Traditional iron production relies on carbon-intensive reductants like metallurgical coke, contributing significantly to greenhouse gas emissions. Low-carbon ironmaking technologies primarily use hydrogen-based reduction to produce direct reduced iron (DRI), leveraging green hydrogen from renewable electricity. Understanding iron ore behaviour during hydrogen reduction is essential for efficient and economical low-carbon processes. This study uses a custom bench-top furnace for hydrogen reduction of iron ore lump, pellets, and fines. High-resolution micro-computed tomography (µCT) offers non-destructive 3D insights into microstructural evolution, including porosity development, crack formation, and phase-specific responses. Combined with scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF), these analyses reveal how structural differences affect reduction outcomes and disintegration. Adjusting parameters like temperature ramp rates and gas composition can mitigate these impacts, enhancing low-carbon ironmaking efficiency.