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. 09, 1993
Filed:
Jul. 08, 1991
Charles R Hughes, Hellertown, PA (US);
Stewart T Herman, Hellertown, PA (US);
Richard N Steinbicker, Allentown, PA (US);
Bethlehem Steel Corporation, Bethlehem, PA (US);
Abstract
The present invention relates to a method of completely recovering nickel and zinc metal from multiple plating process waste streams by first separating the waste streams into a clean, relatively constant flow and/or concentration fraction and a dirty, variable flow and/or concentration fraction. Metal is recovered from the clean fraction by ion-exchange so as to concentrate the extracted metals for direct return to the plating bath. The effluent from the ion-exchange step is then blended with the dirty, variable flow and concentration fraction. This blended flow is first neutralized and then precipitated in a two-stage process using a sodium hydroxide solution. The resultant slurry containing the metal precipitate is filtered to yield a filter cake containing recovered nickel and zinc. This filter cake can then be further processed to recover the metal for reintroduction into the plating bath or for other uses.