Procedure for the production of highly Pure melamine

摘要

Method for preparing melamine High PU reads from a reaction of urea under pressureCharacterized in that after the transformation reaction is carried out further treatment of melamine which consists in the following steps: a) separates the gas mixture of NH3 / CO2 melamine Liquid(b) eventually reduces the dissolved CO2 in the melamine liqui is bubbled with gaseous Ammonia (c) allow the liquid melamine during an average time of 0 to 8 hoursAt a temperature between 430 degrees Celsius and the pun to fusion of melamine and a pair of ammonia partial pressure of 50 to 400 bars, and (d) is cooled slowly and controlled,Decreasing the temperature (a),(b) or (c) to a temperature of between 330 and 270 degrees with a Speed of up to 150 degrees Celsius cooling / min and a partial pressure of ammonia from 50 to 400 BAres, whereas the higher pressures can obtain Cooling speeds increased and vice versa, Lower pressures provided speeds enfriamien - DED to minors, and thenIn any order, eliminates the pressure - temperature Cools ambien and obtained high purity melamine is the rule of dust.