Study on separation technology of Pr and Nd in D2EHPA-HCl-LA coordination extraction system

The separation coefficient of Nd/Pr was lower in D2EHPA-HCl system. Pointing to this problem, the effect of the acidity of feed and the concentration of lactic acid on the distribution ratio, separation coefficient and extraction capacity was investigated in unsaponified D2EHPA-HCl-LA system, and the regression equations were calculated in this paper. The results showed that the distribution ratio and separation coefficient both increased with decreasing of feed acidity and increasing of the lactic acid concentration, and the extraction capacity increased with increasing of lactic acid concentration in D2EHPA-HCl-LA system. When the pH value of the feed was 3.5 and lactic acid concentration was 0.6 mol/L, the max separation coefficient was 1.57, and the extraction capacity was 27.87 g/L.