Teledyne Industries, Inc.

Kenneth C Ash

John C Haygarth

John R Peterson

William A Crocker

David R Lee

Lawrence J Jacoby

Dorothy P Carter

Ralph H Nielsen

Jon A Riesen

Richard A Rosenau

Robert S Yih

Donald Morris

A process for the recovery of substantially pure zirconium values from zircon sand which also contains Ra, U, Hf, Pb and other metal values, comprising contacting zircon sand in a chlorinator with a chlorination medium to form an off-gas stream containing chlorides of Zr, Hf, Si, and tract U. The off-gas stream is passed to a condenser to remove volatile Si chlorides and thereby provide a product stream containing condensed chlorides of Zr, Hf and tract U, treating the product stream in acidic aqueous medium in a separation stage to separate the principal Hf values from the principal Zr values. Adjusting the pH of the resulting effluent to between about 3 to about 7 in a second stage to precipitate the trace U values. The residue stream is treated by

Zirconium-hafnium separation and purification process

A method of essentially preventing the formation of 3-mercapto-4-methyl-2-pentanone by selectively controlling an ammonium thiocyanate-methyl isobutyl ketone regeneration system by maintaining the pH in the range of 4 to 9, and the temperature below 150.degree. F.

Removal of 3-mercapto-4-methyl-2-pentanone from zirconium/hafnium

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Corvallis, OR, United States of America

Kenneth C Ash