Olympic dam

The BHP Billiton Olympic Dam underground mine and processing plant at Roxby Downs in South Australia is located 560 kilometres north west of Adelaide. It is primarily a copper mine that also produces uranium, gold and silver.

Olympic Dam Mine Began Operations in 1988
The large copper deposit at Roxby Downs was discovered in 1975 leading
to the Olympic Dam mine being opened in 1988 by Western Mining Corporation (WMC Resources). WMC Resources was de-listed from the Australian Securities Exchange (ASX) in June 2005 after it was taken over by BHP Billiton. Along with the mine and its infrastructure, BHP Billiton also inherited a licence to continue mining operations at the site until 2036 that can be extended for a further 50 years.

McMahon Awarded big Olympic Dam Contract
Mining contractor, McMahon, have the contract to undertake underground mining at the Olympic Dam Mine on behalf of BHP Billiton. The initial contract between McMahon and BHP Billiton required over 10,000 metres of underground mining development that included all the associated work involved. This was later extended to 33 kilometres of underground lateral development that involved ground support. In 2011 McMahon was awarded a further three year contract that could be extended to four years, if required, to undertake further underground mine development. This included cablebolting, shotcreting and all other associated work along with a further 35,000 metres of lateral underground development.

Olympic Dam is the Largest Underground Mine in Australia
The Olympic Dam operation is a very large polymetallic undertaking with probable and proven copper ore reserves totalling 717 million tonnes, grading at 1.7 percent copper and 0.5 kilogram a tonne of uranium oxide. It is the largest known uranium ore body in the world, the fifth largest gold ore body and the sixth largest copper deposit. It is the largest underground mine in Australia.

Expansion Program put on Hold
It was announced in 2007 that BHP Billiton planned considerable expansion of the Olympic Dam mining operation, however, this was put on hold in late 2012 owning to a world slump in commodity prices. The company is still looking at alternatives that are less costly to put into practice and more in line with the expected demand in the future. This could include developing an open pit expansion to improve its copper production that would be able to incorporate new mining technology. The South Australian government has agreed to give BHP Billiton until 2016 before it will have to proceed with any planned expansion at the Olympic Dam Mine otherwise it will have to go through a whole new approval process.

Processing Plant at the Olympic Dam Mine is ìState of Artî
The processing plant at the Olympic Dam Mine consists of gold, copper and silver refineries, a sulphuric acid plant, a copper smelter, a hydrometallurgical plant and a copper concentrator. In recent times a Svendala autogenous mill has been added along with extra electro-refining cells, a anode furnace gas-cleaning facility, an electric slag cleaning furnace, two counter-current decantation thickeners and additions to the flotation section.

Copper is recovered by means of copper sulphide flotation from slurry prior to the copper being smelted and put through electro-refining to become a pure copper product. The waste from the electro-refining process is further treated to recover silver and gold. After flotation takes place the crushed ore is leached with sulphuric acid in order to dissolve uranium. The uranium is converted into calcined uranium oxide and yellowcake.
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