| 摘要 |
The invention relates to a method for isolating methyl glycine nitrile-N,N-diacetonitriles (MGDN) from an MGDN-containing aqueous emulsion with an MGDN content of 3-50% by weight in a crystallizer. The inventive method is characterized by (a) cooling the aqueous emulsion, starting from a temperature above the solidification point, to a temperature below the solidification point, the cooling rate in the temporal mean not exceeding 5K/h, until substantially the total amount of the emulsified MGDN has solidified; and (b) continuing to cool the aqueous suspension obtained and/or concentrating it, the cooling rate being higher than that in step (a). |
