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:
Nov. 15, 1994
Filed:
Jun. 25, 1993
Eric Barrillon, Meylan, FR;
Pierre Personnet, Saint-Jean-de-Maurienne, FR;
Jean-Claude Bontron, Aix-en-Provence, FR;
Aluminium Pechiney, Courbevoie, FR;
Abstract
A process for heat treating spent pot linings from Hall-Heroult electrolytic cells which comprise carbon and silico-aluminous materials impregnated with fluorides. The pot linings are ground to a particle size less than 5 mm, and formed into an intimate mixture with calcium sulfate or calcium sulfate dihydrate having a particle size less than 1 mm. The mixture is injected into the center of a vortex formed by a flow of circulating hot gas at the top part of a reactor at a temperature between 700.degree. and 1100.degree. C., and extracted from the bottom part of the reaction at a temperature between 400.degree. and 750.degree. C. after a contact time of less than 2 seconds.