鉱物処理

[1308-17-10] 溶媒抽出と沈殿法を組み合わせた水溶液からのレアアース回収

○バトセンゲル アルゥン トゥヤ¹、ﾊﾞﾄﾅｻﾝ ｱﾙﾀﾝｽｯｸ¹、芳賀 一寿¹、柴山 敦¹ (1. 秋田大学)

司会：三木 一（九州大学）

キーワード：レアアース、溶媒抽出、D2EHPA & PC88A、沈殿法

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.