The Tropicana Mine, the first greenfields gold discovery to be brought into production in Australia for more than a decade, poured first gold on September 26, 2013, ahead of schedule and on budget.
Innovation has been incorporated into the design of Tropicana’s mining and processing systems, from the start of exploration through to environmental management and closure planning.
Open pit mining utilises conventional drill and blast methods. Over the life of the mine four pits – the Tropicana, Havana, Boston Shaker and Havana South pits will be mined in several stages. The pits will stretch over a length of 5 kilometres and a width of 1.2 km. The life of mine stripping ratio will be 5.5:1.
Mining is carried out by Macmahon Holdings using a fleet of Caterpillar equipment. Caterpillar MineStar technology supports automated dispatch of haul trucks and GPS-guided drilling and excavation for precision mining.
The processing plant has a design throughput rate of 5.8 million tonnes per annum and is based on a comminution circuit comprising two-stage crushing, High Pressure Grinding Roll (HPGR) and ball milling, along with a conventional CIL circuit.
The average gold recovery is forecast to be 90%.
Power for the processing plant, and the accommodation village and administration facilities comes from a diesel-fired power plant.
However, in July 2014 AGAA signed agreements with a natural gas infrastructure company for the transportation of natural gas to Tropicana as well as its 100%-owned Sunrise Dam mine. It is expected that this will provide continuity of fuel supply, reduce exposure to diesel price volatility and significantly reduce the number of trucks on the site access roads. Construction started in March 2015 and first gas is scheduled to be available at Tropicana in January 2016.
In 2014 the mine produced 510,000 oz at a total cash cost of US$545/oz and in 2015 is forecast to produce between 470,000-500,000 ounces at total cash costs of US$560-$630/oz and AISC of US$770-$790,000/oz. This was based on Ore Reserves at the end of December 2014 of 3.20 million oz (see Reserve & Resource statement for the full details and applicable JORC disclosures). LOM production will be 3.6 million ounces over an 11 year mine life. This equates to average annual production of between 330,000-350,000 ounces. The average head grade will be 2.01 grams/tonne.
A conceptual mining study is being carried out to consider an alternative, low-cost approach to mining the down dip extensions of the Havana and Tropicana open pits, along with extensions to the north and south.
The mining study is looking at the application of mine design techniques that are used more commonly in mining other commodities, such as coal.
Later in 2015 the mine will pour its one millionth ounce.
Work is also being undertaken to optimise the 5.8 Mtpa processing plant which is capable of working at about 6.5 Mtpa. A debottlenecking study is being carried out, with a view to increasing throughput to between 7-7.5 Mtpa, through staged increases.
Annual production is likely to be maintained at about 400,000 ozpa.