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:
Dec. 21, 1976
Filed:
Oct. 20, 1975
Lawrence Keith Hudson, Oakmont, PA (US);
Thomas G Swansiger, St. Louis, MO (US);
Aluminum Company of America, Pittsburgh, PA (US);
Abstract
An improved process is provided for the recovery of sodium aluminate crystallized from a digest of caustic and lime with high-silica aluminous materials. The digest solution is concentrated by evaporation and then seeded with Na.sub.2 Al.sub.2 O.sub.4.2.5H.sub.2 O crystals to crystallize alumina from the solution as Na.sub.2 Al.sub.2 O.sub.4.2.5H.sub.2 O. The crystals are then separated from the mother liquor solution by filtration or centrifugation. The crystals are then washed with a solution having a lower caustic content than the mother liquor and an alumina concentration of about 50 grams per liter to remove any mother liquor remaining on the crystals. The sodium aluminate crystals are used as a feed for a subsequent Bayer processing step.