Metwork results are in
Galileo Mining (ASX:GAL) today announced very positive test work results from its Callisto palladium-nickel-copper-platinum-gold-rhodium discovery in WA.
Initial metallurgical test work results on a diamond core composite sample of disseminated sulphide mineralisation has demonstrated very high recoveries for key metals. It has also shown the disseminated sulphide mineralisation responds very well to sulphide flotation at industry standard conditions.
This testwork forms the basis for more advanced testing to understand how best to extract the metals from the Callisto mineralisation.
Sulphide flotation (at an industry standard 75µm grind size) achieved what GAL described as “excellent results” with:
- 94% copper recovery,
- 82% palladium recovery,
- 77% nickel recovery,
- 79% gold recovery,
- 78% platinum recovery, and
- 63% rhodium recovery.
As GAL has a very consistent style of disseminated sulphides at Callisto, it expects that the metal recoveries will be similar from other sections of the mineralisation.
These positive metwork results mark completion of a milestone we set in our GAL Investment Memo towards collecting data to support mine development studies.
We had also set the following expectations in our last GAL note:
- Bull case = Recovery rates of 80%+
- Base case = Recovery rates of 70-80%
- Bear case = Recovery rates of <70%
Already, the initial results suggest that the mineralisation here may be amenable to the production of a single bulk concentrate, similar to that produced from operating South African PGE mines, which currently produce the bulk of global PGE.
Today’s results compare well to Ivanhoe Mines’ Platreef deposit in South Africa, which range from high-70% to low 90% recoveries. And we note that it took almost 17 years of optimising the flowsheet at Platreef to bring the results up to that level.
South African palladium-platinum mines commonly produce a single bulk concentrate that maximises PGE recovery. This is a potential option that GAL will look at in its upcoming work at Callisto.
GAL has also previously highlighted the Platreef's similarities to the Callisto discovery and what could be an entirely new palladium-nickel province in WA.
Importantly, the experience in South Africa of GAL’s Technical Director and metallurgist, Noel O’Brien, provides for an extensive network of contacts within the palladium-platinum industry, meaning GAL can draw from a wealth of expertise that is not readily available in Australia.
GAL engaged ALS Metallurgy Pty Ltd to undertake the preliminary metallurgical testing and mineralogical studies on diamond drill samples (from drillhole NRCD337). It obtained a single bulk composite by sampling a nine-metre interval from 154 to 163 metres within the disseminated sulphide mineralised zone.
Now, in order to assess whether a single bulk concentrate can be produced from the Callisto mineralisation, a sequence of further work is being undertaken including cleaner flotation and magnetic test work.
Diamond drill core from met hole NRCD337 at 158m down hole showing bands of disseminated sulphides:
What’s next?
With ~$20 million in cash (as at 31 December 2022), GAL is fully funded to continue the resource drill out program at Callisto and now has both a diamond rig and RC rig on site.
GAL is aiming to define the mineralisation at the discovery for resource estimation and to use the data generated to effectively explore this newly discovered palladium-nickel province.
The following plan map of drilling at Callisto identifies the priority drill target zones and the location of metallurgical drill hole NRCD337 (circled in yellow).
The red dashed lines show the interpreted mineralised zone at 0.5g/t 3E cut-off projected to surface. The source of the mineralisation at Callisto is currently being targeted within the diamond drill zone to the east, as shown.
