Foamed cellular body and method of production

Claim 1

AN IMPROVED METHOD OF PRODUCING A FOAMED CELLULAR REFRACTORY BODY FROM FUSIBLE, GLASSY AND CRYSTALLINE, ALKALINE-ALUMINA-SILICATE NATURAL MATERIALS THAT ARE CHARACTERIZED BY VISCOSITIES OF AT LEAST 10**5 POISES AT 1050*C. AND NOT OVER 10**7 POISES AT 1500*C., A LIQUIDUS VISCOSITY GREATER THAN 10**5 POISES AND A LIQUIDUS TEMPERATURE BELOW AN EFFECTIVE CELLULATION TEMPERATURE WITHIN THE RANGE 10501500*C., WHICH COMPRISES INTIMATELY MIXING SUCH A NATURAL MATERAIL WITH CHEMICALLY REACTABLE FOAMING AGENTS THAT ARE ESSENTIALLY OXYGEN STABLE BELOW 1050*C. AND REACT TO PRODUCE A FOAM WHILE THE MATERIAL IS WITHIN A VISCOSITY RANGE OF ABOUT 10**7 TO ABOUT 10**5 POISES, DEPOSITING A LAYER OF THE MIXTURE ON A REFRACTORY BED, CELLULATING THIS LAYER BY HEATING TO A CELLULATING TEMPERATURE SUCH THAT THE VISCOSITY OF THE MATERIAL IS BETWEEN 10**5 AND 10**7 POISES AND HOLDING AT SUCH TEMPERATURE FOR A TIME NOT OVER 16 HOURS TO PRODUCE A DESIRED DEGREE OF CELLULATION, AND COOLING AND ANNEALING THE CELLULATED MASS.