Skip to Content
Find More Like This
Return to Search

Method for separating metal chelates from other materials based on solubilities in supercritical fluids

United States Patent

February 13, 2001
View the Complete Patent at the US Patent & Trademark Office
A method for separating a desired metal or metalloi from impurities using a supercritical extraction process based on solubility differences between the components, as well as the ability to vary the solvent power of the supercritical fluid, is described. The use of adduct-forming agents, such as phosphorous-containing ligands, to separate metal or metalloid chelates in such processes is further disclosed. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones; phosphine oxides, such as trialkylphosphine oxides, triarylphosphine oxides and alkylarylphosphine oxides; phosphinic acids; carboxylic acids; phosphates, such as trialkylphosphates, triarylphosphates and alkylarylphosphates; crown ethers; dithiocarbamates; phosphine sulfides; phosphorothioic acids; thiophosphinic acids; halogenated analogs of these chelating agents; and mixtures of these chelating agents. In especially preferred embodiments, at least one of the chelating agents is fluorinated.
Wai; Chien M. (Moscow, ID), Smart; Neil G. (Workington, GB), Phelps; Cindy (Moscow, ID)
Idaho Research Foundation, Inc. (Moscow, ID)
09/ 306,948
May 7, 1999
ACKNOWLEDGEMENT OF GOVERNMENT SUPPORT This invention was funded in part by the United States Department of Energy under Grant No. DE-FG02-91ER75679. The United States Government may have certain rights in this invention as a result of this grant.