Joint venture (JV) partners AngloGold Ashanti and Independence Group (IGO) have confirmed the technical and financial viability of an underground mine at their Tropicana operation, in Western Australia.
A prefeasibility study into the development of a mine beneath the Boston Shaker pits confirmed that an underground operation could deliver one-million tonnes a year of resources to produce about 100 000 oz/y over seven years.
The project would require an estimated capital investment of A$95-million, 30%-owner IGO said on Thursday.
The underground material will be blended with openpit ore, capitalising on recently completed improvements at the process plant. In late November, a second 6MW ball mill was commissioned, increasing the total throughput rate by about 5% and gold recovery by up to 3%.
“The delivery of Boston Shaker underground will result in an improved grade and gold production profile from Tropicana from the 2021 financial year,” commented IGO MD Peter Bradford.
The JV partners will proceed to a feasibility study, which will incorporate more drilling and the conversion of underground inferred resources into indicated resources. The outcome of the feasibility study is expected towards the end of the third quarter next year.