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:
Dec. 24, 2019
Filed:
Nov. 29, 2016
Xiamen Institute of Rare Earth Materials, Xiamen, Fujian, CN;
XIAMEN INSTITUTE OF RARE EARTH MATERIALS, Xiamen, Fujian, CN;
Abstract
A method for recovering thorium and rare earth elements from rare earth waste residues includes the steps of (1) mixing rare earth waste residues with an inorganic acid and heating to obtain a stock solution containing thorium and rare earth elements; (2) extracting thorium and rare earth elements from the stock solution with an organic phase containing an extractant; (3) washing the organic phase obtained after extraction in step (2) with a washing solution to move rare earth elements into the aqueous phase and leave thorium in the organic phase; (4) back-extracting the organic phase containing thorium obtained in step (3) with a back-extraction solution to extract move thorium in the organic phase into the aqueous phase. The extractant contains alkyl phosphonic acid monoalkyl ester and dialkylphosphinic acid.