Cyprium Metals Commences Acid Leaching at Nifty After 17-Year Pause
Key Takeaways
- Acid solution has been applied to the Nifty heap leach pads for the first time in nearly 20 years, marking the formal start of leaching activity at the complex.
- A 14-well direct injection trial confirmed commercial flow rates of ~250m³/hr and the wellfield has since expanded to 98 production wells, unlocking ~1.7 million tonnes of accessible material — above the 1.2 million tonnes targeted in the Nifty PFS.
- The SX plant is substantially mechanically complete and the EW plant is in final preparation, with first copper cathode expected during Q4 CY2026 wet commissioning and ramp-up.
- All regulatory approvals are in place and the project has recorded zero lost time injuries from the start of construction.
- Cyprium has outlined a multi-stage growth roadmap targeting expansion from ~6,000 tpa to ~20,000 tpa cathode capacity, with open pit oxide inclusion and updated Mineral Resources and Ore Reserves estimates expected in H2 CY2026.
Nifty copper complex stirs to life as Cyprium applies acid to heaps for first time since 2009
Acid commissioning has commenced on the existing heap leach pads at the Nifty Copper Complex in Western Australia, marking the first time leaching solution has been applied to these heaps since operations ceased in 2009. Cyprium Metals (ASX: CYM), a copper developer focused on the phased restart of Nifty in the Paterson region, announced that the solvent extraction (SX) plant is now substantially mechanically complete and first cathode is expected in Q4 CY2026 during wet commissioning and ramp-up. The team has maintained a strong safety record with zero lost time injuries (LTIs) from the start of construction.
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Q3 CY2026 commissioning milestones at a glance
The quarter delivered a series of concrete commissioning achievements across the heap leach, pond, and plant workstreams:
- Acid commissioning commenced on existing heaps — the first leaching activity on these pads in close to 20 years
- Direct injection leaching trial validated well design and confirmed commercial flow rates of ~250m³/hr and beyond across a 14-well trial
- Wellfield expanded from 14 trial wells to 98 production wells, with ~1.7 million tonnes of material now accessible via wellbore
- SX plant substantially mechanically complete; dry commissioning and commissioning with water under way
- EW plant substantially mechanically complete; preparing for cathode and anode installation
- Rectiformer and transformer installed; firewater infrastructure substantially complete
- All regulatory approvals in place, pending successful completion of commissioning
- Zero lost time injuries recorded from start of construction
Executive Chairman Matt Fifield
“Applying acid solution to the existing heaps is a significant milestone for Cyprium – this is the first leach on these pads in nearly twenty years.”
“Phase 1 cathode production restart is the first step in building Australia’s next great copper company.”
What is SX-EW copper production and why does it matter?
SX-EW stands for solvent extraction and electrowinning, a two-stage hydrometallurgical process used to produce pure copper cathode from low-grade oxide material without the need for smelting. In the first stage (SX), copper-bearing solution drawn from the heap leach pads is chemically processed to strip and concentrate the dissolved copper. In the second stage (EW), that concentrated solution is passed through electrolytic cells where copper is electroplated onto stainless steel cathode sheets.
The workflow at Nifty runs: heap leach pads feed copper-rich solution into collection ponds, which is pumped to the SX plant for concentration, then passed to the EW plant where pure copper cathode sheets are harvested.
Direct injection leaching is notable because it differs from traditional surface application of leach solution. Instead, wells drilled into the heap inject solution under pressure directly into the ore material, enabling faster contact, higher flow rates, and access to a greater volume of material than surface methods allow.
For investors, this is a brownfield restart with existing approved infrastructure, lower capital requirements than a greenfield build, and a near-term pathway to copper cathode revenue.
Heap leach, injection wells, and plant: where each workstream stands
Heap leaching and direct injection trial results
Acid solution is now being introduced to the heaps via the eastern intermediate liquor solution (ILS) pond. Sulphuric acid is being added to existing solution in the eastern ILS pond to create an acidified ILS, which is then transported to the heaps.
The 14-well water flush trial tested the hydrostatic properties of the heaps, confirmed well design, and demonstrated the ability of the existing heaps to accept injected solution at commercial flow rates of ~250m³/hr and beyond. The introduction of water alone produced copper outflows in sufficient grade and quantity to commission the SX-EW plant.
Following the successful trial, Cyprium expanded the wellfield from 14 wells to 98 production wells. The established wellfield is expected to access ~1.7 million tonnes of material, above the previously targeted level of 1.2 million tonnes of leachable inventory relative to rates assumed in the Nifty Pre-Feasibility Study (PFS).
SX plant — substantially mechanically complete
Key milestones completed across the SX plant include:
- Piping installation complete on all primary settling tanks (E1, E2, S1), and on crud, clay, strong electrolyte, coalesced and loaded organic tank lines, and raffinate tanks
- Fibreglass repairs complete on all tanks, including settling, primary and secondary mixing tanks
- Pumps installed at loaded organic tank, loaded organic coalescer tank, strong electrolyte tank, and raffinate tank
- Fire system and ring main substantially complete
- Hazardous area (static electricity) audit completed
- Dry commissioning and commissioning with water under way
EW plant and electrical — final stretch
The EW plant is substantially mechanically complete with all major equipment delivered and installed. Remaining scope covers completion of cell top furniture installation, stripping machine refurbishment, loading of cathodes and anodes, and finalisation of electrical and instrumentation work.
On the electrical side, rectiformer and transformer lifts are complete, HV cable runs connecting the rectiformer to the power station are complete, and the HV approval process is complete. Failure of existing high voltage components during testing required procurement and expediting of replacement parts; the schedule has been maintained by progressing pre-commissioning activities using auxiliary power. MCC buckets are largely complete, with final PLC/SCADA and instrumentation installation remaining.
| Area | Status | Key Remaining Scope | Next Milestone |
|---|---|---|---|
| Heap Leach Pads | Acid commissioning commenced | Ramp up leaching rates | Build grade to support production |
| Solvent Extraction (SX) | Substantially mechanically complete | Dry/water commissioning progressing | Wet commissioning with process solution |
| Electrowinning (EW) | Substantially mechanically complete | Cathode/anode install, instrumentation | First cathode in Q4 CY2026 |
| Electrical & Instrumentation | HV approval complete | PLC/SCADA, earthing/bonding | Safe energisation |
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Beyond Phase 1 — a pathway to targeted 20,000 tpa cathode capacity
Cyprium has outlined a multi-stage growth roadmap extending well beyond the current Phase 1 restart. The company is completing planning work and capital estimates to expand the SX-EW plant from the targeted ~6,000 tpa cathode production capacity of the Phase 1 project to a targeted ~20,000 tpa. These figures represent targeted production capacities of the SX-EW plant and are not production targets.
The successful direct injection leaching trial is expected to be a key enabler for expansion. Accessing heap material via wellbore is expected to be quicker and less costly than the surface leach method, and the wellfield already in place is expected to reach ~1.7 million tonnes of material, above the 1.2 million tonnes of leachable inventory previously targeted relative to Nifty PFS assumptions.
Separate from the heap leach pads, copper mineralisation at Nifty waste dump has also been identified, adding another potential source of leachable material to the broader inventory picture as Cyprium progresses its multi-stage expansion plans.
The growth sequence Cyprium has outlined runs as follows:
- Phase 1 cathode production restart
- SX-EW plant capacity expansion
- Open pit oxide inclusion and updated Mineral Resources and Ore Reserves estimates (expected in the second half of CY2026)
- Open pit sulphides and concentrator refurbishment
On exploration, final assay results from the Rainbow drilling programme remain outstanding. Initial results showed conflicting information during normal QAQC processes, and samples have been sent to a second laboratory for reprocessing. The company expects the data back early next quarter.
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