Patent · US Expired

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

US4717557A · kind A · utility

8Cited by

5References

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	Apr 3, 1986
Grant date	Jan 5, 1988
Priority date	—
Expiry date	Apr 3, 2006

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB01D1/18
WIPO fieldChemical engineering
WIPO sectorChemistry

Abstract

Alkali metal polyphosphates consisting substantially of hollow spheroidal particles with an apparent density of less than 320 g/l are made. To this end, an aqueous alkali metal orthophosphate solution and an aqueous solution of an inflating agent are simultaneously forced under a pressure of 6-40 bars into a fluidization zone; the two solutions are fluidized in the fluidization zone by injecting a finely dispersed permanent gas maintained under a pressure higher than the two solutions and the fluidized solutions are 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.