Chalice’s Gonneville Pilot Opens a New Route to Financing
Chalice Mining has begun a continuous pilot of the full Gonneville processing flowsheet, using five tonnes of representative sulphide ore in a key test for project financing and feasibility work. A separate redesign has reduced the planned PGM elution circuit from five steps to two, although the expected cost savings are not yet quantified.
- Five-tonne continuous pilot now underway across flotation and leach circuits
- Pilot feed grades 1.7g/t 3E, 0.33% nickel and 0.28% copper
- PGM elution simplified from five steps to two
- Nickel-based stripping solution replaces the zinc-based design assumed in the PFS
- Initial flotation results expected in early 2027, with full leach results due in Q2 2027
Add us as a preferred source on Google
Five-Tonne Pilot Tests Gonneville’s Full Flowsheet
Chalice Mining Limited (ASX:CHN) has started what it describes as the final processing de-risking step for its Gonneville PGM-nickel-copper-cobalt project, putting approximately five tonnes of representative fresh sulphide ore through a continuous laboratory-scale pilot.
The work follows the company’s Gonneville pilot preparation, which was scheduled to begin in November alongside feasibility and offtake discussions. Ore from 10 diamond holes was selected across all 11 identified geo-metallurgical domains and grades 1.46 grams per tonne palladium, 0.19 grams per tonne platinum, 0.08 grams per tonne gold, 0.33% nickel, 0.28% copper and 0.025% cobalt.
Flotation and Leach Tests Replicate Proposed Plant Conditions
The pilot will run in three stages. The flotation phase, which has commenced, will process the sulphide feed over one week. A sulphide flotation-tails leach pilot is due to run for three weeks from late November, followed by a five-week test of an oxide ore and sulphide-tails blend from January.
Chalice is using treated wastewater from the Alkimos Water Resource Recovery Facility, the intended process-water source for the project, to make the test conditions as close as possible to those planned for operations. The company expects the work to confirm recovery, product specifications and operating parameters for incorporation into the Definitive Feasibility Study, with an independent technical engineer appointed by debt adviser Cutfield Freeman & Co supervising the pilot.
Leach Elution Reduced From Five Steps to Two
Testwork has also produced a material change to the precious-metals leach circuit. Chalice says the elution process has been reduced from five steps to two, while a nickel-based stripping solution generated from soluble nickel in the ore will replace the high-cost zinc-based solution assumed in the December 2025 Pre-Feasibility Study.
The redesign is expected to deliver modest capital and operating-cost reductions and, more importantly for the company, simplify the leach process. Engineering work is still quantifying the savings, so the announcement does not yet establish how they would affect Gonneville’s overall economics.
Offtake Samples and Financing Milestones
The pilot will produce copper-PGM-gold concentrate, nickel-cobalt-PGM-gold concentrate and PGM doré. Chalice says several international smelters and metals traders have expressed strong interest, with additional interest from Indonesian hydrometallurgical nickel processors, but all products remain uncommitted and no offtake agreement has been announced.
Gonneville is modelled to produce about 45,000 tonnes of copper concentrate and 95,000 tonnes of nickel concentrate a year over more than 23 years of open-pit operation, with potential to expand beyond the current mine plan. Initial flotation results are expected in early 2027, full leach results in Q2 2027, and the Definitive Feasibility Study remains targeted for completion in the second half of 2027 ahead of a planned final investment decision in the first half of 2028.
Get ASX:CHN news the moment it breaks
iPhone & iPad
Android
Bottom Line?
The pilot can turn a modelled processing case into evidence for financiers and offtakers, but the next valuation-critical data points are recoveries, product quality and quantified savings.
Questions in the middle?
- Will the pilot reproduce the recovery and concentrate specifications assumed in the Pre-Feasibility Study?
- How large will the redesigned elution circuit’s capital and operating-cost reductions prove to be?
- Can pilot samples convert stated smelter interest into binding offtake commitments before the final investment decision?
Sources
1-
Gonneville Project advances with pilot plant underway (opens in a new tab)Verified company source. Chalice Mining Limited · 11 Nov 2026 · chalicemining.com
