Cannindah Resources has reported preliminary NovaCell testwork recovering 94% of copper and 92% of silver at a substantially coarser grind, while rejecting 82% of processed material. The results could support a higher-throughput, lower-energy processing route, although gold recovery and concentrate quality still require further work.
- 94% copper and 92% silver recovery at P80 450 micrometres
- 18% mass pull rejected 82% of processed material
- Conventional flotation produced copper concentrate grading up to 32.5%
- Gold recovery of 68% remains subject to assay uncertainty
- Updated Cannindah Breccia MRE targeted for end-September 2026
Coarse flotation delivers strong copper and silver recoveries
Cannindah Resources Limited (ASX:CAE) has produced an early processing result that could materially change the shape of a future Mt Cannindah plant: NovaCell coarse particle flotation recovered 94% of copper and 92% of silver at a P80 grind size of about 450 micrometres. The test achieved those recoveries with an 18% mass pull, meaning 82% of the processed material was rejected before downstream treatment.
That is a notably coarser grind than the conventional flowsheet, which operates at roughly P80 200-250 micrometres. Cannindah says the potential advantages include higher throughput, lower energy use, a smaller processing footprint and easier tailings management. Those are possibilities rather than established project economics at this stage: the NovaCell work is described as an initial scoping test, and the concentrate still needs downstream refinement to achieve target grades.
Conventional flotation confirms a saleable concentrate route
The conventional testwork provides a second, more established processing option. Using the DSP052 collector in the cleaner stage and a regrind to P80 20 micrometres, iron recovery to concentrate fell from about 21% under the earlier SIBX regime to as low as 4.6%. Copper concentrate grade consequently rose from approximately 15% to as high as 32.5%, while arsenic and uranium were also substantially rejected.
The selected FT-111 conditions produced either a 25.0% copper concentrate at 83.7% copper recovery using two cleaning stages, or an 18.3% concentrate at 89.8% recovery with one cleaning stage. Cannindah says the results confirm that the Cannindah Breccia can produce a saleable copper concentrate with low penalty elements, giving the company a conventional benchmark against which the coarser NovaCell pathway can be assessed.
Gold recovery remains the main qualification
Gold is the less settled part of the result. NovaCell reported 68% gold recovery, compared with 86% in the FT-109 comparison test at a finer P80 250 micrometres. Cannindah cautions that both figures are affected by the spotty distribution of gold, low-grade flotation tails and small cleaner-concentrate masses. Gold results in several tests were estimated rather than directly measured because there was not enough concentrate for a reliable fire assay.
The company plans larger or repeat tests, including work aimed at improving gold recovery and optimising grind size and reagent use. It also recommends gravity concentration ahead of future conventional flotation work to remove coarse gold that may be distorting the interpretation of flotation results.
Results feed into September resource update
The metallurgical program is being conducted by Core Resources using composite samples of more than 150 kilograms from six diamond drill holes. Cannindah intends to use the results in an updated Cannindah Breccia Mineral Resource Estimate, targeted for the end of September. The existing Mt Cannindah resource, released in July 2024, stands at 14.5 million tonnes grading 1.09% copper equivalent, including measured, indicated and inferred material.
The immediate investment question is therefore less about whether the NovaCell test looks encouraging - it does - than how much of that early performance survives broader testing and engineering. The updated resource will provide the next hard data point, while subsequent metallurgical work will need to establish whether the coarse-grind benefits can be converted into credible capital, operating and tailings assumptions without sacrificing gold recovery or concentrate quality.
Bottom Line?
The coarse-grind result strengthens Cannindah's processing case, but the September resource update and larger metallurgical tests must determine whether the potential efficiency gains are commercially durable.
Questions in the middle?
- Will the updated Mineral Resource Estimate materially change the scale or grade profile of the Cannindah Breccia?
- Can further testwork lift gold recovery above the preliminary 68% result while retaining the coarse-grind advantage?
- What concentrate grade, plant configuration and cost assumptions will ultimately emerge from the NovaCell pathway?