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:
Feb. 14, 1995
Filed:
Mar. 28, 1994
Applicant:
Inventor:
Robert G Guess, Beverly, MA (US);
Assignee:
Romar Technologies, Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C02F / ;
U.S. Cl.
CPC ...
210719 ; 210717 ; 210720 ; 210724 ; 210726 ; 210912 ; 210913 ; 210914 ; 75712 ; 75714 ; 75739 ;
Abstract
Heavy metal ions react with ferrous dithionite in acidic aqueous solution. They are reduced to metallic particles that are suitable for recycling and reuse when recovered from the acidic water. Chelating agents that are present are deactivated by bonding to the ferrous ions. Ferrous dithionite, (FeS.sub.2 O.sub.4) is either generated in-situ or ferrous ions and dithionite ions can be provided by other methods. An alkali metal hydroxide is utilized to precipitate remaining heavy metal ions including ferrous and ferric ions.