Following equity investments since March 2025, Rio Tinto and the Government of Québec now hold 53.9% and 46.1%, respectively, in Nemaska Lithium. These stakes stem from Rio Tinto’s acquisition of Arcadium and Québec’s commitment via Investissement Québec. As the majority shareholder, Rio Tinto has assumed direct management of Nemaska Lithium, applying its global standards and operational expertise in development, operations, sales and marketing to advance an integrated lithium business in Québec.
Partners will continue funding the lithium hydroxide plant under construction in Bécancour. As of the end of 2025, this plant was 60% complete and its engineering phase is finished. Commissioning is scheduled to begin in 2026, with first production targeted for 2028. Québec has committed up to US$200 million through equity subscriptions, while Rio Tinto plans to invest more than US$300 million in 2026 to support ongoing project development and commissioning activities.
Nemaska Lithium’s portfolio includes the Whabouchi spodumene mine in the Eeyou Istchee James Bay region and the Bécancour hydroxide plant. Jérôme Pécresse, Chief Executive of Rio Tinto Aluminium & Lithium, said that assuming a majority interest aligns with the company’s growth objectives and enhances its integrated lithium product offering. Rio Tinto is evaluating spodumene feedstock options from both Whabouchi and its wholly owned Galaxy mine, comparing logistics, quality and production costs to determine the optimal supply strategy. This assessment is expected to conclude during the first half of 2026.
In taking on day-to-day management, Rio Tinto will integrate its sustainability and environmental management practices to meet stringent regulatory requirements and foster positive community engagement. The company plans to leverage local supply chains and workforce, reinforcing economic development in the regions surrounding both the Whabouchi mine and Bécancour plant.
This development represents a significant step in building a regional supply chain for battery-grade lithium hydroxide and underscores support for the growing electric vehicle and energy storage markets.
Source: Rio Tinto
