UREA CONTAINING FORMALDEHYDE IN THE METHOD OF PRODUCING MELAMINE BY UREA PYROLYSIS AND A RELATIVE METHOD FOR PRODUCING MELAMINE

摘要

1. The use of urea containing formaldehyde in the method for producing melamine by pyrolysis of urea. 2. The use according to claim 1, characterized in that formaldehyde is present in urea in an amount of 10 to 5000 parts by weight. per million, preferably from 50 to 2000 parts by weight per million, even more preferably from 100 to 500 parts by weight per million. 3. The use according to claim 1 or 2, characterized in that formaldehyde is present in urea as a result of the urea production process itself. The use according to claim 1, characterized in that formaldehyde is added to the urea coming from the urea plants before the said urea is fed to the melamine plant. The use according to claim 1, characterized in that the urea is any type of urea, for example, a variety for fertilizers or technical grade or a mixture of urea of various types. The use according to claim 1, characterized in that the formaldehyde is added as such or in the form of a compound or mixture containing formaldehyde, for example, urea. A method for producing melamine by pyrolysis of urea, characterized in that it is carried out using urea containing formaldehyde as a starting material. The method according to claim 7, characterized in that it is a method carried out at high pressure, or a method carried out at low pressure, preferably a method carried out at high pressure. The method according to claim 7 or 8, characterized in that the formaldehyde is present in urea in an amount of 10 to 5000 parts by weight. per million, preferably from 50 to 2000 parts by weight per million, even more preferably from 100 to 500 parts by weight per million. 10. The method according to claim 7, characterized