Bellevue Gold Limited has started the underground decline development at the Tribune portal, part of its namesake mine in Western Australia, employing a new Sandvik DD422iE battery-electric jumbo as part of its production growth strategy.
The Tribune decline milestone is significant because Tribune will provide a second independent mine access route. It will be the sixth independent mining area, which is being developed by an additional fifth jumbo (the Sandvik 422iE). It is expected to access ore from the Tribune lode in the December 2024 quarter.
Bellevue’s Managing Director and Chief Executive Officer, Darren Stralow, said: “The commencement of Tribune is important as it not only provides an additional mining area and haulage decline, but it also creates the platform for commencement of the southern drill drive to target mine life extensions.
“The key infrastructure upgrades are a core part of the Bellevue growth plan and will unlock the ability to achieve the mining rates required for increased production. We are already seeing the benefits of increased ventilation and work areas in our underground mining rates, and the successful dewatering of the old workings unlocks high-grade ore to mine in the upcoming quarters that was previously inaccessible.”
Underground development rates are scheduled to increase over the second half of the company’s 2025 financial year as infrastructure constraints are released and more working areas become available, with the production expected to be back-ended to the second half of the financial year as further development headings and underground advance rates ramp up to a forecast run rate of 1.35 Mt/y by the end of the financial year.
Production guidance for FY25 is 165,000-180,000 oz at a project all-in sustaining cost of A$1,750-1,850/oz ($1,166-1,233/oz) of gold with the production profile weighted towards the second half of this financial year.
The company recently released its five-year growth plan which sees production forecast to ramp up to more than 200,000 oz/y run rate from the last quarter of that financial year before reaching circa-250,000 oz/y in the 2028 financial year.
The ramp up of underground tonnages continues to advance with the key ventilation upgrade in construction and commissioning due to commence on September 18, 2024. The ventilation upgrade will initially increase underground vent flows by 50% and will provide fit-for-purpose vent fans suitable for the life of mine, Bellevue says. Historic mine dewatering has also reached a significant milestone with the dewatering of the old workings now allowing for the removal of the safety exclusion zone from the historic underground. This will unlock mining of high-grade development and stoping in the Armand mining area.
These two key infrastructure works are expected to assist in de-bottlenecking the underground and allow more efficient use of the mining fleet.
The addition of a Sandvik DD422iE battery-electric vehicle, which trams on battery and plugs into the mine’s captive power infrastructure during drilling operations, demonstrates Bellevue’s commitment to electrification of the mining fleet where practical, the company says.
The Sandvik DD422iE is an electric development jumbo designed to drive down production costs while reducing the environmental impacts of drilling and tunnelling. By using electric energy from an onboard battery during tramming, Sandvik DD422iE produces zero emissions while manoeuvring between headings, the OEM says. This improves health and safety for miners working underground. Less diesel usage in a mine thanks to diesel-free drilling can ease ventilation requirements, while also reducing associated diesel logistics and maintenance expenses. Using a mine’s existing electric infrastructure, the Sandvik driveline technology enables the battery to recharge during the drilling cycle. The battery will even recharge while Sandvik DD422iE is tramming downhill, using energy generated by the braking system.