The St Barbara board has approved funding for the Gwalia extension project, that will extend mining at the gold operations to at least 2000m below the surface (mbs) in 2024.
The extension project, with a $100 million budget, will take between two and a half and three years to construct at Gwalia operations located south of Leonora in Western Australia. It consists of two main components: a ventilation upgrade and paste aggregate fill (PAF).
The additional ventilation will come through raise bore intake and exhaust ventilation shafts as well as associated power and cooling infrastructure needed to mine between 1800 and 2000mbs.
The PAF, which is set to be completed within 12 months, involves mixing paste from surface with waste rock crushed underground for stope fill. By disposing waste underground, truck and ventilation resources are able to focus on ore production, increasing efficiency and production. It also enables faster stope filling and reduces stope cycle times.
The extension project is also expected to generate a higher financial return and increase the potential for further extensions.
In January this year, the board approved $6 million project readiness and early works funding for the March 2017 quarter which included engineering, hiring project staff, contacting vendors and beginning underground works. These works are also included in the $100 million budget.
If the drilling program finds major resources deeper than 2000mbs, the feasibility study indicates additional infrastructure that could extend ventilation from 2000mbs to enable mining at 2200mbs.
St Barbara managing director and CEO, Bob Vassie, said the extension project’s approval begins a new phase in Gwalia mine’s history.
“Gwalia started in 1896 and it just keeps going,” he said.
“The project will ensure Gwalia can continue delivering strong, high margin gold production until at least 2024, with the foundation laid for further extensions to the mine life beyond this, as well as potential for increased production.”