Aeris Resources achieves breakthrough at Stockman with material leach test improvements

Flotation and Albion leach test work results at Aeris Resources’ (ASX: AIS) Stockman polymetallic deposit in Victoria have demonstrated an ability to materially improve project returns.

Tests were completed on a bulk concentrate prepared from a modified flotation flowsheet containing copper, zinc, gold and silver, with results showing the ‘full leach’ of copper and zinc as the preferred Albion process flowsheet for Stockman.

A ‘zinc-only leach’ that was also tested to provide flowsheet options and help confirm the full leach results under a different test regimen achieved 98% recoveries of copper and zinc, with overall recoveries of more than 90% and improved recovery of gold.

Enhanced economics

Executive chair Andre Labuschagne said the test results would be a catalyst for improving Stockman’s profitability.

“These latest results validate our view that the Albion process has the potential to significantly enhance the overall economics of the Stockman project,” he said.

The company plans to further study, engineer and complete more detailed tests to produce an export-quality copper concentrate and a bulk concentrate containing copper, zinc, gold and silver for further treatment.

“We expect our ongoing tests will create a simpler flowsheet for the processing plant and further enhance the returns through a smaller physical footprint, lower capital and operating costs and reduced energy consumption and carbon emissions,” Mr Labuschagne added.

Stockman acquisition

Aeris assumed ownership of the advanced Stockman project – which contains main deposits at Currawong and Wilga, as well as satellite targets at Bigfoot and Eureka – upon the acquisition of Round Oak Minerals in July 2022.

All tenements are largely under-explored, with multiple surface geochemical and geophysical anomalies yet to be drill tested.

The company released an updated mineral resource estimate in January for Currawong and Wilga totalling 1.48 million tonnes at 2.09% copper, 4% zinc, 0.94 grams per tonne gold and 36g/t silver for 308,000t of copper, 591t of zinc, 445,000 ounces of gold and 17.1Moz of silver.

The estimate was based on 489 surface and underground diamond drill holes from an Acquire database developed by Round Oak and maintained by Aeris.

It comprises in-situ massive sulphide, stringer sulphide and disseminated sulphide mineralisation at both deposits and is reported to remain highly prospective for further volcanogenic massive sulphide discoveries.