Method for preparing hydrous zirconium oxide gels and spherules

A method for preparing hydrous zirconium oxide gels comprising the steps of:

• a) forming a homogeneous aqueous broth comprising HMTA, urea, a zirconium metal salt and a nitric acid, wherein the broth is at a temperature from about 0° C. to about 10° C., wherein said broth has.an HMTA concentration in a range from about 0.7 M to about 1.35 M, a urea concentration in a range from about 0.7 M to about 1.35 M, a zirconium metal salt concentration in a range from about 0.48 M to about 0.64 M, and a nitric acid concentration in a range from about 0 M to about 1.2 M, further wherein the broth has a mole ratio of HMTA to zirconium of ≧1 and a mole ratio of urea to zirconium of ≧1;
• b) placing the aqueous broth within a gel-forming operation, wherein the gel-forming operation is at a temperature from about 85° C. to about 95° C.;
• and
• c) maintaining the temperature of the gel-forming operation from 85° C. to about 95° C. to form a hydrous zirconium oxide gel using an internal gelation process.

A method for preparing hydrous zirconium oxide gels comprising the steps of:

• a) forming a homogeneous aqueous broth comprising HMTA, urea, a zirconium metal salt and a nitric acid, wherein the broth is at a temperature from about 0° C. to about 10° C., wherein said broth has an HMTA concentration in a range from about 0.7 M to about 1.4 M, a urea concentration in a range from about 0.7 M to about 1.4 M, a zirconium metal salt concentration in a range from about 0.48 M to about 0.64 M, and a nitric acid concentration in a range from about 0 M to about 1.2 M, further wherein the broth has a mole ratio of HMTA to zirconium of ≧1.3 and a mole ratio of urea to zirconium of ≧1;
• b) placing the aqueous broth within a gel-forming operation, wherein the gel-forming operation is at a temperature from about 75° C. to about 85° C.;
• and
• c) maintaining the temperature of the gel-forming operation from 75° C. to about 85° C. to form a hydrous zirconium oxide gel using an internal gelation process.

A method for preparing hydrous zirconium oxide gels comprising the steps of:

• a) forming a homogeneous aqueous broth comprising HMTA, urea, a zirconium metal salt and a nitric acid, wherein the broth is at a temperature from about 0° C. to about 10° C., wherein said broth has an HMTA concentration in a range from about 0.9 M to about 1.4 M, a urea concentration in a range from about 0.9 M to about 1.4 M, a zirconium metal salt concentration in a range from about 0.48 M to about 0.64 M, and a nitric acid concentration in a range from about 0 M to about 1.2 M, further wherein the broth has a mole ratio of HMTA. to zirconium of ≧0.9 and a mole ratio of urea to zirconium of ≧0.9;
• b) placing the aqueous broth within a gel-forming operation, wherein the gel-forming operation is at a temperature from about 65° C. to about 75° C.;
• and
• c) maintaining the temperature of the gel-forming operation from 65° C. to about 75° C. to form a hydrous zirconium oxide gel using an internal gelation process.

A method for preparing hydrous zirconium oxide gels comprising the steps of:

• a) forming a homogeneous aqueous broth comprising HMTA, urea, a zirconium metal salt and a nitric acid, wherein the broth is at a temperature from about 0° C. to about 10° C., wherein said broth has an HMTA concentration of greater than about 1.1 M to about 1.4 M, a urea concentration of greater than about 1.1 M to about 1.4 M, a zirconium metal salt concentration in a range from about 0.48 M to about 0.64 M, and a nitric acid concentration in a range from about 0 M to about 1.2 M, further wherein the broth has a mole ratio of HMTA to zirconium of ≧1 but less than 1.5 and a mole ratio of urea to zirconium of ≧1;
• b) placing the aqueous broth within a gel-forming operation, wherein the gel-forming operation is at a temperature from about 55° C. to about 65° C.;
• and
• c) maintaining the temperature of the gel-forming operation from 55° C. to about 65° C. to form a hydrous zirconium oxide gel using an internal gelation process.