磷酸二氢铵的提纯工艺研究

Purification of ammonium dihydrogen phosphate

研究了用离子交换法提纯磷酸二氢铵的方法。以树脂的三价铁离子、二价钴离子、二价镍离子、二价铜离子吸附容量和再生性能为考查指标，从3种树脂中选出了性能最佳的一种——亚氨基二乙酸螯合树脂D401，并探讨了溶液pH、温度等因素对该树脂吸附容量的影响。结果表明提纯磷酸二氢铵的最佳条件为：pH4．0～4．5，温度30～40℃。在该实验条件下，D401可将分析纯磷酸二氢铵中三价铁离子、二价钴离子、二价镍离子、二价铜离子的总质量分数降至2．3×10^-6。

The purification of ammonium dihydrogen phosphate by ion exchange method was studied. Based on the load- ing capacity （on Fe3^＋ ,Co2^＋ , Ni2^＋ and Cu2^＋ ）and reproducing property,the iminodiacetic acid chelating resin D401 was selected as the best one from three kinds of ion exchange resin. The factors, such as solution＇s pH value and temperature etc. that can exert effects on the properties of D401 ,were investigated. Results showed that the optimum conditions for purification of NH4 H2 PO4 are： pH 4.0 - 4.5 and temperature 30 ～ 40℃. Under these conditions, the total mass fraction of Fe3^＋ , Co2^＋ ,Ni2^＋ and Cu2^＋ can be reduced to 2.3 × 10-6 min the analytically pure ammonium dihydrogen phosphate.