Fortescue has completed the commercial sale of more than 40 tonnes of copper concentrate that underwent arsenic removal using its Toowong Process technology at a demonstration plant in Brisbane, Australia.
The sale marks a significant development for the company as it seeks to offer an alternative method for addressing elevated arsenic levels in copper deposits around the world.
The commercial sale is a notable step because it moves the Toowong Process beyond testing and into the marketplace, showing that treated material can find a buyer.
The concentrate sold contained less than 0.25 per cent arsenic, having been processed from feedstocks with concentrations as high as 7 per cent.
The Toowong Process is a hydrometallurgical method that operates at low temperature and pressure and is designed to separate arsenic from copper concentrates.
Fortescue acquired the underlying technology in 2022 and has spent the past four years on development and testing, logging more than 3,000 hours across seven campaigns.
The company’s results rest on extensive operating data.
Seven campaigns and thousands of hours of operation at the Brisbane plant have given Fortescue a base of evidence on how the process performs with feedstocks of varying arsenic content.
Results from the demonstration site indicate the process can reduce arsenic levels in concentrates to below 0.3 per cent while retaining more than 99.9 per cent of the original copper content.
This result is significant for the economics of any treatment route, because copper lost during processing directly reduces the value recovered from each tonne of ore.
Conventional arsenic removal from copper ores commonly relies on roasting, a highly energy-intensive process that generates significant emissions and requires complex controls for toxic by-products.
Fortescue states that the Toowong Process offers comparable capital and operating costs while reducing energy consumption and emissions, with arsenic captured in a stable, solid form.
Capturing arsenic in a stable, solid form also addresses the handling concerns that come with toxic by-products, an issue that has weighed on conventional approaches.
For miners, arsenic has long been a barrier to bringing some deposits to market, since concentrates carrying high levels of the element can be difficult to sell.
A cost-competitive treatment option that avoids roasting could therefore widen the range of ore bodies considered commercially viable.
Arsenic contamination has historically limited the marketability of some copper concentrates, with smelters often unwilling to accept material with high impurity levels or imposing penalties on it.
Fortescue growth and energy CEO Gus Pichot linked the development to the company’s history in iron ore, saying: “In the early days of iron ore, Fortescue challenged the assumption that lower-grade deposits could not be developed competitively.”
He added: “The Toowong Process brings that same mindset to copper.”
Industry forecasts suggest demand for copper could rise by more than 50 per cent by 2050, driving the need to exploit more complex ore bodies that frequently contain higher levels of arsenic.
Technologies that unlock harder-to-process resources are likely to draw growing industry attention as demand rises.
The technology is also being evaluated on concentrate from Fortescue’s Cañariaco Copper Project in Peru. Fortescue is undertaking further optimisation and engineering work to reduce the costs associated with the process.
Last month, Fortescue produced the first hot metal at its Christmas Creek Green Metal Project in Western Australia.
