Study on a novel flat renewal supported liquid membrane with D2EHPA and hydrogen nitrate for neodymium extraction

The Nd(III) extraction in flat renewal supported liquid membrane (FRSLM), with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in kerosene as the membrane solution, was investigated. The effects of pH in the feed phase, volume ratio of membrane solution to stripping solution, concentration of HNO3 solution and concentration of carrier in the renewal phase on extraction of Nd(III) were also studied, respectively. As a result, the optimum extraction conditions of Nd(III) were obtained when concentration of HNO3 solution was 4.00 mol/L, concentration of D2EHPA was 0.100 mol/L, and volume ratio of membrane solution to stripping solution was 1.00 in the renewal phase, and pH was 4.60 in the feed phase. When initial concentration of Nd(III) was 2.00×10−4 mol/L, the extraction percentage of Nd(III) was up to 92.9% in 75 min.