Arca–Giga Metals 220 Mt CO₂ plan at Turnagain: tailings design lens for engineers
Reviewed by Tom Sullivan
First reported on International Mining – News
30 Second Briefing
Arca Climate Technologies and Giga Metals have signed a 10-year agreement, dated 9 January, giving Arca exclusive access to tailings and waste rock at the Turnagain nickel project in British Columbia, jointly advanced with Mitsubishi Corporation. Arca will evaluate in-situ and ex-situ mineral carbonation of ultramafic mine wastes for up to 220 Mt of carbon dioxide removal, using industrial mineralisation processes integrated with planned tailings storage. The work could materially affect tailings design, waste rock handling and long-term closure strategies for the large-scale nickel sulphide operation.
Technical Brief
- Integration of industrial mineralisation with tailings handling could alter deposition geometry, drainage and consolidation behaviour.
- Waste rock stockpile layout and lift sequencing may be re-optimised to maximise gas–rock contact for in-situ uptake.
- Long-term closure concepts will need to incorporate post-closure monitoring of carbonation performance and geochemical stability.
- Similar ultramafic mining projects may benchmark Turnagain’s approach when evaluating carbon removal in mine planning.
Our Take
The related 10‑year agreement giving Arca exclusive access to roughly 1.3 Bt of ultramafic waste rock at the Turnagain nickel project suggests this 220 Mt CO₂ removal estimate is underpinned by a very large, long‑life tailings resource rather than a short pilot-scale opportunity.
Within our Mining coverage, Canada‑based nickel projects like Turnagain are increasingly framed as low‑carbon or carbon‑negative alternatives to Indonesian supply, which has become more uncertain and costlier following recent reports of potential 2026 ore quota cuts.
Mitsubishi’s presence alongside Giga Metals in British Columbia nickel stories in our database typically aligns with strategic positioning for low‑carbon battery metals offtake, so a material CO₂ removal potential at Turnagain could strengthen its appeal in future supply chain negotiations.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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