Radiochemical studies in chemical separation and spectrographic determination of rare earths in thorium oxide matrix (Preprint No. RA.06)

A chemical separation procedure was standardised for the separation of traces of rare earths from ThO2 matrix using HDEHP (Di 2-ethyl hexyl phosphoric acid). The studies were carried out using both nitric acid and hydrochloric acid medium in different concentrations. The extraction studies were also carried out using radioactive isotopes of rare earths viz. 141Ce, 152-154Eu, 153Gd, 170Tm etc. The extraction was effective in both media. In 0.1 M HDEHP/xylene and 3 M HNO3, Ce was partially extracted into organic phase. So HCl/xylene medium was chosen for extraction purposes. The recovery was confirmed by both gamma counting and emission spectropgraphic method. It was found to be quantitative within experimental error. The separation procedure development here was used for determination of rare earths in thorium oxide matrix by emission spectrographic method. (author)