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. 23, 2010
Filed:
May. 03, 2006
George Puvvada, Markham, Ontario, CA;
Douglas Bartholomew, Naples, FL (US);
George Puvvada, Markham, Ontario, CA;
Douglas Bartholomew, Naples, FL (US);
Other;
Abstract
The present invention is a method of recovering valuable metals from a quantity of furnace dust consisting the following steps. A first leaching step wherein the furnace dust is leached at atmospheric pressure in a first leaching solution to produce a first leach liquor and a first leach residue, the first leaching solution consisting of an aqueous mineral acid solution. The first leach liquor is then separated from the first leach residue. A second leaching step is then performed wherein the first leach residue is atmospherically leached in a second leaching solution to form a second leach liquor and a second leach residue, the second leaching solution comprising a solution of aqueous HCl with a reductant. The second leach liquor is then separated from the second leach residue. A zinc precipitation step is then performed wherein zinc is precipitated from the second leach liquor by treating the second leach liquor with a quantity of alkali, the quantity of alkali selected to adjust the pH of the second leach liquor sufficiently to precipitate out the zinc in the form of a zinc salt in a third residue leaving a third liquor and then separating the third residue containing zinc from the third liquor.