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:
Aug. 19, 1986
Filed:
Jun. 25, 1985
Applicant:
Inventors:
Michael A Rice, Bethlehem, PA (US);
Stewart T Herman, Hellertown, PA (US);
Assignee:
Bethlehem Steel Corporation, Bethlehem, PA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C02F / ; C02F / ;
U.S. Cl.
CPC ...
210713 ; 210721 ; 210724 ; 210726 ; 210904 ; 210912 ; 423101 ; 423367 ;
Abstract
A method of removing complexed zinc-cyanide from wastewater involving a multiple stage process including, in a first step, control of ferrous ions to a critical minimum concentration of 250 to 400 ppm, together with pH control in the first and also a second step, together with recycling of a portion of sludge precipitated in the process. Improved sludge stability is achieved by aeration to oxidize precipitated ferrous hydroxide to ferric hydroxide, immediately before settling the sludge in a thickener.