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:
Jul. 14, 1998
Filed:
May. 12, 1995
Bror Goran Nyman, Ulvila, FI;
Stig-Erik Hultholm, Pori, FI;
Outokumpu Harjavalta Metals Oy, Harjavalta, FI;
Abstract
A method for preventing the formation of jarosite, ammonium and alkali metal double salts during solvent extraction and leaching of an acidic leaching process in which an aqueous solution containing at least two metals are separated selectively from each other, and ammonium and alkali salts in the solution are neutralized prior to separation of the metals from the solution, and the formation of harmful double salts are prevented by using an exchange ion, which includes separating a first metal of the at least two metals by solvent extraction after neutralizing the solvent extraction solution by means of ammonium or alkali base; contacting the extraction solution with an aqueous solution containing an exchange ion, and replacing the ammonium or alkali ions contained in the extraction solution with the metal exchange ion during a pre-extraction step, whereby the ammonium or alkali ions are transferred into the aqueous solution to prevent formation of ammonium and alkali based double salts in a leach process solution.