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. 18, 1991
Filed:
Mar. 30, 1990
Applicant:
Inventors:
Herman J Hittner, Lower Burrell, PA (US);
Quyen C Nguyen, Newburgh, IN (US);
Assignee:
Aluminum Company of America, Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01F / ;
U.S. Cl.
CPC ...
423111 ; 106705 ; 106789 ; 204 67 ; 423115 ; 423130 ; 501 28 ; 501128 ; 501155 ;
Abstract
A process for treating spent potlining from the electrolytic smelting of aluminum in cryolite includes incinerating the potlining to combust carbonaceous material to form an ash at a temperature low enough to maintain low fluorine vapor pressures, admixing siliceous material with the potlining either before of after the ash-forming stage, and heating the ash and siliceous material to form a glassy residue. The residue formed by the process of the present invention produces a spent potlining suitable for landfill characterized by a low leachability of fluorine in water.