<p>Nickel is a critical metal with broad applications in stainless steel and nickel-based alloys. In recent years, its rapidly growing use in secondary batteries has become particularly important, underscoring its strategic role in enabling low-carbon, green, and sustainable societal development. As high-grade nickel sulfide resources become increasingly scarce and global demand for nickel accelerates—fueled by the expansion of clean energy technologies—there is a pressing need to develop environmentally benign extraction strategies for low-grade nickel sulfide ores to safeguard the stability and sustainability of the global nickel supply chain. Here we report a low-temperature predominantly solid-state process for extracting nickel from unconventional, low-grade ultramafic ores, estimated to contain approximately 45 million tonnes of untapped nickel. The method leverages cheap metallic iron as a nickel getter offering a sustainable pathway for high-value nickel recovery aligned with decarbonized metal production. The process produces ferronickel alloys (16-24% nickel) with several key advantages, including rapid processing time ( ~ 3 hours), low operational temperatures ( &lt; 950 °C), and the elimination of SO₂ emissions. Temperature, atmosphere, and iron addition were tailored to create favorable thermodynamic conditions within the reactor, enabling selective partitioning of nickel into metallic alloys while effectively sequestering sulfur as stable solid sulfide phases. Controlled tuning of alloy particle size and morphology facilitates efficient separation from gangue, yielding a ferronickel which can be converted to battery-grade nickel through conventional refining. This method, verified to mini-plant scale broadens the technological landscape of nickel extraction and contributes to a more equitable and resilient global nickel supply chain.</p>