METHOD OF PREPARING MELAMINE OF HIGH PURITY, METHOD OF EXTRACTION AND PURIFICATION OF MELAMINE

摘要

FIELD: chemical technology. SUBSTANCE: melamine is prepared by urea conversion and melamine purification is carried out for two different crystallization stages. The first stage of crystallization involves preparing crude melamine crystals that were washed with mother liquid feeding after the second stage of crystallization. This mother liquid is purified preliminary by special treatment. The second crystallization stage involves dissolving crude crystals with recycling mother liquid feeding from the terminal centrifugation, filtration of the obtained solution, recrystallization, separation by centrifugation and crystals washing with demineralized water. EFFECT: improved method of melamine preparing.