Influence mechanism of pore structure evolution on oxygen consumption dynamics during low-temperature oxidation of igneous metamorphic coal

• Igneous metamorphic coal exhibits enhanced spontaneous combustion tendency due to altered pore structure and oxygen consumption dynamics. • Oxidation reduces specific surface area and suppresses structure complexity increase, with effects more pronounced at higher metamorphic degrees. • Thermally metamorphic coal shows accelerated oxygen consumption, with oxidation amplifying differences in reaction rates compared to raw coal. • Pore structure evolution (increased volume/complexity, reduced uniformity/connectivity) synergistically enhances oxygen consumption capacity.