AngloGold Ashanti Ltd. and Independence Group NL approved the first phase of the Long Island strategy for the 70/30 Tropicana joint venture, which will increase mine life by about seven years to 2027.
The entire strategy will add 2.1 million ounces to Tropicana's business plan, AngloGold said Dec. 7.
The first stage includes mining the Havana South pit and a cutback of the Boston Shaker pit, which will use the completed Tropicana pit as the first backfill location.
The venture now also plans to upgrade the processing plant, adding a second ball mill to increase mining rate to 8.1 million tonnes per annum and improve gold recovery to about 92%.
Total capital expenditure is expected at A$28 million including equipment, construction cost and spares, with the new mill to be commissioned in the December 2018 quarter, Independence said in a separate Dec. 7 release.
Gold production from the Tropicana mine is expected between 478,000 and 492,000 ounces in 2018 and between 530,000 and 548,000 ounces in 2019.
Mining costs at the venture are expected to reduce 5% to 10% during the first phase, from the current A$3.07 per tonne.
Capital expenditure at Long Island for expansion of site infrastructure, including accommodation and workshops, is estimated at about A$18 million.
During its remaining mine life, Tropicana is estimated to produce about 4 million ounces of gold, excluding potential output from underground mining at the Boston Shaker ore body.
A pre-feasibility study on underground mining will be commissioned in 2018.
The ore reserve increased 830,000 ounces, excluding depletion, over the past 12 months to 66.6 million tonnes at 1.91 g/t of gold for 4.1 million ounces.
In August, AngloGold lifted the throughput at the Tropicana processing plant to 7.5 million tonnes per annum, from nameplate capacity of 5.5 mtpa.