Preliminary metallurgical test work from an initial sighter study of QMines’ (ASX: QML) Mt Chalmers copper-gold project in Queensland has indicated the project could yield high recoveries from all concentrates and support a relatively simple flotation process.
The test work was designed to establish a preliminary flowsheet and assess the ability to recover the project’s metals into separate flotation concentrates.
It was carried out by ALS Metallurgy at its Perth laboratory with Como Engineers engaged as supervisor.
A composite of stringer mineralisation with a head grade of 1.22% copper, 0.2% lead, 0.02% zinc and 1.05 grams per tonne gold was put through two preliminary open circuit flotation tests.
Sequential flotation produced a copper rougher concentrate.
The lead and zinc grade in this composite were low and QMines said a copper-only circuit flowsheet could be considered for this mineralisation type.
Rougher grades of up to 12.3% copper and 4.6g/t gold were also produced with recoveries of 97.1% copper and less than 0.14% lead-zinc.
Gold predominantly reported to the copper concentrate, grading as high as 4.6g/t.
Massive sulphide mineralisation
A composite of massive sulphide (copper, lead and zinc exhalite) with a head grade of 1.28% copper, 1.42% lead, 3.51% zinc and 4.31g/t gold went through 10 preliminary flotation tests.
Sequential flotation was successful in producing rougher concentrates of copper-lead and zinc.
Rougher grades of up to 15.6% copper, 15.1% lead and 16.6% zinc were produced with “acceptable recoveries” of 88.8% copper, 76.6% lead and 83.6% zinc.
Gold predominantly reported to the copper-lead concentrate, grading as high as 46.9g/t.
Opportunities exist to improve recoveries for both mineralisation types in subsequent testing programs.
QMines executive chairman Andrew Sparke said the metallurgical results were encouraging as lithologically, stringer mineralisation makes up the bulk of the Mt Chalmers resource.
“It is very pleasing to see such excellent results from our initial study as they demonstrate the development potential of this project,” he said.
“We are now planning further work to improve overall recoveries, develop a cleaner flotation and improve flowsheet optimisation.”