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 Dial Company Radium Dial Company The Radium Dial Company was one of a few now defunct United States companies, along with the United States Radium Corporation, involved in the painting of clocks, watches and other instrument dials using radioluminescent paint containing radium. The resulting dials are now collectively known as radium dials. The luminous paint used on the dials contained a mixture of phosphorus and radium, a product that the Radium Dial Company named "Luna". However, unlike the US Radium Corporation, Radium Dial Company was specifically set up to only paint dials, no other radium processing took place at the premises. The