Maiden metallurgical testing at Astral Resources NL’s Kamperman and Rogan Josh gold deposits within the Feysville Project has delivered highly encouraging results, with gold recoveries exceeding 98% at Kamperman using the same low-cost processing route proposed for the nearby Mandilla Project.
Map illustrating location of Mandilla, Spargoville and Feysville Gold Projects.
A total of 172 crushed samples were composited to form five representative bulk samples from Kamperman and two from Rogan Josh, enabling preliminary evaluation of gold recoveries under standardised conditions. At Kamperman, three of the five samples returned an average gold recovery of 98.1%, confirming excellent metallurgical response at a coarse grind size of 150 micrometres, with 200 parts per million (ppm) free cyanide and a pH of 8.9.
The remaining two Kamperman tests, which averaged 87.9% gold recovery, were affected by elevated copper levels in the samples, which depleted available free cyanide. These tests will be re-run with increased cyanide concentrations, with expectations that recoveries will improve beyond 90%.
Map of the Kamperman Deposit illustrating locations from which samples for metallurgical testing were taken.
At Rogan Josh, testing returned an average gold recovery of 91.5% despite a relatively low average head grade of 0.70 grams per tonne (g/t) gold, also demonstrating solid performance.
Reagent consumption across the program averaged 0.41 kilograms per tonne (kg/t) of cyanide and 1.40 kg/t of lime, with copper-bearing Kamperman samples requiring higher cyanide inputs of 1.1 kg/t.
Map of the Rogan Josh Deposit illustrating locations from which samples for metallurgical testing were taken.
These results follow the announcement of maiden Mineral Resource Estimates in November 2024, comprising 2 million tonnes (Mt) at 1.3 g/t gold for 83,800 ounces at Kamperman and 0.7 Mt at 1.3 g/t for 27,400 ounces at Rogan Josh. No metallurgical testing had been completed at the time of that estimate.
The positive outcomes now support the inclusion of the Feysville deposits in the Mandilla Pre-Feasibility Study, which remains on track for completion this quarter.
“These metallurgical test results from the Kamperman and Rogan Josh deposits clearly demonstrate that the simple, low-cost processing pathway being pursued in the Mandilla PFS will also be suitable for processing Feysville ore,” Astral Resources’ managing director Marc Ducler said.
“Our intention with the Mandilla PFS is to incorporate the Feysville deposits as valuable sources of higher-grade satellite ore feed into the proposed 2.5 million tonnes per annum Mandilla process plant. These latest test results pave the way for the inclusion of the Kamperman, Think Big and Rogan Josh deposits into the PFS mine plan.”
“Five metallurgical tests were completed at Kamperman. The results can be classified as free-milling, with three of the five tests returning an exceptional average overall gold recovery of 98.1%. The remaining two bulk samples contained copper mineralisation, which consumed the available free cyanide during the test and, therefore, slowed the dissolution of gold. These tests returned an average overall gold recovery of 87.9%. These tests will be repeated with higher initial free cyanide concentrations, with the expectation that the overall gold recovery for these samples will increase significantly as a result.”
Feysville and Mandilla drilling advances with assays due this quarter
The company isn’t taking a breath. Assay results from Astral’s recently completed air-core and reverse circulation (RC) drilling campaigns at Feysville are expected in the coming weeks, with the air-core assays due later this month and RC results anticipated before the end of the June quarter.
The air-core campaign comprised 313 holes for 8,364 metres, while the RC program totalled 46 holes for 5,890 metres, both designed to enhance geological understanding and support future resource updates.
Following the completion of the Feysville RC program, the drill rig was mobilised to the Iris deposit at the Mandilla Gold Project. It is currently completing an in-fill program of 17 RC holes for 2,683 metres, aiming to upgrade the existing Mineral Resource of 4.3 million tonnes at 0.8 grams per tonne gold for 108,000 ounces of contained gold.
Next, RC drilling will start on the newly acquired Spargoville tenure, focusing on extensions south of the Hestia deposit, which currently holds a Mineral Resource of 2.4 million tonnes at 1.2 grams per tonne gold for 91,000 ounces of contained gold. The program will test for strike extensions of the shear-hosted mineralisation, guided by regional magnetic data suggesting continuity of the shear zone.
Following this, a broader 5,000-metre exploration program will be launched across Spargoville. This initiative will assess the wider potential of the 8-kilometre Spargoville Shear Zone, targeting both extensions of known mineralisation and untested gold targets within the region.