BHP is working with leading Australian and international experts to investigate methods to enhance mineral carbonation rates to store more CO2 into tailings through different processes and engineering solutions.
An example can be found at BHP’s Mount Keith nickel mine in WA’s Goldfields, home to one of Australia’s biggest tailings dams which also serves as a massive carbon sink.
The 5km-wide dam helps lower the operation’s carbon footprint through the natural weathering process of mineral carbonation, where carbon dioxide reacts with mineral rocks such as serpentine to form harmless solid carbonates.
This allows for the safe and permanent storage of about 40,000t of carbon dioxide each year, the equivalent of taking 15,000 cars off the road.
BHP Nickel West’s Samantha Langley said minerals in ore could absorb CO2 in the same way trees can.
“Although mineral carbonation is a process that can take thousands of years in nature, we don’t have thousands of years to address the impacts of climate change,” Ms Langley said.
“It’s an exciting opportunity to see if we can use technology and different tailings management practices to speed up the process, and store away carbon dioxide much faster.”
Mineral Carbon International (MCI) CEO Marcus Dawe said mineral carbonation was not just a way of reducing carbon emissions but also provided profitable decarbonisation pathways for the mining, manufacturing, hydrogen and other power generation sectors.
MCI’s “global reference pilot plant” in Newcastle, NSW, uses carbon engineering processes to transform captured CO2 emissions from industrial sources into solid materials that can be used to manufacture valuable products such as building materials.
The plant has demonstrated how mineral carbonation can be integrated at scale in mineral processing, steel, cement, hydrogen, gas and chemical production.
“It is the only place in the world where you can validate the economics of a large-scale plant as we progress the technology towards commercialisation,” Mr Dawe said.
“We are raising significant capital and doing pre-feasibility studies for multiple mining companies and talking to the biggest companies first to basically pave the way for multiple MCI plants to be built adjacent to industrial facilities right around Australia.
“MCI has shown how to decarbonise much of the mining and manufacturing sectors without the need for an immediate price on carbon.
“Mineral carbonation is very aligned to the production of hydrogen—almost every hydrogen project has MCI in its consideration.”
Mr Dawe also described the technology as a “gateway technology to sustainable metals” that would also enable recycling and remediation of hazardous contaminants in the mining industry.
The Federal Government recently announced five priority technologies — hydrogen, carbon capture and storage, soil carbon, low carbon steel and aluminium production and long duration energy storage — will get funding under the Technology Investment Roadmap that would plough $18b into low emission technologies over the next decade.
Mr Dawe said the announcement was a step in the right direction as it would enable projects that could harness mineral carbonation to produce valuable products.