[en] An investigation was made of the absorption of radium and thorium from waste uranium leach liquor by clays and other materials. Tailings and soil samples from Wyoming and Utah were contacted with tailings liquors to determine the degree of absorption. Absorption ranged from 0 to 99% for radium and from 0 to 31% for thorium. Some samples, which readily absorbed radium, were contacted with various salt solutions that could be present in tailings solutions to determine their effectiveness as desorbents. The desorption of radium ranged from 0.06 to 100%. An alpha-spectrometric method was used to determine the radium and thorium concentrations in the solutions and the solids