Isolation of rare earth elements from ammonium salts solutions

Abstract

It has been shown that nonradioactive concentrate containing up to 97–99 wt % rare earth elements (REEs) oxides after calcinations might be isolated from the strippant based on concentrated aqueous solution (275–300 g/L) of ammonium sulfate or ammonium nitrate obtained during the REE extraction from phosphogypsum or phosphoric acid. A REE loss in thorium-containing precipitate does not exceed 0.1–0.5% in the hydrolytic precipitation of thorium.