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 King King" was the first vessel to cross Great Slave Lake—arriving in Yellowknife on June 8. While the lake's ice had broken up, it hadn't moved out. Northern Transportation added additional vessels to her fleet, many of which, like the "Radium Charles" and "Radium Yellowknife" also bore the prefix "Radium", and the line was known locally as the "Radium Line". In 1956 the "Radium King" survived the explosion of mining supplies on a barge she was towing. In 1967 the boat was retired. Currently she is on display outside the Northern Life Museum in Fort Smith, Northwest Territories. The "Radium King"