EXTRACTION METHOD FOR THE SEPARATION OF EUROPIUM (III) AND YTTRIUM (III) FROM LUMINOPHORES DUST AND SLUDGE

摘要

The invention relates to a method of selective extraction of europium(III) and/or yttrium(III) ions from luminophore dust or sludge, the major components of which are oxides and sulphides of zinc, cadmium, yttrium and europium. From the concentrate of luminophore dust or sludge an aqueous solution is prepared and is subsequently contacted with an extraction agent, which is alkylphosphoric or dialkylphosphoric acid, either pure or diluted with an organic solvent. The reaction equilibrium is strongly dependent on the equilibrium concentration of free acid in the aqueous phase of the reaction. After separating the aqueous phase and the organic phase after the extraction, europium(III) and yttrium(III) ions are recovered from the organic phase.