Uranium mining in Australia Uranium mining in Australia Radioactive ores were first extracted at Radium Hill in 1906, and Mount Painter in South Australia in the 1930s, to recover radium for medical use. Several hundred kilograms of uranium were also produced. Of the world's proven estimated uranium reserves (5,404,000 tonnes), 31% are held in Australia (1,673,000 tonnes), ahead of the second largest, Kazakhstan (12.1% or 651,800 tonnes). In terms of production, Canada is the largest supplier to export markets, followed by Kazakhstan and Australia. Uranium mined in Australia is mainly for export. Australia exported 50,235 tonnes of uranium oxide concentrate in the five years
Period 7 element corresponding to the filling of the 5f electron shell; actinium, a d-block element, is also generally considered an actinide. In comparison with the lanthanides, also mostly f-block elements, the actinides show much more variable valence. Of the actinides, thorium and uranium occur naturally in substantial, primordial, quantities. The radioactive decay of uranium produces transient amounts of actinium, protactinium and plutonium, and atoms of neptunium are occasionally produced from transmutation reactions in uranium ores. The other actinides are purely synthetic elements, although the first six actinides after plutonium would have been produced during the Oklo phenomenon (and long since decayed away),