Refractory product and process

Claim 1

A REFRACTORY BODY HAVING A TOTAL POROSITY BETWEEN ABOUT 15% AND 95% AND HAVING A SUBSTANTIALLY CONTINUOUS INTEGRAL SKELETAL STRUCTURE MADE UP OF INTERCONNECTED WALLS WHICH DEFINE CLOSED CELLS, THE WALLS AND INTERCONNECTING MATERIAL BEING COMPOSED OF A DENSE CONTINUUM OF CRYSTALS OF A REFRACTORY MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALPHA-ALUMINA, COMPOUNDS AND SOLID SOLUTIONS OF ALUMINA AND AT LEAST ONE OTHER METAL OXIDE AND SOLID SOLUTIONS OF AT LEAST ONE METAL OXIDE IN SAID COMPOUNDS OF ALUMINA, SAID CRYSTALS HAVING AN AVERAGE DIAMETER OF LESS THAN ABOUT 8 MICRONS AND EXHIBITING A DENSITY FUNCTION OF AT LEAST 0.5, THE WALLS SURROUNDING THE CLOSED CELLS OF THE SKELETAL STRUCTURE HAVING A THICKNESS BETWEEN ABOUT 0.3 MIL AND THE DIAMETER OF THE RESPECTIVE ENCLOSED CELL, AND THE CLOSED CELLS IN THE SKELETAL STRUCTURE EXCLUSIVE OF MICROPORES HAVING AN AVERAGE DIAMETER, WHEN MEASURED IN A PLANE CUT THROUGH THE BODY, BETWEEN ABOUT 1/2 AND 200 MILS, THE SKELETAL STRUCTURE CONTAINING AT LEAST ABOUT 30% BY WEIGHT OF ALUMINA AND THE ALUMINA IN THE SKELETAL STRUCTURE CONSTITUTING AT LEAST ABOUT 19% BY WEIGHT OF THE TOTAL WEIGHT OF THE BODY; SAID REFRACTORY BODY ALSO CONTAINING FROM 0 TO 81% BY WEIGHT FILLER REFRACTORY AND FROM 0 TO 81% BY WEIGHT OF A METAL SELECTED FROM THE GROUP CONSISTING OF ALUMINUM AND ALLOYS OF ALUMINUM IN WHICH THE ALUMINUM IS THE PREDOMINANT CONSTITUENT.