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Arizona Sonoran Copper (TSX: ASCU) an emerging US-based copper developer and near-term producer, reported on Monday positive preliminary column leach metallurgical extraction rates using Nuton technologies at its Cactus mine.
Last year, Arizona Sonoran entered into a strategic partnership with Rio Tinto (ASX: RIO) focused on the world’s second biggest miner’s Nuton technologies that included a private placement of $27 million. The company’s 100% owned Cactus is a brownfield copper mine located on private land in western Pinal County, Arizona.
Nuton has a portfolio of proprietary copper leach related technologies and capabilities, developed by Rio Tinto to deliver increased copper recovery and environmental performance.
Primary sulphide extraction ranges from 61% to 82% based on five columns, including two early cycle columns returning 83% and 61%, two mid-cycle columns above 70% and one with lower extraction based on biotite content.
Nuton is currently reassessing the additives for this low extraction column to address future biotite exposure, which accounts for approximately 1-2% of the Cactus West deposit in the primary zone.
A total of 13 ongoing columns are approximately 75-150 days through their 300-day leach cycle and include samples from the sulphide, both primary and enriched (secondary sulphide) zones from both Cactus and Parks/Salyer deposits, as well as from the tailing facility.
In December, samples were sent to the Nuton testing lab to begin column leach testing, following 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 right Nuton offering for further test work and commercial deployment.
With ASCU input, the metallurgical programs are overseen by the Nuton technical team and have been provided qualified person confirmation by Samuel Engineering.
“We are extremely encouraged that the initial column testing is consistent with the initial modelling presented by the Nuton team, Arizona Sonoran CEO George Ogilvie said in a news release.
“While our onsite teams remain focused on delivering a robust PFS 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,” Ogilvie said.
“We look forward to continuing to explore the leaching opportunity with Nuton, which would utilize a traditional SX/EW plant for the primary sulfides, and has a cleaner footprint than a concentrator, lower GHG emissions and reduced water consumption requirements.”
