Alliance Nickel Advances NiWest Vat Leach Testing After Encouraging Results

Phase 1 Clears the Way for Broader Testing

Alliance Nickel Limited (ASX:AXN) has moved NiWest into a second round of vat leach testing after preliminary work produced what the company described as encouraging nickel and cobalt extraction outcomes. The result is not yet a commercial recovery figure, but it was sufficient for the board to approve the next stage.

The first phase used roughly two tonnes of NiWest ore and examined ore sizing, agglomeration, leach kinetics and extraction performance. Alliance has not disclosed quantified recoveries, acid consumption or operating costs, leaving the central economic case still to be tested rather than established.

Water Infrastructure Is the Economic Prize

Vat leaching is being assessed as an alternative to the on/off heap leach configuration in NiWest’s November 2024 Definitive Feasibility Study. The potential benefit is tied mainly to water: about A$310 million of the DFS capital cost was attributed to infrastructure for the heap leach design, including more than 200 kilometres of water pipeline.

Alliance’s preliminary analysis indicates that a vat leach flowsheet could potentially draw sufficient water locally from the Mt Kilkenny tenement, reducing the need for that infrastructure. That remains a possibility, not a booked saving or an updated project estimate. The company also says the method could improve solution distribution and leach kinetics while retaining an atmospheric leach basis.

Phase 2 Tests Ore Variability and Acid Use

The second phase is intended to more closely replicate anticipated commercial vat conditions, with particular attention to acid usage and ore variability across the Mt Kilkenny deposit. A new suite of composite samples representing the expected life-of-mine ore profile has been sent to the overseas testing facility, where work has commenced.

That broader sampling matters because a flowsheet that performs well on a limited bulk sample would still need to demonstrate consistent behaviour across the orebody. Subject to positive confirmatory results, Alliance says the program could support larger-scale pilot plant testing and help refine the previous feasibility work.

Q4 Testwork Sets the Next Catalyst

Alliance expects Phase 2 to finish by the end of Q4 2026. It plans to publish a fuller summary after the testwork and data validation, including leach performance across the Mt Kilkenny ore profile. Any subsequent feasibility update would focus on whether the lower-water process can reduce NiWest’s capital intensity.

For now, the announcement marks progress in a cost-optimisation program rather than a change to the existing development case. The 2024 DFS assumptions remain in place, and the company cautions that early results should not be treated as evidence of commercial recoveries, operating costs or confirmed capital savings.