Evaluation of Refractory Performance of Basic Castables Containing Magnesium-Aluminate Sol-Gel Coatings on Graphite

A study was conducted to compare the properties of carbon-containing basic castables that incorporated graphite with and without a magnesium aluminate sol-gel coating. A thin sol-gel coating of magnesium aluminate spinel was prepared from inexpensive precursors. The castable batch containing hydrophilic coated graphite required less water (9.5 mass-%) for mixing than the uncoated graphite (12.5 mass-%). Basic castable containing coated graphite showed better retention of graphite inside its refractory matrix. Consequently, slag corrosion and penetration resistance were noticeably improved in the coated graphite sample. X-ray diffraction, scanning electron microscopy and investiga-tion of physical properties were performed on the castables at different temperatures to confirm the benefits of spinel-coated graphite.