QUARTERLY REPORT, JANUARY 1, 1960-MARCH 31, 1960

Three methods for the determination of radium were evaluated. In two methods, the radium is finally precipitated with barium sulfate as carrier and alpha-counted. In the other method, the radium is recovered in a carrierfree condition for alpha counting. A method for determining radium by removing interfering elements with solvent extraction technniques and precipitating the radium with barium sulfate is described. A method which gives a rapid estimation of radium isotopic composition in samples, based on precipitation with barium sulfate, conversion to the carbonate, and alpha counting, is described. Flowsheets are contained on all five processes discussed. Two processes for the determination of thorium were evaluated. One method consists essentially of extraction of carrierfree thorium in TTA-benzene, stripped in nitric acid, and direct plating of the nitric acid solution for counting. The second method consists of thorium precipitation on lanthanum hydroxide, then on lanthanum fluoride, dissolution in nitric acid aluminum nitrate, thorium extraction into TTA solution, stripping into nitric acid, and counting. Flowsheets for the processes are given. The effects of pH, sulfate ion concentration, calcium and other contaminants, and temperature on the adsorption of radium from acid leach liquors by barite were studied. Coprecipitation studies of radium with barium sulfate from mill effluent streams were investigated. (For preceding period see WlN-115.) (C.J.G.