Patent documents


https://patents.google.com/patent/US8968688B2/en

Recovery of rare earth elements and compounds from coal ash

Abstract

Rare earth elements are recovered from coal ash. The coal ash with rare earth elements can be treated with a mineral acid to form an aqueous mineral acid solution. The aqueous mineral acid solution can be extracted to form an organic solution that includes the rare earth salts. The organic solution can be mixed with water to form an aqueous solution that includes the rare earth salts. The rare earth elements are separated from the aqueous solution.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. provisional patent application no. 61/625,292, filed Apr. 17, 2012, the entire contents of which are incorporated by reference herein and owned by the assignee of the instant application.