Alumina hydrate and its method of preparation

Claim 1

ALUMINA HYDRATE HAVING FROM 1.4 TO 1.6 MOLS OF WATER PER MOL OF AL203, SPECIFIC SURFACE AREA OF ABOUT 300 TO 600 SQUARE METERS PER GRAM, AVERAGE CRYSTALLITE SIZE IN THE RANGE FROM 20 TO ABOUT 40 ANGSTROM UNITS, AND AN X-RAY DIFFRACTION PATTERN WHEREIN THE AREA UNDER THE 28.1*,2$ DIFFRACTION PEAK IS FROM 40 TO 90% OF THE CORRESPONDING AREA FOR STANDARD BOEHMITE, SAID HYDRATE BEING FURTHER CHARACTERIZED BY CAPACITY TO ADSORB WATER VAPOR EVEN AT LOW RELATIVE HUMIDITY AND BY THE EASE WITH WHICH ADSORBED WATER MAY BE DESORBED SIMPLY BY DRYING AT A TEMPERATURE OF 200-220*F.

Claim 3

THE METHOD OF PRODUCING ALUMINA HYDRATE HAVING FROM 1.4 TO 1.6 MOLS OF WATER PER MOL OF AL2O3, AN AVERAGE CRYSTALLITE SIZE IN THE RANGE FROM 20 TO ABOUT 40 ANGSTROM UNITS, AND EXHIBITING AN X-RAY DIFFRACTION PATTERN WHEREIN THE AREA UNDER THE 28.1*, 2$ DIFFRACTION PEAK IS FROM 40% TO 90% OF THE CORRESPONDING AREA FOR BOEHMITE, WHICH COMPRISES THE STEPS OF (A) PRECIPATING AMORPHOUS ALUMINUM HYDROXIDE SUBSTANTIALLY FREE OF CRYSTALLINE ALUMINA HYDRATE BY REACTING ALKALI METAL ALUMINATE SOLUTION HAVING A TOTAL ALKALI CONTENT BELOW ABOUT 200 G.P.L. ALKALI METAL CARBONATE WITH AN LEAST AN APPROXIMATELY STOICHIOMETRIC AMOUNT OF A MINERAL ACID, AT A RATE SUCH THAT THE PRECIPATION OF ALUMINUM HYDROXIDE IS SUBSTANTIALLY COMPLTED BY NEUTRALIZATION INSTEAD OF BY HYDROLYSIS OF THE ALKALI METAL ALUMINATE AT PH BETWEEN ABOUT 10 AND 11 WITHIN A PERIOD OF ABOUT 2-20 MINUTES, WHILE MAINTAINING THE REACTION TEMPERATURE BETWEEN ABOUT 25* AND ABOUT 60*C.; (B) SEPARATING THE PRECIPITATE FROM THE MOTHER LIQUOR, WASHING AND RESLURRYING THE PRECIPITATE IN AN AQUEOUS MEDIUM SO THAT THE PRECIPITATE IS FULLY DISPERSED, WHILE MAINTAINING THE AMORPHOUS CONDITION THEREOFF; AND (C) AGING THE SLURRIED PRECIPITATE AT A PH BETWEEN ABOUT 8 AND ABOUT 9 AT A TEMPERATURE BELOW ABOUT 100*C. FOR A PERIOD BETWEEN ABOUT 5 AND ABOUT 90 MINUTES TO CONVERT THE AMORPHOUS ALUMINUM HYDROXIDE INTO CRYSTALLINE ALUMINA HYDRATE HAVING AFOREMENTIONED CHARACTERISTICS.

Claim 4

THE METHOD OF PRODUCING ALUMINA HYDRATE HAVING FROM 1.4 TO 1.6 MOLS OF WATER PER MOL OF AL2O3, AN AVERAGE CRYSTALLITE SIZE IN THE RANGE FROM 20 TO ABOUT 40 ANGSTROM UNITS, AND EXHIBITING AN X-RAY DIFFRACTION PATTERN WHEREIN THE AREA UNDER THE 28.1*, 2$ DIFFRACTION PEAK IS FROM 40% TO 90% OF THE CORRESPONDING AREA FOR BOEHMITE, WHICH COMPRISES THE STEPS OF (A) PRECIPATING AMORPHOUS ALUMINUM HYDROXIDE SUBSTANTIALLY FREE OF CRYSTALLINE ALUMINA HYDRATE BY REACTING ALKALI METAL ALUMINATE SOLUTION HAVING A TOTAL ALKALI CONTENT BELOW ABOUT 200 G.P.L. ALKALI METAL CARBONATE WITH AN LEAST AN APPROXIMATELY STOICHIOMETRIC AMOUNT OF A MINERAL ACID, AT A RATE SUCH THAT THE PRECIPATION OF ALUMINUM HYDROXIDE IS SUBSTANTIALLY COMPLTED BY NEUTRALIZATION INSTEAD OF BY HYDROLYSIS OF THE ALKALI METAL ALUMINATE AT PH BETWEEN ABOUT 10 AND 11 WITHIN A PERIOD OF ABOUT 2-20 MINUTES, WHILE MAINTAINING THE REACTION TEMPERATURE BETWEEN ABOUT 25* AND ABOUT 60*C.; (B) SEPARATING THE PRECIPITATE FROM THE MOTHER LIQUOR, WASHING AND RESLURRYING THE PRECIPITATE IN AN AQUEOUS MEDIUM SO THAT THE PRECIPITATE IS FULLY DISPERSED, WHILE MAINTAINING THE AMORPHOUS CONDITION THEREOFF; AND (C) AGING THE SLURRIED PRECIPITATE AT A PH BETWEEN ABOUT 8 AND ABOUT 9 AT A TEMPERATURE BELOW ABOUT 100*C. FOR A PERIOD BETWEEN ABOUT 5 AND ABOUT 90 MINUTES TO CONVERT THE AMORPHOUS ALUMINUM HYDROXIDE INTO CRYSTALLINE ALUMINA HYDRATE HAVING AFOREMENTIONED CHARACTERISTICS.