Recovery of europium from a rare earth chloride solution

Abstract

A two-stage Jones reductor column has been applied to the separation and purification of europium from a commercial rare earth chloride solution. The process consists of the reduction of Eu(III) to Eu(II) by a zinc amalgam, followed by the precipitation of europium(II) sulphate (EuSO 4) in an inert atmosphere (CO 2). Variables such as acidity, concentration and flow rate of the rare earth chloride solution in the Jones column, mercury concentration in the zinc amalgam, concentration of the precipitating agent (sulphuric acid), and the inert gas flow rate, have been evaluated with a pure europium synthetic solution. Based on the results, the experimental conditions have been adjusted to recover europium from a commercial rare earth solution, containing 2.4 g l −1 Eu 2O 3, 114.4 g l −1 Sm 2O 3 and 64.2 g l −1 Gd 2O 3 as the main constituents. The final product, assaying 99.4% Eu 2O 3, was obtained with a recovery of 92%.