Westgold Resources has provided an operational update for its flagship Big Bell mine at Cue, Western Australia.
The update shows Big Bell continues to exceed design outputs with 100.7kt at 2.61g/t gold (Au) for 8,447oz in January 2023, and 90.5kt at 2.71g/t Au for 7,895oz in February 2023.
Drilling results from deeper mine expansion areas have exceeded modelled expectations, with drilling grades reported in the December Quarterly Report (released 24 January 2023) exceeding the current reported Mineral Resource Estimate.
The mine design and schedule optimisation phase is due to commence, in parallel with drilling to extend the mine footprint to the north.
The pre-feasibility study (PFS) into Big Bell Deeps expansion, completed by independent consultancy, validates Westgold Scoping Study outputs.
The 2023 Big Bell Deeps PFS proposes options to accelerate development to the deeper portion of the Big Bell orebody while maintaining productivity from the current sub-level cave operation.
This opportunity has become possible due to increased operational efficiencies in the cave and greater geological understanding at depth.
Technical studies completed to date have considered many innovative approaches to how best to maximise output at Big Bell in the longer term.
A capital infrastructure review is also underway. This review is in its infancy, and as such it is capital expenditure guidance cannot be provided at this time. However, it is anticipated that aside from ongoing sustaining capital and capital mine development, major infrastructure capital requirements for the expansion plan will be restricted to a paste plant and associated reticulation network.
Resource Extension Drilling Continues
In parallel with the PFS, resource development drilling into the expansion area is progressing, with a goal of providing data with adequate granularity to allow a Big Bell Expansion Final Investment Decision to proceed with certainty. This drilling is expected to continue for several months, prior to transitioning to grade control works upon receipt of a positive Final Investment Decision.
Encouragingly results to date indicate that the orebody is consistent with modelled assumptions, however several holes have mineralised widths exceeding the endowment defined by the current Mineral Resource estimate and could enhance economics in this area, including:
- 38.08m at 4.22g/t Au from 396m
- 64.00m at 2.62g/t Au from 428m
Looking Forward
With broad-scale geotechnical stress modelling and mining cost assumptions confirmed, work is now ongoing on paste fill test-work, and optimising mine designs and subsequent schedules.
Capital review and resource drilling continues with the PFS scheduled to be presented to the Westgold Board in the final quarter of the 2022-23 financial year.
Feature image: Worker in underground mine. Image: Westgold.
