The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 28, 1989
Filed:
Mar. 04, 1988
David H Sturgis, Gladstone, OR (US);
William W Kemp, Milwaukie, OR (US);
Precision Castparts Corp., Portland, OR (US);
Abstract
Y.sub.2 O.sub.3 is recovered from investment casting shell molds by introducing used mold materials into a dissolution reactor preferably consisting of a rotating vessel having an interior lining of acid and abrasion resistant material. An acid is combined with the materials in the reactor and agitated for a selected time period. Thereafter, the liquid remaining in the reactor is separated from the residual solids and removed. The liquid contains dissolved Y.sub.2 O.sub.3 which is precipitated, preferably using oxalic acid to produce yttrium oxalate [Y.sub.2 (C.sub.2 O.sub.4).sub.3.9H.sub.2 O]. The Y.sub.2 (C.sub.2 O.sub.4).sub.3.9H.sub.2 O is ultimately removed from the solution and calcined to produce high purity Y.sub.2 O.sub.3.