Gold miner St Barbara is investigating a change in its mining and haulage methods at the historic Gwalia mine in Western Australia.
The company has completed a new life of mine (LoM) plan using existing resources and reserves at Gwalia up to the 2031 financial year.
St Barbara’s new LoM plan proposes a change in mining and haulage methods to reflect the deepening mine and the nature of the existing unmined lodes.
The approach, called Gwalia Mass Extraction (GME), has been forecast to start in the fourth year of the new LoM plan. It will be enabled by the Gwalia Extension Project (GEP) that is currently under construction.
GMX 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.
While the move to GMX is planned within the five-year outlook period, St Barbara is primarily focused on delivering higher production rates and lower unit costs beyond the five-year outlook.
The outlook remains robust without GMX, according to St Barbara. However, the new LoM plan, coupled with the current extension project and ongoing exploration at depth and in the region, indicates that Gwalia will play a pivotal role for St Barbara for the foreseeable future, the company added.
St Barbara managing director Bob Vassie said the $100 million extension project was under way and would start to deliver benefits once the paste aggregate fill (PAF) was commissioned this financial year.
“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,” Vassie said.
St Barbara has launched a GMX feasibility study, which will aim to generate the information it requires for an investment decision by this December.