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:
Sep. 17, 1991
Filed:
Jul. 06, 1990
Applicant:
Inventor:
Thomas A Davis, Annandale, NJ (US);
Assignee:
The Graver Company, Union, NJ (US);
Primary Examiner:
Int. Cl.
CPC ...
B44C / ; C23F / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
156642 ; 156665 ; 156345 ;
Abstract
A method for the recovery and recycling of sodium hydroxide from the waste solution of aluminum etching operations. The method utilizes a dialysis membrane column or stack to initially remove sodium hydroxide from the waste solution and return it to the etch tank base solution sufficiently concentrated to carry on the basic etching operation. The method permits the recovery of salable quantities of aluminum hydroxide.