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US 5,075,088 AGranted
Production of red phosphorus
AssigneeAlbright & Wilson Limited
InventorsEdward J. Lowe, William S. Holmes
Life of this patent
Estimating the term…
Abstract
Amorphous red phosphorus useful for matches, or as flame retardant is made by forming a slurry of 10-45% red phosphorus in molten white phosphorus, reducing the content of yellow phosphorus to less than 20% of the red phosphorus by separation at less than 280.degree. C., and then heating the product at above 295.degree. C. to convert, and preferably also evaporate, the white phosphorus.
Claims24
A process for the production of friable red amorphous phosphorus
- from a slurry of red phosphorus in molten white phosphorus, which slurry comprises 10 to 45% by weight of red phosphorus, which process comprises
- (i) separating white phosphorus from the slurry of red phosphorus, whilst maintaining the slurry at a temperature of less than 280.degree. C. until the amount of white phosphorus present in the red phosphorus product obtained is less than 20% of the total weight of the red phosphorus, and
- (ii) heating the red phosphorus product to a temperature above 295.degree. C. under conditions to convert at least some white phosphorus to red phosphorus to leave a friable red amorphous phosphorus product.
Dependencies are inferred from the claim text.