Horseshoe Metals has outlined a substantially larger conceptual open pit at Horseshoe Lights, containing 95,033 tonnes of copper under a A$25,000-per-tonne price assumption. The result supports further studies, but does not yet establish an Ore Reserve or a development case.
- 12.34 million tonnes at 0.77% copper in the headline pit optimisation
- 95,033 tonnes of contained copper, 71% above the 2014 optimisation
- A$25,000 per tonne copper price used in the updated assumptions
- Scoping work to examine DSO, oxide heap leaching and sulphide flotation
- Exploration Target remains conceptual and requires further drilling
Larger pit shell captures 95,033 tonnes of copper
Horseshoe Metals Ltd (ASX:HOR) has more than doubled the scale of the pit outlined in its earlier Horseshoe Lights study, with a new optimisation covering the Main Zone and Motters Zone in Western Australia. The company says the single open pit contains 12,337,226 tonnes at 0.77% copper, equivalent to 95,033 tonnes of contained metal, and extends to a maximum depth of 260 metres in the Main Zone.
That is 71% more contained copper than the 2014 optimisation, which contemplated 5.99 million tonnes at 0.93% copper for 55,700 tonnes of contained copper. The comparison is not like-for-like: the new exercise uses a copper price of A$25,000 per tonne, against A$9,925 per tonne in the earlier study, alongside updated mining, processing and operating assumptions.
The announcement contains one numerical inconsistency that the company may need to clarify. The headline, optimisation summary and key results state 12,337,226 tonnes, while Table 3 reports a total of 13,337,726 tonnes. That difference does not alter the reported 95,033 tonnes of contained copper, but it matters for any investor trying to assess the scale of the proposed mining inventory.
High copper price supports further development studies
Horseshoe says the optimisation was designed to demonstrate “reasonable prospects for eventual economic extraction” under the 2012 JORC Code and provide a platform for scoping and mining studies. It is not a feasibility study, does not establish an Ore Reserve and does not present project-level cash flow, capital costs or a production schedule.
The model assumes 15% mining dilution, 90% mining recovery, an 80% payable copper factor, a five-to-one strip ratio and processing at 1 million tonnes per annum. Oxide and transitional material is assumed to achieve 80% recovery, with fresh material at 85%. Gold and silver in the oxide and transitional material were assigned no value in the optimisation, leaving those potential credits outside the headline result.
The pit contains 1.14 million tonnes of oxide, 2.18 million tonnes of transitional material and 9.02 million tonnes of fresh material in the company’s material breakdown. Horseshoe says most of the North Dump and a significant part of the eastern side of the Northwest Dump would be removed under the modelled pit and buffer zone, with mineralised material in the North Dump potentially feeding an early oxide heap-leach operation.
DSO sales and staged processing remain the near-term test
The broader development concept is deliberately staged. Horseshoe plans to assess additional Direct Shipping Ore production or ore sorting from stockpiles, oxide heap leaching of surface and near-surface material, and later flotation treatment for transitional and sulphide ore. The company is also preparing to report XRF and check-assay results from DSO sampling as it pursues multiple sales channels.
That near-term focus follows the company’s planned DSO sales batches, which were linked to potential 500-tonne shipments and non-binding offtake proposals. The new pit work gives those stockpile activities a larger development narrative, but the announcement does not say that DSO revenue has yet funded the proposed studies or established commercial production.
Exploration Target still needs drilling before resource conversion
At depth and along strike, Horseshoe is relying on an Exploration Target of 20 million to 30 million tonnes at 0.7% to 1.2% copper for the Main Zone and 2.6 million to 3.6 million tonnes at 1.0% to 1.5% copper for Motters. The company says modelling supports continuity from 200 to 600 metres below surface at Main Zone and from 80 to 300 metres at Motters, building on the previously disclosed 20-30Mt Main Zone target.
Those figures remain conceptual. Horseshoe expressly cautions that there has been insufficient exploration to estimate a Mineral Resource and that further drilling may not produce one. Phase 2 drilling at Motters is planned to restart this quarter, alongside Main Zone extension drilling, additional metallurgical work and an update of the 2014 scoping study at current and projected copper prices.
Bottom Line?
The pit optimisation has improved the scale of the development story, but the next value test is whether drilling, metallurgy and a revised scoping study can convert a high-price conceptual shell into a financeable staged operation.
Questions in the middle?
- How sensitive is the 95,033-tonne copper inventory to lower copper prices, higher costs, recoveries and the five-to-one strip ratio?
- Will Motters and Main Zone drilling convert enough of the Exploration Target into a JORC Mineral Resource to support a larger mine plan?
- Can DSO sales and oxide test work provide a credible early funding pathway before the sulphide processing case is defined?