Title:  Zirconium Oxide 
CAS Registry Number:  1314-23-4 
Additional Names:  Zirconia;  zirconium dioxide;  zirconic anhydride 
Molecular Formula:  O2Zr 
Molecular Weight:  123.22 
Percent Composition:  O 25.97%, Zr 74.03% 
Line Formula:  ZrO2 
Literature References:  Occurs in nature as the mineral baddeleyite.  Prepn:  Clark, Reynolds, Ind. Eng. Chem. 29, 711 (1937); Henderson, Higbie, J. Am. Chem. Soc. 76, 5878 (1954). 
Properties:  White, heavy, amorphous, odorless, tasteless powder or monoclinic crystals.  Also forms tetragonal crystals above ~1100°; cubic above ~1900°.  d 5.85.  mp 2680°.  bp 4300°.  Practically insol in water; slightly sol in HCl, HNO3; slowly sol in HF; dissolves on heating with a mixt of 2 parts H2SO4 and 1 part H2O.  Fusion with sodium carbonate results in the formation of sodium zirconate which dec hydrolytically with water to form sodium hydroxide and practically insol zirconium hydroxide. 
Melting point:  mp 2680° 
Boiling point:  bp 4300° 
Density:  d 5.85 
Use:  Instead of lime for the oxyhydrogen light; with earths of the yttrium group in incandescent lighting (Nernst lamps); as pigment, abrasive; manuf enamels, white glass, refractory crucibles, and furnace linings. 
Therap-Cat:  Dermatologic.   |