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. 18, 1986
Filed:
Feb. 28, 1984
John E Deutschman, Kingston, CA;
Alcan International Limited, Montreal, CA;
Abstract
A process for treating fluoride-contaminated scrap lining material from electrolytic reduction cells comprises mixing the material with 7-30 parts of sulphuric acid and sufficient water to bring liquid content to 60-80 parts per 100 parts of lining material, mixing in sufficient lime to at least neutralize the sulphuric acid and make the slurry slightly alkaline, the slurry then being allowed to set into a solid mass. The slurry should be of a paste-like consistency. The lime may be wholly calcium hydroxide, but a substantial proportion may be in the form of calcium carbonate. The scrap, before or after the above treatment with lime and sulphuric acid, is preferably heated to 150.degree.-500.degree. C. in the presence of water vapor to destroy cyanides.