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. 06, 2011
Filed:
Feb. 28, 2008
George Puvvada, Markham, CA;
George Puvvada, Markham, CA;
Other;
Abstract
The invention is a method of separating metals such as zinc, lead and cadmium from iron in secondary feed stocks such as EAF Dust, BOF Sludge, mill scale, iron fines, tire dust and other iron and zinc containing residues and dusts. The method includes the steps of reduction roasting the feed stocks at a volatizing temperature sufficient to volatilize the zinc and other metals into metal fumes but insufficient to volatize iron and then collecting the metal fumes as a metal dust. The metal dust is then leached with a leaching liquid to form a leach liquor and a leach residue. The leach liquor is then purified by zinc dust cementation to form a purified liquor and a zinc dust cement residue. The purified liquor is then separated from the zinc dust cement residue, and a zinc recovery step is then performed on the purified liquor.