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:
May. 07, 2002
Filed:
May. 30, 2000
Jan-Eric Sundkvist, Skellefteå, SE;
Boliden Mineral AB, , SE;
Abstract
A method for winning the valuable metal content of a leaching solution acidified with sulphuric acid, by solvent extraction and electrowinning and a following final product winning stage, for instance an electrowinning stage, wherein the pH of the leaching solution is raised successively to precipitate out the iron and arsenic present in a first precipitation stage, removing said first precipitate, and precipitating the valuable metal content of the leaching solution substantially totally in a following precipitation stage. The resultant precipitate containing valuable metal and gypsum is removed and leached in an acid environment to re-dissolve the valuable metal content, and the thus formed acid solution and its metal content are delivered to a solvent extraction circuit in which the metal content is converted to a substantial degree to an acid electrolyte from which metal or some other end product is won. The acid solution deplete of valuable metal and deriving from the solvent extraction stage can be returned to the stage in which the valuable metal content is re-dissolved and, when electrowinning is used for winning the end product, electrolyte deplete of valuable metal can be cycled from the electrowinning stage to the solvent extraction circuit.