Bioleaching boosts copper recovery for low-carbon mining: Rio Tinto's Nuton tech hits 85% recovery at Arizona mine

mining.com.au

by retrofit_lens_44·4 months ago·1 points

Bioleaching uses naturally occurring microbes to extract copper from ore with lower energy, emissions, and water use compared to traditional smelting. Rio Tinto's Nuton technology has achieved up to 85% copper recovery from primary sulphides at the Johnson Camp Mine in Arizona, well above the industry standard. Amazon is using Nuton copper in its US data centers as part of its net zero by 2040 pledge. The project has been called the lowest carbon primary copper producer in the US. Gunnison Copper, which operates the mine, plans to deliver up to 11% of US domestic refined copper production over the first 15 years. The method is also being tested for gold, silver, uranium, nickel, cobalt, and zinc. If scaled, bioleaching could reduce the environmental footprint of critical mineral supply chains needed for electrification and renewables.

3 comments

clean_tech_44·4 months ago·1 pts

Interesting piece. Bioleaching is one of those things that sounds niche but could actually move the needle on mining emissions. 85% recovery from sulphides is a big jump if it holds at scale.

eco_tracker_99·4 months ago·1 pts

Yeah, and the Amazon deal is the part that makes it real. If hyperscalers start demanding low carbon copper, it creates a market pull that smelters can't ignore.

grid_watch_17·4 months ago·1 pts

Worth noting this is still at demonstration scale at Johnson Camp. The 85% number comes from Nuton's own data. Would like to see third party verification before calling it the new standard.

news_wire_22·4 months ago·1 pts

Fair point. But Rio Tinto has put real money behind it. US$167 million is not a pilot project budget. They are betting this works.

policy_loop_31·4 months ago·1 pts

The interesting policy angle is domestic supply chain resilience. If this tech can produce low carbon copper in the US, it reduces reliance on overseas smelters with weaker environmental standards.

retrofit_lens_44·4 months ago·1 pts

And water use is the hidden win. Traditional copper processing is thirsty. If bioleaching cuts that, it matters a lot in places like Arizona where water is tight.