Solvent extraction of Nd(III) in a Y type microchannel with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester

• Main Authors: Zhang Libo, Xie Feng, Li Shiwei, Yin Shaohua, Peng Jinhui, Ju Shaohua
• Format: Article
• Language: English
• Published: De Gruyter 2015-01-01
• Series: Green Processing and Synthesis
• Subjects: microreactor; nd(iii); p507 extractant; solvent extraction
• Online Access: https://doi.org/10.1515/gps-2014-0095

Conventional extraction equipment has many problems like a long mixing time, a large factory area occupation, a large amount of organic solvent consumption and so on. In this paper, a micro solvent extraction system for the extraction of Nd(III) was investigated to solve the above issues. The initial aqueous pH 4.0 and saponification rate 40% of 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (P507) were selected as the optimal experimental conditions. The extraction equilibrium was quickly achieved within 1.5 s, without any mechanical mixing in a narrow channel (100 μm in width and 120 μm in depth) at a volumetric flow rate from 5.55×10-10 m3/s to 1.53×10-9 m3/s. The extraction behavior of Nd(III) in the microreactor is an interface chemical reaction or the diffusion rate of the Nd-complex in the organic phase at low pH and [P507], while the extraction rate is controlled by the rate of metal diffusion in the aqueous phase at high pH and [P507], and the apparent mass transfer rate is up to 3.29×10-5 mol/m2·s. The extracted complexes are determined by the infrared (IR) spectrum method, and confirm that the extraction is via a cation exchange mechanism in the microreactor.