Vancouver-based Arca is betting that the mining industry’s path to long-term sustainability—and profitability—runs through its tailings storage facilities. Building on two decades of geochemical research at the University of British Columbia, the company is commercializing technologies that accelerate carbon mineralisation, a process in which carbon dioxide (CO₂) reacts with ultramafic rock waste to form permanent, inert carbonates.
For miners struggling to balance climate commitments with rising production targets, Arca’s model transforms waste into an ESG-driven revenue stream. “This is not just about reducing emissions,” said Sean Lowrie, Arca’s head of external affairs. “It’s about creating a trillion-dollar industry embedded inside mining.”
Three Technologies for Permanent Carbon Sequestration
Arca’s platform combines three complementary technologies designed to deliver measurable, permanent removals:
- Real-time monitoring: A digital MRV (monitoring, reporting, verification) system tracks carbon flux into tailings. Crucially, methodologies are aligned with International Organisation for Standardisation (ISO) protocols, ensuring credits are credible and tradable.
- Smart churning: Amphibious robotic rovers agitate tailings ponds, exposing fresh mineral surfaces. These react with CO₂ and water to form magnesium carbonate crusts that remain stable for millennia.
- Mineral activation (in development): Microwave processing fractures mineral lattices, exposing reactive elements that accelerate CO₂ capture. With nearly 99% of Earth’s carbon stored in rock, this step effectively fast-tracks natural processes that usually take thousands of years.
A $1.3 Trillion Carbon Credit Market
The scale of the opportunity is vast. According to Arca, legacy ultramafic mine waste alone could sequester 6.5 billion tonnes of CO₂. At an average carbon credit price of $200 per tonne, that equates to a $1.3 trillion market. Extending the model to all alkaline waste streams could quadruple potential removals.
Mining itself generates roughly 3 billion tonnes of waste annually—a recurring flow that could underpin a long-term carbon credit revenue model. For companies under mounting investor and community pressure, the dual value proposition is clear: generate new revenues and strengthen environmental license to operate.
“Waste piles can become one of mining’s greatest assets,” Lowrie noted.
Carbon Credits and Greenwashing Risk
Carbon markets face credibility concerns, with forestry offsets often criticized as temporary. Arca argues permanence and scientific verification set its approach apart.
“Forests burn, and direct air capture is prohibitively expensive,” Lowrie said. “But magnesium carbonate is chemically stable for 10,000 years. These are the highest-quality removals on the market.”
ISO-compliant monitoring gives mining firms confidence that credits will hold up under scrutiny from regulators, investors, and carbon auditors.
From Pilots to Industrial Scale
In 2023–24, Arca ran an 18-month demonstration at BHP’s Mount Keith nickel mine in Western Australia, validating integration into daily tailings management. Support from Canada’s Mining Innovation Commercialisation Accelerator and recognition at the Mine Decarbonisation Innovation Awards (2025) have since accelerated momentum.
The next step: a full-scale mineral activation prototype within 12 months. Successful deployment could embed carbon sequestration directly into industrial tailings circuits—turning a compliance cost into a cash generator.
Early Market Demand from Tech, Finance, and Aviation
Buyers are already circling. Microsoft, Stripe, JP Morgan, Swiss Re, and Airbus are all active in high-quality carbon removals. Microsoft alone has committed to erasing its historical footprint, making it a natural early customer.
Yet Lowrie positions sequestration as complementary, not a substitute: “Electrify haul fleets, shift to renewable power—then use sequestration for hard-to-abate emissions like blasting.”
Skillings Analysis
- Strategic upside: Arca reframes tailings from environmental liability to climate-positive asset. For miners under Scope 3 pressure, the reputational and financial benefits are significant.
- Execution challenge: Scaling mineral activation from lab to operational circuit will require substantial capital. Project finance models remain untested.
- Market dynamics: With voluntary carbon markets still fragmented, compliance-market clarity will determine adoption speed. Early-mover partnerships could lock in premium pricing and reputational edge.
Outlook
With industrial pilots underway and demand from Big Tech and finance intensifying, Arca is positioning itself at the intersection of mining and climate finance. If its mineral activation technology delivers at scale, the sector could see tailings rebranded—from a legacy liability into a cornerstone of carbon-negative mining.
As the December climate negotiations loom and compliance markets take shape, Arca’s next moves could redefine what it means for mining companies to have a “license to operate” in the low-carbon economy.
