- St George Mining (SGQ) has confirmed excellent metallurgical recoveries and concentrate grades for samples from its Investigators prospect
- Investigators is part of the Mt Alexander nickel-copper-cobalt-platinum group element (PGE) project in Western Australia’s north-eastern Goldfields
- Samples of massive and disseminated sulphide mineralisation from Investigators were tested to assess if nickel and copper could be recovered by a flotation process and to determine the PGE content in the concentrates
- Saleable grades of both nickel and copper concentrates were produced, with elevated levels of PGEs reported at up to 18.1 grams per tonne
- Meanwhile, testwork is ongoing for samples at the Stricklands deposit, with aims to complete a scoping study for open-pit operations by the end of the year
- St George Mining is trading ten per cent higher at 11 cents
St George Mining (SGQ) has confirmed excellent metallurgical recoveries and concentrate grades for samples from its Investigators prospect.
Investigators is part of the Mt Alexander nickel-copper-cobalt-platinum group element (PGE) project in Western Australia’s north-eastern Goldfields.
High-grade recoveries
Samples of massive and disseminated sulphide mineralisation from Investigators were tested to assess if nickel and copper could be recovered by a flotation process and to determine the PGE content in the concentrates.
St George reports the results are favourable and likely to have a positive impact on the project’s economics, with test work demonstrating the ability to produce nickel and copper concentrates at saleable grades from both massive and disseminated sulphide mineralisation.
Massive sulphide samples yielded concentrates grading up to 16.2 per cent nickel and 30.3 per cent copper. Both elements had recoveries of 90.6 per cent.
Disseminated sulphides yielded lower grades — 13.6 per cent nickel and 25.1 per cent copper at around 60 per cent recovery — but higher levels of PGEs.
The PGE recoveries from the Investigators samples are significant to the project’s overall economics. Elevated levels of palladium and rhodium in particular, which are trading at historically high prices, will attract valuable smelter credits.
PGEs were recovered at 18.1 grams per tonne (g/t) in the disseminated copper concentrate, and 8.1g/t from the disseminated nickel concentrate.
St George Executive Chairman John Prineas says the results bode well for the project’s viability.
“The high quality of our Mt Alexander mineralisation has been confirmed with separate clean nickel and copper concentrates produced from both the massive and disseminated sulphides,” John said.
“Importantly, we are seeing high values of PGEs, cobalt and silver — all of which could generate significant credits and have a positive impact on the economics for a potential mining operation at Mt Alexander which is currently being assessed by ongoing studies,” he added.
“We are confident that the metallurgical results can be further optimised as we undertake more detailed test work and progress marketing studies to maximise potential net smelter revenues,” John concluded.
Next steps
The potential blending of the nickel and copper concentrates has not yet been assessed but is likely to provide an opportunity to optimise the overall nickel concentrate produced. This will be further investigated in more detailed
metallurgical testwork.
St George will also assess bulk flotation techniques, as the ore samples appear to lend themselves equally to bulk flotation as to split floatation of nickel and copper.
The individual metal grades for bulk flotation are yet to be assessed, but if similar recoveries are possible, this will provide alternative strategies for the processing and marketing of ore recovered from Mt Alexander.
Metallurgical testwork is also underway with XPS in Canada on the mineralisation from the Stricklands deposit, with aims to complete a scoping study for an open-pit mining operation.
The scoping study is expected by the end of the year.
St George Mining is trading ten per cent higher at 11 cents at 12:02 pm AEST.