The 21-hole reverse circulation drill program returned assays such as 5m grading 10.3g/t gold (MDRC931) as well as 28m at 1.54g/t from 171m and 20m at 1.54g/t from 129m (MDRC949) that demonstrated the continuity of mineralisation across the three drill lines.

These results confirm the resource model, prompting Astral Resources (ASX:AAR) to note that it would likely upgrade inferred resources in the drilled 280m by 60m area to the higher confidence indicated category.

This will in turn support the inclusion of Iris, which currently has a resource of 4.4Mt at 0.8g/t for 115,000oz of contained gold, into the Mandilla PFS that is due for completion in Q2 2025.

It also led the company to start planning for further infill drilling during 2025 to increase the drill density for the rest of the Iris deposit.

Separately, AAR has completed a 16-hole extensional drill program totalling 2558m at the Eos deposit to test the extent of previously identified fresh rock gold mineralisation adjacent to the Eos palaeochannel at Mandilla along with a four-hole infill diamond drilling program at the Theia deposit.

Assays are pending for the Eos drilling while core samples from Theia are expected to be collected and dispatched for assay prior to the Christmas break.

“These in-fill results from the Iris deposit are very encouraging, supporting our plans to include Iris in the upcoming pre-feasibility study for the Mandilla project development, which remains on track for delivery in Q2 2025,” Astral managing director Marc Ducler said.

“The in-fill program was focused on the central section of the Iris deposit, with assay results confirming a very successful infill test, delivering a significant number of drill intersections with gold grades above the MRE grade of 0.8g/t Au.

“The drilling effort at Mandilla and Feysville is now winding down ahead of the Christmas break, with the diamond drill rig recently completing the geotechnical programs at both Eos and Hestia.

“We expect to commence 2025 with a flood of assay results from these recently completed drill programs, with a new round of diamond drilling also scheduled to commence at Kamperman to test a number of targets to improve our understanding of the structural controls to gold mineralisation as well as collecting drill core for metallurgical and geotechnical testing.”

Mandilla sits in the northern Widgiemooltha greenstone belt and is covered by existing mining leases that are not subject to any third-party royalties.

It includes the Theia, Iris, Eos and Hestia deposits that collectively host resources of 37Mt at 1.1g/t for 1.27Moz of contained gold.

To date, metallurgical testing undertaken on these deposits has demonstrated high gravity recoverable gold, fast leach kinetics and exceptional overall gold recoveries with low reagent consumptions and coarse grinding, all of which translate to relatively affordable capital expenditure and low operating costs.

This is aptly demonstrated by the company’s September 2023 scoping study based on a standalone project comprising three open pit mines over the Theia, Eos and Hestia deposits that feed into a 2.5Mtpa processing facility to produce between 80,000oz and 100,000oz of gold per year.

Capex was estimated at ~$191m with all-in-sustaining costs running at ~$1648/oz.

Using a now very conservative Australian gold price of $2750/oz, this would generate free cashflow of $740m over the life of mine and deliver net present value and internal rate of return – both measures of profitability – of $442m and 73% respectively.

Payback was forecast at just 0.75 years.

These are several reasons why a PFS might improve on the already sterling findings of the scoping study.

First up is that gold prices have run way ahead since the initial study was released and are currently sitting well above $4100/oz.

The study also does not include any contribution from the Iris deposit or the company’s nearby Feysville project, which currently hosts a 196,000oz resource estimate.

Deposits at Mandilla are now due for a resource update while recent drilling at the Kamperman deposit returned encouraging results such as 33m at 3.75g/t gold from 58m that bodes well for a resource upgrade.

AAR plans to start off 2025 with a diamond drilling program at Kamperman to improve the structural understanding of the controls to gold mineralisation and to collect drill core for metallurgical and geotechnical testing.