Westgold Resources Limited provided an operational update from the company's flagship Big Bell mine at Cue in Western Australia. Highlights: Big Bell continues to exceed design outputs - with 100.7kt @ 2.61g/t Au for 8,447oz in January and 90.5kt @ 2.71g/t Au for 7,895oz in February. Drilling results from deeper mine expansion area has exceeded modelled expectations - drilling grades reported in December Quarterly Report exceed current reported Mineral Resource Estimate. Pre-feasibility study (PFS) into Big Bell Deeps expansion advancing - initial stress modelling and mining cost assumption review completed by independent consultancy validates Westgold Scoping Study outputs. Mine design and schedule optimisation phase commences - in parallel with drilling to extend the mine footprint to the north. Big Bell Deeps Expansion Study Update: The 2023 Big Bell Deeps pre-feasibility study (PFS) contemplates options to accelerate development to the deeper portion of the Big Bell orebody (Big Bell Deeps) without impeding 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. Development of the Big Bell Deeps area utilising the existing mining fleet and mine infrastructure provides an expansion path that will decrease the unit cost of mining and increase the overall grade by selectively mining the deeper area. In order to establish this second production front, a change in methodology to Longhole Open Stoping with fill is proposed for the Big Bell Deeps area below the current SLC footprint only. This will ensure that greater grade selectivity is available to Westgold and that the stress regime is able to be adequately managed. The LHOS operation will utilise the same mining fleet, existing decline, escape way, ventilation, power reticulation and pumping infrastructure established for the SLC above it. The LHOS mine design proposes simple extensions to these networks into the LHOS mining zone. Additionally, no material increase to surface support infrastructure or technical and operating personnel over and above current levels which service the SLC are contemplated. A capital infrastructure review is underway. This review is in its infancy, and as such it is inappropriate to provide capital expenditure guidance at this time. However, it is anticipated that aside from ongoing sustaining capital and capital mine development, major infrastructure capital requirement for the expansion plan will be restricted to a paste plant and associated reticulation network. If successful, this addition of LHOS production will move Big Bell output from 800-900ktpa design levels to circa 1.4Mtpa. 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 such as: 38.08m @ 4.22g/t Au from 396m (22BBDD0103) and 64.00m @ 2.62g/t Au from 428m (22BBDD0106), have mineralised widths exceeding the endowment defined by the current Mineral Resource estimate and could enhance economics in this area. Critically, success in its resource definition effort to the north of the current Sub-Level Cave and Expansion Study area may deliver increased tonnage from current mine plans for minimal additional capital, which will enhance the economics of the current caving operation and the expanded Big Bell mine. 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 current financial year.