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. 01, 1994
Filed:
Dec. 31, 1992
Joao J de Oliveira Bandarra, Loures, PT;
Alexandre J Ganchas de Carvalho, Lisbon, PT;
William Heggie, Palmela, PT;
Plurichemie Anstalt, Liechtenstein, DE;
Abstract
The present invention concerns a process for the recovery of a noble metal from an inorganic and/or organic residue in the form of a tellurium/noble metal precipitate characterised by adding a solvent having a boiling point above 120.degree. C. to the residue, removing by distillation water and other residual solvents having boiling points below the boiling point of the added solvent, adding the tellurium or reducible tellurium compound, and then refluxing at atmospheric pressure before separating the tellurium/noble metal precipitate. The process of the present invention also allows the simultaneous recovery of the tertiary phosphine as its oxide from a residue containing a tertiary phosphine by the further stages of concentrating the mother-liquors remaining after separation of the tellurium/noble metal precipitate, recovering the added high boiling point solvent and isolating the tertiary phosphine in the form of its oxide by precipitation with water.