Radium of radium Curie used the residues after extraction of uranium from pitchblende. The uranium had been extracted by dissolution in sulfuric acid leaving radium sulfate, which is similar to barium sulfate but even less soluble in the residues. The residues also contained rather substantial amounts of barium sulfate which thus acted as a carrier for the radium sulfate. The first steps of the radium extraction process involved boiling with sodium hydroxide followed by hydrochloric acid treatment to remove as much as possible of other compounds. The remaining residue was then treated with sodium carbonate to convert the barium sulfate into
Radium Hill the Radium and Rare Earth Treatment Company N.L. which continued operations there until 1931. The company also built a treatment plant in 1923 at Dry Creek near Adelaide to produce radium bromide for medical applications from the Radium Hill ore, however this proved to be uneconomic and both sites had ceased operations by 1932. Activity recommenced after World War II, with a Department of Mines geological survey in 1944 and exploration and drilling work done in 1946-1947. In March 1952 the Commonwealth and the South Australian governments signed a cost plus uranium supply contract with the UK-USA Combined Development Agency,