Aluminum Company of America

Carl H Lawhon

Neal Richard Dando

Edward M Anderson

Merle D McRaven

A novel gelation-resistant alumina and process for producing such a product and aqueous slurries composed thereof are disclosed, including grinding aluminum oxide of .alpha.-Al.sub.2 O.sub.3 in the presence of about 0.5 to 3.0 wt. % water. The grinding preferably is performed in a sealed ball mill. Dual phase alumina particles have an aluminum oxide inner core of .alpha.-Al.sub.2 O.sub.3 and an aluminum oxide hydroxide outer phase of .gamma.-AlOOH on the .alpha.-Al.sub.2 O.sub.3, including to a nominal depth, e.g., by way of example, of about 5 to 100 nanometers on the inner core of .alpha.-Al.sub.2 O.sub.3, and having up to 40% higher surface area than the initial aluminum oxide of .alpha.-Al.sub.2 O.sub.3. The novel gelation-resistant alumina can be dispersed in an aqueous slurry having a solids content of 65 wt. % and higher, and the resulting slurry has significantly extended shelf life.

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Benton, AR, United States of America

Carl H Lawhon