Zirconium-hafnium separation and purification process

US5160482A · kind A · utility

Assignee

• Teledyne Industries, Inc. · US

Inventors

• Kenneth C. Ash · Corvallis, US
• William A. Crocker · Corvallis, US
• John C. Haygarth · Corvallis, US
• David R. Lee · Lebanon, US
• Donald E. Morris · New Orleans, US
• John R. Peterson · Ashburn, US
• Jon A. Riesen · Albany, US
• Robert S. Yih · Salem, US

Key dates

• Filing date: Mar 2, 1989
• Grant date: Nov 3, 1992
• Expiry date: Mar 2, 2009

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P10/20
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

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 PA1 (A) leaching with an acidic aqueous system to solubilize the trace Ra, Pb and other metal values while settling out the unreacted zircon sand and chlorination medium, and contacting the resultant leach liquor first with Ba++ ions and then with SO.sub.4 =ions to co-precipitate the barium and trace radium ions as a sulfate complex and the trace lead and other metal ions as their sulfates, or by PA0 (B) contacting at least a portion o…