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
Depleted uranium Depleted uranium has been used in a number of sampling calorimeters (such as in the D0 and ZEUS detectors) due to its high density and natural radioactivity. Normal functioning of the kidney, brain, liver, heart, and numerous other systems can be affected by uranium exposure because, in addition to being weakly radioactive, uranium is a toxic metal, although less toxic than other heavy metals, such as arsenic and mercury. It is weakly radioactive but is 'persistently' so because of its long half-life. The Agency for Toxic Substances and Disease Registry states that: "to be exposed to radiation from uranium, you