Amorphous carbon nanotubes incorporated MgO-graphite composite with enhanced properties for steel making furnaces

Abstract

Conventional MgO-graphite composite used in steel ladles suffer drawbacks like limited lifetime due to slag corrosion and inherent tendency of rapid oxidation of carbon. Carbon content of MgO-graphite refractories was varied by replacing graphite partly by amorphous carbon nanotubes to decrease the total carbon content keeping the surface area of carbon the same or larger. The structural and compositional characterizations were performed by X-ray diffraction and energy dispersive analysis of X-rays. The Fourier transformed infrared and Raman spectroscopies were used to find bonding information and distinctive carbon phases. Distribution of amorphous carbon nanotubes within MgO matrix and its nature of attachment were studied by field emission scanning electron microscopy and transmission electron microscopy respectively. The cumulative volume of the large pores decreased significantly by incorporation of amorphous carbon nanotubes. Cup test using the composite material with actual molten slag indicated significantly less penetration of slag in the nanocarbon based nanocomposite.