S. A Shama,.1, M. H Shalaby.2, M. S. Abd El-Ghan2 and M. E. El-Awady2 1Faculty of Science, Benha University, Egypt. 2Nuclear Materials Authority, Cairo, Egypt Summary. Sulphate effluent solutions from anion exchange resin after uranium extraction were containing about 115 ppm of rare earth elements (REE), so a trial to recover these amounts was studied. Precipitation of rare earths from these solutions using sodium hydroxide was firstly studied to prepare hydrous cake concentrate followed by studying upgrading for this concentrate by selective precipitation from different acidic media using hydrofluoric or oxalic acids. More than 99% of the REE were precipitated from the effluent solutions using sodium hydroxide at pH 8.5 while the same precipitation efficiency was achieved at lower pH value (6.5) in presence of 2.5% hydrogen peroxide. However, it is benefit to firstly precipitate most of the iron cations at pH 3.0 also washing the produced REE hydroxide cake by water of pH 9.5 to decrease the co-precipitated aluminum as well as upgrading the constituents of REE in the cake from 16% to more than 27%. Rare earths selective precipitation using hydrofluoric acid from nitrate medium was the most effective while the precipitation using oxalic acid from hydrochloric acid medium was effective where about 98% precipitation efficiency were achieved in the two cases. On the other hand, the rare earths fluoride precipitate was high grade and containing minimum co-precipitated of the other constituents than that of rare earths oxalate. |
