A Study on Anion Exchange aud Amine Extraction of Rare Earth Elements in Nitric Acid

Abstract

The amine extraction of rare earth elements in nitric acid is compared with anion exchange and TBP extraction with respect to the increase or decrease in Kd value with increasing atomic number of rare earth elements. Concerning the relationship between distribution coefficient and atomic number of rare earth element, a similar trend is observed in anion exchange and amine extraction. The distribution coefficient decreases with increase in the atomic number. In TBP extraction, however, the corresponding value increases with increasing atomic number. It seems that the mechanism of amine extraction for rare earth element is similar to that of anion exchange.

Solvent Extraction of Inorganic Species.

“…The extractability of pentavalent neptunium is negligible (441), but that of protactinium is relatively high (163,193); nevertheless it may be separated easily from the tetravalent actinides which are extracted extremely well. Trivalent actinides and lanthanides show only very small distribution coefficients between amine solutions and nitric acid (135,162), but much higher ones with lithium nitrate solutions (246,248). The spectra of tervalent plutonium, samarium and erbium in the organic solutions are similar to those in concentrated lithium nitrate solutions (248).…”

The Coordination Chemistry of Yttrium and the Rare Earth Metal Ions

“…Amine extraction of nitric acid solutions of rare earth metal ions has been investigated and found to be mechanistically more similar to anion exchange than to tributyl phosphate extraction (245). Amine extraction has been applied to the separation of the actinides from the lanthanides (378).…”

Recovery of yttrium and neodymium from copper pregnant leach solutions by solvent extraction

“…Research has been conducted which shows the success of Primene JM-T as an extractant for the recovery of trivalent rare earths. The research by Ichikawa (1961) shows the process of anion exchange and the use of amines in the extraction of rare earth elements in nitric acid. For the anion exchange process Dowex 1, X8 (100~200) mesh was used as the anion exchange resin.…”