Broken Hill Mines (ASX: BHM) is preparing to ramp-up mining and processing activities at the high-grade Main Lode within the Blackwoods underground silver-lead-zinc ore body at its Rasp silver mine in New South Wales.
Production commenced in October to supplement and upgrade feed ore from the Western Min ore body, which lies in the large, historical Line of Lode deposit.
All approvals for a ramp-up from development to stoping operations have been granted and processing has delivered metallurgical recoveries above 88% for lead and zinc and 75% for silver.
Best Main Lode Assays
Recent drilling at Main Lode returned best intercepts of 3 metres at 1,426 grams per tonne silver equivalent (AgEq) and 37.2m at 314g/t AgEq, outside of Blackwood’s existing mineral resource estimate of 670,000t at 18.7% zinc equivalent (ZnEq) and 628g/t AgEq (141g/t silver, 7.4% lead, and 8% zinc).
Broken Hill remains on target to launch an expanded 17,000m drilling program in the new year to extend the Main Lode resource, and expects the processing of Blackwoods ore to increase the grade of silver within the lead concentrate to between 1,000g/t and 1,200g/t.
The current strong upward revaluation for silver means its contribution to the overall economic value of the Main Lode deposits has materially increased compared to other metals, while the company intends to also conduct a systematic series of gold assays at Rasp in the coming months.
Virgin Stoping Potential
As the first deposit of the Main Lode resource, Blackwoods provides virgin stoping potential in good ground with additional remnant mining opportunities outside the current resource estimate.
The company has drilled six holes to date across Blackwoods and the neighbouring Thompsons and British ore bodies to test extension possibilities.
Best assays include 3m at 51.5% ZnEq and 1,426g/t AgEq (483g/t silver, 18.5% lead, 19.7% zinc, and 0.2% copper), and 5.1m at 21.1% ZnEq and 591g/t AgEq (146g/t silver, 7.6% lead, 9.5% zinc and 0.1% copper).
Continued expansion of Main Lode operations and the initiation of first mining activities at the Pinnacles mine, southwest of Rasp, are key initiatives of Broken Hill’s strategy to utilise Rasp’s 750,000 tonnes per annum processing plant over the next 12 months.
Broken Hill is targeting the release of an updated MRE for Rasp in H1 CY26.
