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
Uranium trioxide which operates at the world's largest uranium refinery at Blind River, Ontario, produces high-purity uranium trioxide. It has been reported that the corrosion of uranium in a silica rich aqueous solution forms uranium dioxide, uranium trioxide, and coffinite. In pure water, schoepite (UO)O(OH)·12(HO) is formed in the first week and then after four months studtite (UO)O·4(HO) was produced. This alteration of uranium oxide also leads to the formation of metastudtite, Like all hexavalent uranium compounds, UO is hazardous by inhalation, ingestion, and through skin contact. It is a poisonous, slightly radioactive substance, which may cause shortness of breath, coughing, acute