摘要 |
Asbestiform crystalline calcium sodium metaphosphate fibers are prepared by (a) forming a homogeneous melt of substantially crystalline calcium sodium metaphosphate having a composition on a dry basis equivalent to a CaO/Na2O/P2O5 mol percent ratio of about 29.0-34.0/16.0-18.0/50.0-53.0 and a degree of crystallinity from about 60% to about 75% as determined from density and differential thermal analysis measurements, (b) supercooling the homogeneous melt, (c) seeding the supercool melt with calcium sodium metaphosphate crystals, (d) maintaining the seeded supercooled melt at the seeding temperature under isothermal conditions for a time sufficient to form crystalline blocks of calcium sodium metaphosphate, and (e) fiberizing the crystalline blocks. |