Metallurgical testwork completed for Central Queensland’s Briggs copper project has delivered encouraging results for Canterbury Resources.

Managing director Grant Craighead said the work confirmed the favourable metallurgical characteristics of the Briggs deposit, delivering high metal recoveries into high-quality saleable concentrates.

“Significantly, this is being achieved at coarse primary grind sizes which should minimise power consumption and enhance the economics of a conceptual large-scale, long-life copper mining and processing operation,” Mr Craighead said.

“Looking ahead, an updated mineral resource estimate will be released in March, followed by results from the Briggs scoping study in mid-2025.”

Related: Latest Briggs assays confirm southern porphyry discovery

Completed by Auralia Metallurgy under the supervision of Scott Dalley Franks, preliminary froth flotation testwork achieved:

• Recovery: 89-90 per cent of the copper into final (cleaner) concentrates.
• Concentrate grade: greater than 25 per cent copper.
• Primary grind size: 150µm to 212µm, with no material impact on recovery at the coarser grind size.

Molybdenum is also recovered into the copper concentrate, achieving up to 75 per cent recovery and a concentrate grade of up to 3,200ppm molybdenum.

The metallurgical testwork program has progressed to locked cycle flotation testing for master composites.

Results are expected later this quarter and will be used to update the preliminary process flowsheet and recovery-grade curves.

Cantrebury Resources said additional testwork to assess copper recoveries at even coarser primary grind sizes (300µm) would commence shortly and may lead to further reductions in estimated power consumption for mineral processing and for input into the scoping study.

Briggs has an established inferred mineral resource estimate of 415Mt at 0.25 per cent copper and 31ppm molybdenum based on its Central and Northern porphyry deposits.

You may also like: