Separation of traces of calcium from thorium on Zeocarb 226 and Dowex A-1

Ion exchange methods of separation of traces of Ca from Th employing Zeokarb 226(H+) and Dowex A-1(H+) have been developed. In the case of Zeokarb 226, a small fraction of Ca2+, under conditions of negligible Ksub(d) value, is strongly held on the column. This is prevented by the presence of excess La3+, Al3+ or o-phenanthroline. On Dowex A-1 the breakthrough capacity of thorium is greater at pH 1.0 than at pH 2.0 in sulphate medium, contrary to the order of Ksub(d) values. (author)