PROCESS FOR THE PREPARATION OF A POWDER COMPRISING ONE OR MORE DERIVATIVES OF GLYCINE-N,N-DIACETIC ACID AND/OR ONE OR MORE DERIVATIVES OF GLUTAMINE-N,N-DIACETIC ACID AND METHYLGLYCINE-N,N-DIACETIC ACID TRISODIUM SALT POWDER

摘要

A process is proposed for the preparation of a powder comprising one or morederivatives of glycine-N,N-diacetic acid and/or one or more derivatives ofglutamine-N,N-diacetic acid with a degree of crystallinity of a 30%, startingfrom an aqueous solutioncomprising the one or more derivatives of glycine-N,N-diacetic acid and/or theone ormore derivatives of glutamine-N,N-diacetic acid in a concentration range from20 to 60%by weight, based on the total weight of the aqueous solution, where theaqueous solutionis concentrated in a first process step in an evaporator with rotatinginternals, which arearranged at a distance relative to the inside wall of the evaporator of 5 1%of the diameterof the evaporator, to give a crystal slurry with a solids concentration in therange from 60to 85% by weight, based on the total weight of the crystal slurry, and wherein a secondprocess step the crystal slurry is left to ripen in a paste bunker and then ina thin-filmcontact dryer, and where the residence time in the paste bunker and in thethin-filmcontact dryer is in total a 15 minutes.