JOHANNESBURG (miningweekly.com) – Gold miner St Barbara is studying a change in mining and haulage at the Gwalia mine, in Western Australia, to better suit the orebody as the mine deepens.
The new mining method essentially involves a move to “island pillar” methods for narrower lodes with increased mining rates, and matching that with increased haulage rates by moving to hydraulic hoisting.
Announcing the outcomes of the prefeasibility study as part of a medium- and long-term outlook for the Gwalia mine, St Barbara said on Wednesday that the results were encouraging and indicated an opportunity to convert more of the existing mineral resources into mineable ore reserves by increasing mining rates, reducing unit costs and using the existing mill capacity.
The new mining approach, termed Gwalia Mass Extraction (GMX), is assumed to begin in year four, or the 2021 financial year, of a recently completed life-of-mine plan for the operation, which extended the life of Gwalia to 2031, using existing resources and reserves.
A feasibility study of GMX has started and St Barbara said that it aimed to make an investment decision in December this year.
GMX is enabled by the A$100-million Gwalia Extension Project that is currently under construction.
“The adoption of a new approach to mining our orebody will allow the mine to continue strongly past the five-year outlook period, such that Gwalia will continue to be the cornerstone asset for the company and provide us with a stable foundation on which to pursue value-adding growth initiatives,” St Barbara MD and CEO Bob Vassie commented.