CONTAINING EXPANDED HYDRATED CALCIUM SILICATE GEL REACTION PRODUCT BY MOLDING THE DILUTE AQUEOUS SLURRY FORMING A LOW SOLIDS DENSITY BODY OF EXPANDED HYDRATED CALCIUM SILICATE GEL AND ENTRAINED WATER OF SUBSTANTIALLY FINAL DIMENSIONS; (C) STEAM INDURATING THE CONSOLIDATED AND SHAPED WATER-CONTAINING BODY FURTHER REACTING THE LIME AND DIATOMACEOUS EARTH SILICA REACTANTS AND THEREBY PRODUCING A POROUS, DURABLE HYDRATED CALCIUM SILICATE BONDED MATRIX; AND (D) THE IMPROVEMENT OF REDUCING THE SHRINKAGE OF THE MOLDED HYDRATED CALCIUM SILICATE BODY COMPRISING IN COMBINATION WITH THE FOREGOING STEPS, PROVIDING THE DIATOMACEOUS EARTH SILICA REACTANT IN A RATIO OF FINE DIATOMACEOUS EARTH HAVING SURFACE AREA AVERAGING ABOUT 6.5 TO 10.0 SQUARE METERS PER GRAM AND COARSE DIATOMACEOUS EARTH HAVING A SURFACE AREA AVERAGING ABOUT 4.5 TO 6.0 SQUARE METER PER GRAM IN PROPORTIONS OF FROM APPROXIMATELY 4 PARTS BY WEIGHT OF THE SAID FINE DIATOMACEOUS EARTH TO APPROXIMATELY 3 PARTS BY WEIGHT OF THE SAID COARSE DIATOMACEOUS EARTH RANGING UP TO 0 PARTS BY WEIGHT OF THE SAID FINE DIATOMACEOUS EARTH TO 1 PART BY WEIGHT OF THE SAID COARSE DIATOMACEOUS EARTH.