Europium separation from a middle rare earths concentrate derived from Egyptian black sand monazite

摘要

Europium separation from a middle rare earth concentrate has been achieved successfully by using the combined chemical reduction-precipitation technique. The separation method depends on the reduction of europium by metallic zinc to its bivalent oxidation state followed by selective precipitation of the sparingly soluble europium (II) sulphate, while leaving the other rare earth sulphates in solution. This process consists of two steps; the first is reduction, which involves passing europium (III) chloride solution through a column packed with zinc particles. The other step involves the precipitation of the produced europium (II) chloride using a sulphate salt under inert atmosphere. Variables such as column dimensions, acidity, europium concentration in feed solution, contact time, ageing time, and concentration of the precipitating agent, have been evaluated with a pure europium synthetic solution. Based on the obtained results, a separation process was suggested for the separation of europium from a middle rare earth concentrate extracted from an Egyptian beach sand monazite. The result of this working-up is a europium yield of about 91 percent of the amount employed with a purity of about 97 percent.