Quebec Hub Proves Mine Waste Can Become a Carbon Vault

Canada's former asbestos mining heartland is now home to the world's first surficial mineralization hub. Launched April 28, 2026, in Thetford Mines, Quebec, the hub is operated by Carbon Removal Canada, Frontier, and the DuGrisAuVert ecosystem. The region's 800 megatonnes of mine tailings hold the potential to permanently remove between 400 and 700 megatonnes of CO2, representing $60 to $175 billion in value (Carbon Removal Canada, 2026).

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What Is Surficial Mineralization?

Surficial mineralization is a carbon removal pathway that uses crushed alkaline rock and mine waste to trap CO2 permanently. When carbon dioxide contacts minerals in materials like serpentinite or other ultramafic tailings, a chemical reaction converts the gas into stable carbonate solids. Those carbonates store carbon safely for thousands of years with no risk of leakage.

Nature does this on its own through weathering, but that takes centuries. Mining accelerates the process by grinding rock into fine particles, dramatically increasing reactive surface area. Research led by University of British Columbia geoscientist Greg Dipple confirmed this happens passively at active mine sites. His team documented tailings at BHP's Mt. Keith nickel mine in Australia offsetting roughly 40,000 tonnes of CO2 per year without any intervention.

Surficial mineralization differs from underground carbon injection. Instead of pumping CO2 into deep geological formations, CO2-bearing air reacts directly with accessible surface-level waste material. That makes it faster to deploy, lower in capital cost, and easier to verify than subsurface approaches.

Why Do Mine Tailings Matter for Carbon Storage?

Mine tailings are the crushed rock waste left after extracting metals like nickel, cobalt, platinum, and diamonds. They are already finely ground, which is exactly what makes them reactive with atmospheric CO2. Most of these piles sit as managed environmental liabilities with no productive use.

The United States alone generates roughly 9 billion tonnes of mine tailings annually (Energy Advances, RSC Publishing, 2025). Globally, alkaline and intermediate mine tailings hold an estimated carbon removal potential of 1 to 5 gigatonnes of CO2 per year (PMC, 2023), comparable to many of the CDR pathways highlighted by the IPCC. Tailings from ultramafic deposits, those that once hosted nickel, platinum, or diamond mines, are the most reactive because they contain high concentrations of magnesium and calcium that bond readily with CO2.

Mineralization also improves the physical properties of tailings. As CO2 reacts with the minerals, the resulting carbonate formation binds rock particles together, improving structural stability and reducing dust. That is a meaningful co-benefit for communities near legacy mine sites.

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How Does the Quebec Hub Work?

The Quebec Surficial Mineralization Hub gives research teams and early-stage companies a fully equipped testing environment with 10,000 tons of serpentinite tailings, shared processing tools, and monitoring equipment already on site. Permitting and community relationships are handled. Teams can run experiments without the years of setup that typically gate this kind of work.

Successful applicants receive prepurchases or research and development grants through Frontier, the advance market commitment founded by Stripe, Alphabet, Shopify, Meta, and McKinsey Sustainability. Frontier has committed to buying more than $1 billion of permanent carbon removal between 2022 and 2030. Its 2025 annual letter put forward a hypothesis that surficial mineralization may be able to deliver hundreds of gigatonnes of CDR at costs below $80 per tonne, driven by the abundance and low processing cost of rock feedstock already handled by the mining industry (Frontier, 2025).

What Makes Thetford Mines the Right Location?

Thetford Mines spent most of the 20th century as the center of Canada's asbestos industry. When that industry ended, it left behind hundreds of millions of tonnes of serpentinite rock waste. Serpentinite is one of the best feedstocks for surficial mineralization. Frontier's own pressure testing identified it as the optimal rock type due to its availability and CO2-absorbing effectiveness.

There is also a remediation co-benefit. Carbon mineralization of asbestos mine tailings converts reactive mineral fiber surfaces into stable carbonate minerals, which can reduce the environmental hazard of exposed asbestos while simultaneously locking away CO2.

How Does This Compare to Other Carbon Removal Approaches?

Surficial mineralization takes a fundamentally different approach from direct air capture and conventional carbon capture and storage. Direct air capture systems pull CO2 from open air using chemical sorbents and currently cost between $600 and $1,000 per tonne, as covered in the growing DAC landscape. Surficial mineralization skips the energy-intensive capture step entirely. It uses CO2-bearing air reacting with reactive rock material that already exists as waste on the surface.

Pathway	Estimated Cost	Storage Type	Scale Potential
Surficial Mineralization	Hypothesis: below $80/tonne at scale (Frontier, 2025)	Solid carbonate mineral, permanent	Hundreds of gigatonnes (hypothesis)
Direct Air Capture	$600 to $1,000/tonne (current)	Geological injection or mineralization	Gigaton-scale by 2050 (projected)
Enhanced Rock Weathering	Falling toward $100/tonne by 2030	Bicarbonate in ocean, permanent	2 to 4 gigatonnes/year by 2050 (Frontier)
BECCS	Varies widely by project	Geological storage	Key IPCC pathway to 2050

Permanence is where mineralization has a clear advantage. Once CO2 converts into stable carbonate rock, it is locked away without ongoing monitoring requirements or leakage risk. That combination of low projected cost and permanent storage is why Frontier and Carbon Removal Canada are investing now in proving the pathway at commercial scale through the Quebec hub.

Who Is Already Working on Industrial Mineralization?

Vancouver-based Arca, a UBC spin-off formerly known as Carbin Minerals, is among the leaders in this space. Arca's technology accelerates carbon mineralization in mine tailings and steel slag. In 2025, the company completed an 18-month pilot at BHP's Mt. Keith nickel mine in Australia, documenting a 10 to 20 times increase in mineralization rate. Arca has since signed an agreement with Microsoft to deliver nearly 300,000 tonnes of carbon removal over 10 years and works with more than 30 mining companies worldwide.

Frontier has also backed Karbonetiq, which cycles alkaline industrial residues through a low-cost passive aeration system, and is actively seeking more teams capable of advancing surficial mineralization at scale.

From Liability to Climate Asset: What Comes Next

The Quebec Surficial Mineralization Hub is now open for applications from companies, startups, and research institutions. Each successful team that demonstrates results contributes proof-of-concept data that speeds up the next project across North America and beyond.

The numbers make the case clearly. Commercial projects at Thetford Mines alone could remove between 400 and 700 megatonnes of CO2 and generate between $60 and $175 billion in economic value, while unlocking recoverable critical minerals from the same tailings (Carbon Removal Canada, 2026). And that is just one site in one province. Globally, the potential across legacy mine sites is far larger, with alkaline tailings estimated to hold 1 to 5 gigatonnes of CO2 removal capacity per year if fully utilized (PMC, 2023).

The mine that once dug up a problem may be the same one that buries it for good.