IMPROVED PROCESS FOR THE PRODUCTION OF MELAMINE WITH AN INCREASED YIELD

摘要

A process is described for recovering from the crystallization mother liquor of melamine both the residual saturation melamine and oxyaminotriazines (OAT), comprising an ultrafiltration of the flushing mother liquor for separating the OAT in the colloidal state from the mother liquor containing them, said ultrafiltration producing a permeate and a retentate in aqueous solution, the permeate impoverished in OAT being recycled to the preparation step of the aqueous solution of raw melamine, said process being characterized in that the retentate is recycled to the synthesis reactor.