Arizona Sonoran Copper Company says positive tests with Rio Tinto’s Nuton copper recovery technologies could open a door to project scaling options at its Arizona properties.
The junior has the former Asarco-run Sacaton mine, now called Cactus, and contiguous ground at Parks/Salyer, in the US state.
It provided sample material from primary and enriched sulphide zones at both properties, as well as a tailings storage facility at Cactus, in December last year. Thirteen leach test columns are said to be 75-to-150 days through a 300-day, phase-one leach cycle.
“Positive” preliminary column leach metallurgical extraction rates of 61-82% in five columns containing primary sulphide samples have been reported. Nuton is said to be reassessing additives for a column with biotite achieving lower extraction rates.
Arizona Sonoran Copper Company (ASCU) said it sent the samples to the Nuton testing lab after initial mineralogical analysis and associated performance modelling of ASCU material.
“The columns are leaching under a range of conditions and additive combinations with a view towards identifying the ideal Nuton offering for further test work and commercial deployment,” ASCU said.
“With ASCU input, the metallurgical programs are overseen by the Nuton technical team and have been provided qualified person confirmation by Samuel Engineering.”
George Ogilvie, ASCU CEO, said the company was encouraged that initial column testing was consistent with the early Nuton modelling.
“While our onsite teams remain focused on delivering a robust prefeasibility study based on our oxides and enriched material, Rio Tinto’s Nuton technologies present ASCU with future optionality for continued scaling of our assets from our currently excluded primary resource,” he said.
“We look forward to continuing to explore the leaching opportunity with Nuton, which would utilise a traditional SX/EW plant for the primary sulphides, and has a cleaner footprint than a concentrator, lower GHG emissions and reduced water consumption requirements.”
The Nuton flowsheet is a conventional crushed and agglomerated feed, bio-heap leach flow sheet, for heap leaching of copper sulphide minerals, but it adds catalytic and other reagents, as well as a bacterial growth and inoculation facility.
“Nuton has a wide range of potential use cases,” the firm’s CEO Adam Burley said.
“At Cactus and Parks/Salyer we are encouraged by the potential of Nuton to unlock copper resources currently not in the company’s mine plan. This would increase resource utilisation and enable a larger, more economically and environmentally efficient operation.”
ASCU and Nuton have a material testing agreement in place and are said to be exploring potential commercial frameworks.
