<p>To address the utilization challenges posed by solid waste coal gangue and explore the utilization potential of low-rank coal in different regions, this study employs coal gangue as the raw material and coals of different ranks (lignite, bituminous coal, and coke) as reducing agents to prepare Si–Al–Fe alloys through carbothermal reduction. First, the experiment characterized the differences in composition, crystallinity, pore structure, and CO₂ reactivity among the coals. The results indicate that low-rank lignite and bituminous coal possess higher specific surface areas, well-developed microporous structures, and higher amorphous carbon content, exhibiting significantly better CO₂ reactivity below 1200&#xa0;°C compared to high-rank coke. The carbothermal reduction of coal gangue revealed a consistent phase transformation pathway across different coal ranks: initial decomposition of composite oxides and reduction of Fe, followed by gaseous SiO serves as a medium, facilitating the formation of SiC on the surfaces of the raw material and the reducing agent. Then the SiC reacts with SiO further to produce Si. Notably, low-rank coals enhanced mass transfer of gaseous products by providing larger reaction areas and active sites, which facilitated a loose product layer. In smelting experiment using a DC arc furnace, an alloy with a composition of Si₆₃Al₁₇Fe₁₄ was successfully prepared using low-rank lignite as the reducing agent, indicating that the key reaction mechanism for the reduction of Si and Al involved the interaction between gaseous suboxides and intermediate carbides, while the feasibility of low-rank coal as a reducing agent for Si–Al–Fe alloy was verified.</p> Graphical Abstract <p></p>