William R Riggs

US Patent:

44252307, Jan 10, 1984

Filed:

Feb 16, 1982

Appl. No.:

6/348923

Inventors:

Carlos Andress - Boulder CO
William F. Riggs - Humble TX

Assignee:

Oreprep Chemicals, Inc. - Houston TX

International Classification:

B03D 114

US Classification:

209167

Abstract:

Dithiocarbonic acid, trithiocarbonic acid, water soluble salts of dithiocarbonic acid or trithiocarbonic acid or mixtures thereof when contacted with a mixed sulfide ore effectively depresses copper and iron sulfides thereby permitting molybdenite to be recovered by froth flotation. In copper concentrates produced by a flotation process, the organic collector reagents adhering to the surface of the copper and iron sulfides may be, and preferably are, stripped by conventional physical or chemical means prior to contacting the copper concentrate with the trithiocarbonate depressants of the invention. However, the trithiocarbonates of the invention have been found to be effective depressants of copper and iron sulfides in concentrates which are not stripped prior to treatment with the depressant.