A sustainable approach to readying critical minerals for decarbonisation
March 07, 2024
Ready, reduce, replace, remove. Driving sustainability in the mining industry.
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In the battle against climate change, mining is often thought of as public enemy number 1. Releasing between 4-7 percent of greenhouse gas (GHG) emissions into the atmosphere every year, it’s clear the industry is a major contributor to global warming. But mining also plays a critical role in the transition to green energy, with minerals extracted through mining used to produce everything from electric cars to solar panels.
So, the industry now finds itself at a critical juncture. We must balance the need for critical minerals against the need to protect the environment. And the cost of investing in green technology must be weighed against consumer attitudes and the social contract the industry depends on.
For us, it’s clear the time is now for a more sustainable approach to mineral processing. Let’s review how we can decarbonise mining activities.
Ready: Mining matters more than ever
More than 80 percent of mines worldwide target minerals critical to renewable energy, according to MIT. For example, an electric vehicle takes six times more minerals than an internal-combustion engine car. Constructing a wind farm requires nine times more minerals than a gas-fired plant. As the shift towards green energy accelerates, we must be ready for the demand for critical minerals.
High Purity Alumina plants aid decarbonisation efforts by producing synthetic sapphire and lithium-ion batteries.
To limit global warming to 1.5°C, the International Energy Agency (IEA) estimates we will need 3 billion tons of minerals and metals to build the technology that generates and stores power from wind, solar, and geothermal. This will quadruple the demand for minerals by 2030. We will need to build new mines, processing facilities, and refineries—164 for lithium, nickel, and cobalt alone—to meet the growing demand. And that’s based on current technologies, not those yet to be invented.
But as mining of minerals ramps up, so too will carbon emissions unless changes are made. For the world’s largest mining companies, decarbonising their activities won’t be a matter of choice. Governments, investors, and the public will demand a different approach. The IEA notes that, even as demand for minerals increases, ‘the social acceptability of mining may decrease if critical mineral mining does not reduce its GHG emissions, which may make it harder to obtain a social licence to operate.’ This means the need to decarbonise mining activities isn’t just about the environment but could be essential to the industry’s survival.
Reduce and replace: The path to net zero
The goal, and challenge, mining companies face is achieving net zero while remaining economically viable.
Scott Odell, a scientist at the MIT Environmental Solutions Initiative who specialises in clean energy and mining, believes there are three ways forward for the industry when it comes to reducing carbon production from mining. The first (and most obvious) is to reduce the consumption of minerals in the first place. But that’s a challenge that goes beyond the mining industry. The second option, according to Odell, is a circular economy. That’s where we recycle minerals instead of mining for new ones. The third is decarbonising mining activities through sustainable mineral processing.
Mining companies are rising to the challenge. They’re adopting new technology to increase efficiency and reduce waste; they’re also increasing their use of renewable energy. Our mining leader Brian Mashford says it best: ‘We’re really at a turning point in the industry now. It’s not about why we’re doing this but about how. We’re seeing a lot of requests to help clients figure out how to implement technologies.’
But as mining of minerals ramps up, so too will carbon emissions unless changes are made.
Stantec has already engineered a high-purity alumina process plant. We’re also helping clients move to battery-electric fleets for open-pit operations and hydrogen-powered vehicles. Other options include small modular nuclear reactors, autonomous modular haulage, and ore sorting.
Mining companies leading the way include Fortescue, which has set ambitious net zero targets. It hopes to achieve net zero by 2040, investing around US$6.2 billion in its iron ore operations. While the initial investment does come at a cost, Fortescue estimates it will create returns in the long run, by eliminating the need for diesel, natural gas, and carbon offset purchases.
Meanwhile, BHP—which is also on the path to net zero—turned on its Northern Goldfields Solar and Battery Storage Facility in 2023. It’s one of the world’s largest off-grid mining solar and battery energy storage systems and features about 70,000 solar panels across 90 hectares of land. BHP worked with TransAlta and Stantec to bring the project to life. The new facility will replace power generated from diesel and gas. It’s a major step towards BHP's aim of decarbonising its mining activities 30 percent by 2030.
But if all mines want to reach these targets, they’ll need to throw out the cautious ‘first to be second’ industry mindset. They must start trialling and adopting new technologies and sustainable approaches to mineral processing.
Remove: From net zero to net negative
Carbon capture and storage (CCS) in mining is the next frontier for mines seeking to reduce carbon production from mining. In fact, research by the Intergovernmental Panel on Climate Change (IPCC) and the IEA shows CCS is the lowest-cost route to meeting global climate targets.
Andy Home, a metals columnist at Reuters, believes CCS holds the potential for mines to not only reach net zero but net negative. He cites Iceland’s Carbfix, a subsidiary of Iceland's Reykjavik Energy, as a leader in this arena.
Building solar farms and battery energy storage not only provides fuel savings but helps to reduce scope 2 electricity greenhouse gas emissions.
Carbfix has captured more than 73,000 tonnes of carbon dioxide from the Hellisheidi geothermal power plant since 2014. The carbon dioxide is pumped underground. There, Iceland’s basalt rock formations convert it into carbonate minerals, ‘effectively trapping the gas in a stable form for millennia’.
Rio Tinto is also developing CCS technology, investing $4 million in Carbon Capture Inc. Carbon Capture uses machines that remove CO2 from the atmosphere. This CO2 can then be permanently stored underground or used to make synthetic fuels, low-carbon concrete, carbon black, or other industrial products that require clean CO2.
Other companies are exploring the potential of swapping out natural gas for hydrogen in their operations to reduce carbon production from mining. Hydrogen doesn’t produce carbon emissions upon combustion. In Australia, where 65 percent of our electricity comes from coal, the Mineral Council has said CCS and hydrogen production will be ‘critically important’ to the future of mining.
‘The idea of a nickel mine or aluminium smelter being net negative in terms of carbon emissions may seem far-fetched,’ says Home, ‘but the reality may be coming sooner than you think’.
Investing in the future of the sector
Decarbonising the mining sector—which has historically been resistant to rapid change—is a formidable challenge. But the current commitments made by some of the industry's biggest players show that it’s not impossible.
The need to slow climate change is ever more urgent. That means the demand for critical minerals is also urgent. So, investing in sustainable mineral processing is more than just an investment in the environment. We believe it will prove an investment in the resilience and long-term viability of the sector itself.