Fortescue's world-first arsenic removal technology unlocks new potential for global copper deposits

Fortescue has sold more than 40 tonnes of copper concentrate cleaned using its new world-first arsenic removal technology, creating a solution for a complex problem facing the global copper industry.   
 
The patented Toowong Process uses a low-temperature, low-pressure hydrometallurgical method to separate arsenic from copper concentrate. 
 
Fortescue acquired the technology in 2022 and has been developing and testing it over the last four years at Fortescue’s Brisbane demonstration plant. Across seven campaigns and more than 3,000 hours, the Toowong Process reduced arsenic levels in concentrates to below 0.3 per cent, while also retaining more than 99.9 per cent of the copper.  
 
Arsenic has been a major barrier to unlocking new copper resources globally and its removal from copper ores has conventionally relied on roasting, an incredibly energy-intensive process. Roasting generates significant emissions, requires complex infrastructure and produces toxic water-soluble arsenic bearing gas and dust emissions that need to be controlled. 
 
The Toowong Process is proving to be an economic alternative, with comparable capital and operating costs, improved output and reduced energy consumption and emissions. 
 
The first 40 tonnes of cleaned copper concentrate produced from Fortescue’s Brisbane site contained less than 0.25 per cent arsenic, reduced from feedstocks containing up to 7 per cent of the contaminant. This product has now been sold, demonstrating that the Toowong Process can produce marketable, commercially competitive copper concentrate from high-arsenic feedstocks. 
 
Fortescue Growth and Energy CEO Gus Pichot said, “Technology and innovation are central to Fortescue’s future growth. We look for problems others see as barriers and work out how to solve them.” 
 
“In the early days of iron ore, Fortescue challenged the assumption that lower-grade deposits could not be developed competitively. The Toowong Process brings that same mindset to copper.” 
 
“This technology has the potential to make high-arsenic deposits more economically viable, addressing major processing challenges and eliminating emissions at the same time.” 
 
 
“The world needs more copper to build renewable energy projects and expand electricity networks and Fortescue’s innovations will be key to unlocking the resources that can meet that demand,” Mr Pichot said.  
 
“This is a technology that Fortescue will consider using itself as we explore copper deposits globally. It could also be hugely important for the industry and our peers more broadly as well.”  
 
Global copper demand is forecast to grow more than 50 per cent by 2050, reaching at least 50 million tonnes a year. Existing clean ore bodies are being depleted to meet that demand, forcing copper producers to explore and develop more complex deposits that can contain higher levels of impurities, including arsenic.  
 
Until now, arsenic has made some copper concentrates unmarketable, with smelters unwilling to accept product or imposing costly penalties that reduce value. High arsenic levels can also constrain mine plans if material must be blended, treated or excluded. 
 
The Toowong Process has the potential to: 

• Improve the saleability of copper concentrate: removing arsenic turns otherwise unmarketable concentrate into a product that can be sold. 
• Increase mining inventory, developments and production: fewer arsenic constraints mean producers can optimise mine inventories, lower development costs and improve production over the life of an asset.
• Reduce environmental impacts: Compared with roasting, the process uses less energy, generates lower emissions and captures arsenic in a stable, solid product. 

 
Fortescue is continuing to optimise the Toowong Process and advance its commercial engineering, with a focus on further reducing capital and operating costs. 
 
This includes testing concentrate produced from Fortescue’s Cañariaco Copper Project in Peru. At Cañariaco, the process has the potential to unlock significant value by making more of the project’s concentrate marketable, helping to support the conversion of more resources into mining inventory and enabling a more flexible, lower-cost mine plan with stronger production over the life of the asset. 

Editors Note: Images can be found here