Abstract: Processes for the production of tantalum alloys are disclosed. The processes use aluminothermic reactions to reduce tantalum pentoxide to tantalum metal.
Abstract: A process of recovering platinum group metals (PGMs) from a pregnant solution or leachate containing PGM values and base metals, typically a cyanide solution or leachate. A non-selective precipitation of the PGM values and base metals to form an insoluble precipitate comprising the PGM values and base metals is followed by selective leaching of the precipitate. The selective leaching forms a leach solution containing the base metals and a residue containing the PGM values, or a leach solution containing the base metals and PGM values and a depleted residue. The base metals are recovered from the leach solution and the PGM values are recovered from the residue or the leach solution, depending on the selective leaching. The non-selective precipitation of the PGM values and base metals is carried out by controlled reduction of the pH of the pregnant solution or leachate to a pH of about 2.
Type:
Grant
Filed:
April 8, 2004
Date of Patent:
June 9, 2009
Assignee:
Lonmin PLC
Inventors:
Alan Bax, Grenvil Marquis Dunn, John Derek Lewins