FIELD: chemical technology.
SUBSTANCE: invention relates to a method for purifying melamine melt prepared by pyrolysis of urea under high pressure. In the first step melamine melt is contacted in countercurrent with hot gaseous NH3 with temperature 324-450°C and with NH3 from the second step. In the second step melamine melt is contacted with cold NH3 with temperature 150-300°C, and melt is cooled to temperature by 1-30°C higher the melamine melting point and depending on pressure. If necessary, melt after the second step is remained for from 10 min to 10 h followed by treatment by the any known method. Invention provides preparing melamine of purity 99.6 weight% in a cleaning column at separate addition of NH3.
EFFECT: improved purifying method.
8 cl, 1 dwg, 1 ex
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