Influence of CaO-SiO2-Al2O3 Ternary Oxide System on the Reduction Behavior of Carbon Composite Pellet: Part II. Morphological Properties

Carbon composite pellets composed of hematite, synthetic graphite, and oxide system were reduced at 1773 K (1500 °C) in a laboratory-scale horizontal tube furnace. The morphological properties of produced pellets after reduction were examined using light optical microscopy and a scanning electron microscope. Microscopic observation confirmed the correlation between morphological change of pellets and compositional difference of CaO-SiO₂-Al₂O₃ ternary oxide systems. Samples were also analyzed by X-ray diffraction to investigate phase change during the reduction process. The impact of oxide chemistry was established as each pellet illustrated different states of iron oxide as a function of time. In addition, the surface area was measured by the BET-N₂ absorption method to clarify the reaction mechanism which is significantly affected by physical contact.