NIOSHTIC-2 Publications Search

Process for the Preparation of Calcium Superoxide.

Ballou EV; Wood PC; Wydeven TJ; Spitze LR

U S Pat 4 101 644 1978 Jul; :

10012041

Calcium superoxide is prepared in high yields by spreading a quantity of calcium peroxide piperoxyhydrate on the surface of a container over an area of 18 to 300 cm2/g of diperoxyhydrate; positioning said container in a vacuum chamber on a support structure through which a coolant fluid can be circulated; partially evacuating the chamber, allowing the temperature of the diperoxyhydrate to reach approximately 0 deg to approximately 40 deg c with the use of external heating or cooling fluid as needed, maintaining the temperature for a sufficient time to complete the disproportionation of the diperoxyhydrate to calcium superoxide, calcium hydroxide, oxygen, and water; while maintaining a partial vacuum, constantly and systematically removing the water as it is formed by sweeping the chamber with a current of dry inert gas and/or by condensing the water on a cold surface; and finally recovering the calcium superoxide produced. Calcium peroxide diperoxyhydrate is prepared by adding to cao2.8H2o sufficient concentrated h2o2 to effect the chemical transformation. Maintain the temperature at -15.5 Deg to -15.0 Deg c for 0.75 to 2 h. Filter, wash with dry isopropanol at -15 deg to -18.5 Deg c. Filter again and dry in a stream of co2-free air at relative humidity of 0- 0.5 pct. Store at -10 deg c, or preferably at -195 deg c (liquid n2). Note: it is not clear why this patent is listed as a Bureau patent, as the inventors are not Bureau of Mines personnel, and the patent appears to have been assigned to the National Aeronautics and Space Administration.

19780701

PA;

1978

PAT 4,101,644

WO;

U.S. Pat. 4,101,644, July 18, 1978; Chem. Abstr. Not Found