Patent · US Expired

Spheroidal alkali metal polyphosphates of low apparent density, and apparatus for making them

US4968490A · kind A · utility

1Cited by

6References

3Claims

0Family size

Assignee

Hoechst GmbH · DE

Inventors

Werner Kowalski · Weilerswist, DE
Hans Haas
Theo Dahmen · Münstermaifeld, DE
Markus Erpenbach · Cologne, DE

Key dates

Filing date	Jul 16, 1987
Grant date	Nov 6, 1990
Priority date	—
Expiry date	Jul 16, 2007

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01B25/412
WIPO fieldChemical engineering
WIPO sectorChemistry

Abstract

Alkali metal polyphosphates consisting substantially of hollow spheroidal particles with an apparent density of less than 350 g/l are made. To this end, an alkali metal orthophosphate solution is forced under a pressure of 6-40 bars into a fluidization zone; the orthophosphate solution is fluidized in the fluidization zone by injecting a finely dispersed permanent gas maintained under a pressure higher than the orthophosphate solution; and the fluidized orthophosphate solution is sprayed with the aid of a plurality of single medium nozzles arranged downstream of the fluidization zone through a flame zone produced inside the spray tower. Apparatus for carrying out the process.

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