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US 3,954,659 AGranted
Method of forming stable dispersions of alumina
AssigneePhiladelphia Quartz Company
InventorJames H. O'Brien
Life of this patent
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Abstract
Stable aqueous dispersions of alumina are formed at concentrations of above about 25% Al.sub.2 O.sub.3 by dispersing alumina dried with a strongly acidic solution. Said stable aqueous dispersions of alumina are stable for at least 2.5 months.
Claims3
A method of forming stable dispersions of substantially colloidal alumina at concentrations above about 25% Al.sub.2 O.sub.3 said stable dispersions being stable for at least 2.5 months, in which:
- a. an aqueous hydrochloric acid solution is prepared at a pH of from about 1.0 to 3.0;
- b. colloidal alumina monohydrate is added to said aqueous solution with vigorous mixing, forming a concentration of about 10 to 30% and a dispersion with a pH of about 1.0 to 3.5;
- c. said dispersion is dried at a temperature from about 50.degree.C to 200.degree.C at 0.1 to 1 Atm;
- d. the dried dispersion is crushed and redispersed in water to form a dispersion of above about 25% Al.sub.2 O.sub.3.
1 more element
Dependencies are inferred from the claim text.