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:
Jun. 23, 1981
Filed:
Jan. 22, 1980
Applicant:
Inventor:
Gordon Lever, Kingston, CA;
Assignee:
Alcan Research and Development Limited, Montreal, CA;
Primary Examiner:
Int. Cl.
CPC ...
C01F / ; C01F / ;
U.S. Cl.
CPC ...
423130 ; 423121 ; 423127 ; 23301 ; 2330 / ;
Abstract
Sodium oxalate in supersaturated solution in Bayer spent liquor stabilized by the presence of humic material is precipitated by the treatment with cationic sequestrants which interact with the humic material to give an insoluble product, thus removing it from solution and destabilizing the solution with respect to precipitation of sodium oxalate. Preferred cationic sequestrants are quaternary nitrogen compounds including medium or long chain alkyl groups. Precipitation of sodium oxalate can be expidited by addition of seed crystals and/or addition of sodium oxalate solution which is supersaturated at a temperature higher than that of the spent liquor.