| 摘要 |
The present invention concerns a process for the preparation of free flowing granules of low hygroscopicity of one or more methylglycine diacetic acid (MGDA) salts, of the formula wherein R═CH3 and M is hydrogen, alkali metal, alkaline earth metal, ammonium or substituted ammonium in the appropriate stoechiometric amounts, by a process comprising the steps of i) heating a concentrated slurry comprising methylglycine diacetic acid (MGDA) and/or any salts thereof, the slurry having a solids content in the range of 45% to 70% and suitably in the range from 50% to 70%, and a moisture content of 30% up to 55%, and suitably between 30% and 50%, to a temperature in the range of 50 to 120° C., preferably to about 80° C., and ii) spray granulating said slurry, using an air inlet temperature of 120° C. or less. |
