| 摘要 |
PCT No. PCT/FI94/00307 Sec. 371 Date Jun. 13, 1996 Sec. 102(e) Date Jun. 13, 1996 PCT Filed Jul. 1, 1994 PCT Pub. No. WO95/01345 PCT Pub. Date Jan. 12, 1995The invention relates to a process for the preparation of melamine from urea by feeding molten urea and hot ammonia gas into a reactor having a pressure within the range 50-150 bar and a temperature within the range 360 DEG -430 DEG C., whereby a reaction product is obtained which contains a liquid melamine melt and a gas mixture. This gas mixture is separated from the liquid melamine melt, and the liquid melamine melt thus obtained is directed to a vaporizer and is vaporized therein, and the melamine-containing gas obtained from the vaporizer is cooled in a quencher, in which case the melamine crystallizes in a very pure state, the purity being typically at minimum 99.9%.
|
