Two mining giants have come together to accelerate the development of technology
that could significantly increase water recovery from mine tailings.
This increase would in turn reduce potential safety risks and environmental footprints associated with tailings storage facilities.
“It is in everyone’s interest that we, as an industry, find safer and more sustainable ways to manage tailings,” Rio Tinto chief technical officer Mark Davies said. “As two of the leading companies in the sector, we want to bring our combined knowledge and expertise to address this challenge.”
As a first step, the miners will test the application of an innovative large-volume filter unit at a BHP copper mine in Chile. The filter unit will remove up to 80 per cent of the water in the tailing stream before it is deposited in a storage facility.
Removing more water from tailings would reduce potential risks associated with moisture in storage facilities, reduce the footprint required by such facilities, and create opportunities to productively re-use tailings as raw material for glass, construction or agriculture industries.
“It is important that we keep working together across the global mining sector to raise standards and make sure our operations are as safe and sustainable as they can be,” BHP chief technical officer Laura Tyler said.
“Responsible management of tailings and improved water use is a big part of that.”
Tailings usually takes the form of a liquid slurry made of fine metal or mineral particles and water – created when mined ore is crushed and finely ground in a milling process to enable the metals and minerals of interest to be extracted.
Rio Tinto has been implementing smaller-scale tailings filters since 2005, and this experience will be imperative in the successful application of the new technology.
BHP and Rio will work in collaboration with leading technology and equipment providers, technical experts, research groups and the academic sector.
The new filter unit is currently being manufactured, with construction due to begin in early 2023 and operations scheduled to commence in early 2024. The pilot will test the potential of a large-scale tailings filter unit for scalability and cost-effectiveness across global mining operations.
Any additional water recovered from tailings by filtration can be re-used in processing facilities to reduce overall water consumption.