Selective Precipitation of Yttrium From Monazite Acid Leach Liquor by Using Carbonates Precipitation Method.

Abstract

Rare earth elements (REE) solubility with carbonate salts vary greatly from element to element. The heavy rare earth elements (HRE) being more soluble than the light rare earth elements. Their solubility is a function of the carbonate concentration and the kind of carbonate as sodium, potassium and ammonium. In this work, it is explored the ability of the carbonate for the precipitation of the REE and an easy separation of yttrium was achieved using sodium carbonate to form complex yttrium carbonate followed by oxalic acid precipitation. Form this work REEs concentrate containing (%)1.8 Y2O3, 1.6 Gd2O3, 23.4 CeO2, 7.6 Nd2O3, 11.4 La2O3, 2.3 Sm2O3, 0.8 Eu2O3 and 3.1 Pr6O11, where the mentioned concentrate was produced after the acid treatment of monazite mineral followed by dissolution with ice water. The produced solution was precipitated with sodium carbonate followed by dissolution in hydrochloric acid and precipitation using oxalic acid to produce yttrium concentrate containing 54.86% Y2O3, 15.53% CeO2, 15.29% La2O3 and 6.90% Nd2O3.