A comparative study on the reduction of mill scale from continuous casting processes

Jn this study, iron and iron based alloys (Fe, Fe-Ni, Fe-Cr-Ni, etc.) were produced by using metallothermic and carbothermic reduction of continuous casting mill scale. Mill scales are an oxidised layer of steel alloys containing iron oxide, which includes +2, +3 values, forming on the surface of slabs and billets during annealing in heating furnace at integrated iron and steel milling plants and continuous casting units. In the metallothermic experiments, different ratios of starting mixtures and addition of the reductant powders (Al, Si, Mg) were examined, and their effects on the metal recovery and alloy compositions were carried out. In the carbothermic experiments, direct reduction experiments were conducted with different types of reductant in various amounts and at various temperatures. Raw materials and obtained metallic and slag phases were characterized by using chemical analysis, XRD, XRF and EPMA/WDS techniques. Results were compared to determine the most effective reduction process.