Hoechst Aktiengesellschaft

Theo Dahmen

Werner Kowalski

Hans Haas

Markus Erpenbach

Gunther R Schimmel

Robert Queck

Gerhard Hartlapp

Helmut Klee

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.

Spheroidal alkali metal polyphosphates of low apparent density, and

A granular hydrated product consisting completely or partially of sodium triphosphate for use in detergent and cleaning compositions is made. To this end, pulverulent sodium triphosphate containing less than 22 wgt % water is compacted by initially mixing it with a quantity of water sufficient for hydrating at most 100% of the sodium triphosphate to the hexahydrate and then continuously admitting the resulting mixture to a zone inside which it is made into solid matter under pressure.

Process for making a granular product containing sodium triphosphate

Hexagonal phosphorus pentoxide of diminished reactivity is made by burning liquid yellow phosphorus with a mixture of dry air and pure oxygen inside a combustion zone with the resulting formation of a gas stream containing phosphorus pentoxide; next, the gas stream coming from the combustion zone is passed initially through an intermediary zone indirectly cooled by means of fluidized matter and then through a condensing zone fitted with an immersion tube indirectly cooled by means of fluidized matter; the gas stream is passed through the immersion tube at a mean temperature of 450.degree. to 600.degree. C. and allowed to remain in the immersion tube over a period of 2 to 5 seconds.

Process for making phosphorus pentoxide of diminished reactivity

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 peoduced inside the spray tower. Apparatus for carrying out the process.

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.

Hexagonal phosphorus pentoxide is made in an apparatus comprising a combustion chamber (1) which has a plurality of cooling pipes (10) disposed at its inside wall and is connected through a gas cooler (3) to a condensation chamber (4), the gas cooler (3) comprising a system of cooling pipes (5) which terminate, similarly to an open immersion tube, above the bottom portion of the condensation chamber (4), whose walls are provided with a cooling device (6).

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Bruhl, Germany

Theo Dahmen