Method for producing pure melamine
AssigneeAgrolinz Melamin GmbH
InventorGerhard Coufal
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Abstract
The invention relates to a method for producing pure melamine. According to this method, the melamine melt, which is produced from urea in a high-pressure process, is cooled and ammonia is added until it reaches a temperature of approximately 1 to 50° C. above the melting temperature of the melamine as dependent on the respective pressure of ammonia and then either a) quenched with water or an aqueous solution or suspension containing ammonia and/or melamine so that the melamine solidifies or b) quenched with cold liquid or gaseous ammonia, so that the melamine solidifies, the melamine then being cooled further with water or an aqueous solution or suspension containing ammonia and/or melamine and c) the melamine is then isolated.
Claims12
A method for producing pure melamine wherein the melamine melt prepared from urea in a high-pressure process, optionally after stripping of the off-gases and optionally after dwelling in an ageing container, is cooled to a temperature which is about 1 to 50° C. above the melting point of melamine dependent on the respective ammonia pressure, with the addition of ammonia, after which quenching is effected with water or an aqueous ammonia- and/or melamine-containing solution or suspension and the melamine is solidified and isolated.
Dependencies are inferred from the claim text.