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. 09, 2008
Filed:
Jul. 22, 2004
Koji Ando, Niihama, JP;
Keiji Kudo, Niihama, JP;
Koji Ando, Niihama, JP;
Keiji Kudo, Niihama, JP;
Sumitomo Metal Mining Co., Ltd., Tokyo, JP;
Abstract
A method for concentrating precious metals contained in the leaching residue discharged from a copper hydrometallurgical process by removing pyrite from the residue. A method for concentrating precious metals in the leaching residue containing pyrite, elementary sulfur, precious metals and gangue, discharged from a copper hydrometallurgical process which comprises steps of leaching in an acidic, aqueous solution, reducing the copper-containing leaching liquor and electrolysis for copper recovery to treat copper sulfide ores, comprising (1) pyrolysis step in which the leaching residue is thermally treated at 550.degree. C. or higher in a non-oxidative atmosphere, to produce the calcined ore containing pyrrhotite, precious metals and gangue, and (2) a re-leaching step in which the calcined ore is re-leached in an acidic, aqueous solution, to be separated into the re-leaching residue and iron-leached liquor, the former containing elementary sulfur, precious metals and gangue.