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 dials 186 keV gamma emission 3% of the time. Also, Ra is rarely present without other transuranic elements or decay products, which may emit beta or gamma radiation. Therefore, the radiation hazards from radium paint may not be entirely removed by the varnish, case or container. Care should be taken to prevent the inhalation or ingestion of flakes or dust which may contain radioactive materials. Radium dials have been shown to have dose rates near the face of in excess of 10uSv / hr, which would deliver a dose equivalent to one days background exposure in around 20 minutes. This dose