鉱物処理

[1308-17-10] Recovery of Rare Earth Elements from Aqueous Solution Using Combination Process of Solvent Extraction and Precipitation

○Ariuntuya Battsengel¹, Altansukh Batnasan¹, Kazutoshi Haga¹, Atsushi Shibayama¹ (1. Akita University)

司会：三木 一（九州大学）

Keywords:Rare Earth Elements, Solvent Extraction, D2EHPA & PC88A, Precipitation

Different separation techniques such as solvent extraction, ion exchange and precipitation are often used for recovery of rare earth elements (REEs) from pregnant leach solutions obtained from the acid leaching. Solvent extraction is generally accepted as the most appropriate commercial technology for separating rare earth elements due to the need to be able to handle larger volumes of dilute pregnant liquors.

This paper presents the results of laboratory studies for the recovery of rare earth elements from pregnant leach solution using solvent extraction followed by a selective stripping and precipitation processes. Effect of extractability of REEs from different kind of aqueous (H₂SO₄, HCl & HNO₃) media obtained from apatite leaching were investigated by solvent extraction techniques with comparison of two extractant systems of D2EHPA & PC88A. The influences of processing parameters such as concentration of organophosphorus acids, organic/aqueous phase ratio, the effects of pH for solvent extraction and precipitation were investigated. The role of organophosphorus extractants for extraction and separation of light and heavy REEs were discussed.