Production of granular alkali metal diphosphates or triphosphates
AssigneeHoechst Aktiengesellschaft
InventorsAlexander Maurer, Renate Adrian, Herbert Panter, Gero Heymer, Dieter Nolker
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Abstract
The invention relates to a process for making granulated, partially or completely hydrated alkali metal diphosphates or triphosphates. To this end, the invention provides for alkali metal diphosphates or triphosphates which consist to an extent of at least 20% of particles with a size of less than 0.045 mm and are hydrated to an extent of less than 90%, based on the phosphates' theoretical content of water of hydration, to be intensively mixed and granulated in the presence of water and an ammonium polyphosphate, this latter being used in a proportion of about 0.5 to 50 weight %, based on the quantity of water used.
Claims9
In the process for making granular, partially or completely hydrated alkali metal diphosphates or triphosphates, wherein pulverulent, anhydrous or partially hydrated alkali metal diphosphates or triphosphates are intensively mixed and granulated in the presence of water and a phosphate salt other than the alkali metal diphosphate or triphosphate, the improvement which comprises:
- intensively mixing and granulating alkali metal diphosphates or triphosphates consisting to an extent of at least 20% of particles with a size of less than 0.045 mm and hydrated to an extent of less than 90%, based on the phosphates' theoretical content of water of hydration, in the presence of a quantity of water at most necessary for completely hydrating the alkali metal diphosphates or triphosphates and in the presence of an ammonium polyphosphate, this latter presenting a degree of condensation of 3 up to about 1000 and being used in proportion of about 0.5 to 50 weight %, based on the quantity of water used.
Dependencies are inferred from the claim text.