| 摘要 |
<p>A method of crystallizing [S,S]-ethylenediamine-N,N'-disuccinic acid, characterized by regulating an aqueous solution of a metal salt of [S,S]-ethylenediamine-N,N'-disuccinic acid so as to have a temperature of 40 to 80 °C and pH of 1.9 to 4.5 and cooling the solution to 40 °C or lower over 0.2 to 10 hours while feeding a mineral acid so as to maintain the pH at 1.9 to 4.5 to thereby crystallize [S,S]-ethylenediamine-N,N'-disuccinic acid. By this method, crystals of [S,S]-ethylenediamine-N,N'-disuccinic acid which have a bulk density of 0.45 to 1.2 g/cm3 can be obtained in a high yield while inhibiting cyclization during the crystallization.</p> |
