Process for the continuous preparation of phosphorus(III) oxide

摘要

The invention relates to the preparation of phosphorus(III) oxide from vaporous white phosphorus and an oxygen/inert gas mixture. The aim and object of the invention is the development of a continuous process employing atmospheric pressure for the preparation of P4O6 with high yields which permits a specific separation and continuous discharge from the synthesis apparatus of the reaction product mixture composed of phosphorus oxides. According to the invention, vaporous phosphorus is reacted with an oxygen/inert gas mixture in the molar ratio P4:02:inert gas of 1:2.6: > 0 to 1:3.3:15 at temperatures of 2000-6000 K and the vaporous reaction product mixture is cooled in three cooling stages following directly one after the other having different cooling rates, with the addition of inert gas and liquid reaction product mixture. The flowable reaction product mixture obtained after condensation is withdrawn and is isolated in a second process step or is directly processed further to give secondary products.