Problems in the separation of radium from uranium ore tailings

The radium content of a representative sandstone type of uranium ore was found to be distributed uniformly according to particle size before leaching, but in sulfuric acid-leached tailings was found predominantly in the ?325 mesh fraction. The radium leaching characteristics from both ore and sulfate-leached tailings were investigated. Several 1 M salt solutions showed poor to moderate RaSO₄ dissolution from “slimes solids” tailings, while 3 M HNO₃ or HCl solutions dissolved approximately 95% of the radium content of either ore or tailings. Tests are reported in which ?325 mesh sand particles were coated with alkaline-earth sulfates by a special technique to simulate slime solids tailings. The dissolution of RaSO₄ from these coated sands was decreased by the presence of BaSO₄, but increased by the presence of CaSO₄. The interrelationships in the dissolution of mixtures of CaSO₄, SrSO₄, BaSO₄, and RASO₄ are shown, and a generalized equation for the estimation of the dissolution of a minor component is presented.