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US 6,603,001 B1Granted
Process for preparing solid melamine
AssigneeAgrolinz Melamin GmbH
InventorGerhard Coufal
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Abstract
The invention relates to a method for producing solid melamine by expanding liquid, ammoniacal melamine which is mixed with excess ammonia, whereby a dispersion is produced. Said dispersion is expanded, optionally after it has been held under ammonia pressure, whereby solid melamine is deposited. The solid melamine is optionally held under ammonia pressure. Expansion is then optionally carried out in any particular order, along with cooling to room temperature and the pure melamine is isolated.
Claims19
A process for preparing solid melamine by depressurizing liquid ammonia-containing melamine, wherein:
- a) the liquid ammonia-containing melamine is mixed with excess ammonia, whereupon a dispersion of gaseous ammonia and liquid melamine forms,
- b) optionally, the dispersion is aged under the pressure generated by ammonia,
- c) the dispersion is depressurized, whereupon solid melamine precipitates,
- d) optionally, the solid melamine is aged under the pressure generated by ammonia,
- e) and then, optionally and in any desired sequence, there is further depressurization to atmospheric pressure, and cooling to room temperature, and the melamine is isolated.
2 more elements
Dependencies are inferred from the claim text.