Patent · US Expired

Process for the preparation of substantially crystalline calcium sodium metaphosphate

US4725368A · kind A · utility

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12Claims
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Assignee

Inventors

Key dates

Filing dateNov 5, 1986
Grant dateFeb 16, 1988
Priority date
Expiry dateNov 5, 2006

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC01B25/45
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Substantially crystalline calcium sodium metaphosphate having a degree of crystallinity from about 60% to about 75% as determined from density and differential thermal analysis measurements is prepared by (a) forming a dry mixture of source materials for CaO, Na.sub.2 O, and P.sub.2 O.sub.5 in proportions sufficient to provide a CaO/Na.sub.2 O/P.sub.2 O.sub.5 mol percent ratio on a dry basis of about 29.0-34.0/16.0-18.0/50.0-53.0 and (b) heating the mixture at a temperature and for a time sufficient devolatilize the mixture and calcine the resulting mixture to form the substantially crystalline calcium soldium metaphosphate.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.