PROCESS FOR PREPARING N-PHOSPHONOMETHYL-GLYCINE

摘要

PROCESS FOR PREPARING N-PHOSPHONOMETHYL-GLYCINE The invention relates to an improvement of a process for preparing N-phosphonomethyl-glycine by oxydation of N-phosphonomethyl-imino-diacetic acid in an aqueous sulphuric acidic medium with hydrogen peroxide. A characteristic feature is using a waste acid liquor as reaction medium formed as aqueous sulphuric acid and obtained after the separation of N-phosphono-methyl-glycine when carrying out oxydation. This solution is optionally diluted with water until a concentration of 12-18 weight% of sulphuric acid and 3-5 weight% of N-phosphonomethyl-glycine.