This study concerns itself with the carbothermic reduction of mill scale, which is an iron oxide layer that forms on the surface of materials subjected to hot rolling or continuous casting. The mill scale is pelletized before undergoing reduction in a rotary kiln. The final product is direct reduced iron pellets with different amounts of metallic iron. Chemical and XRD (X-Ray Diffraction) analyses are carried out on samples obtained at different periods of time during the reaction. The effect of temperature, reductant type and amount of reductant is investigated by comparing the results reached by performing experiments with different parameters. Metallization degree, which is the ratio of metallic iron to total iron, and phase structure of the samples provide the necessary data to determine the effect of the parameters. It was found out that different types of reductant offered different temperature and stoichiometry dependency with regards to the reduction potential they provide.