WEAR OF MgO-C REFRACTORIES IN EBT TYPE FURNACES EXPERIENCED AT IRANIAN MOBARAKEH STEEL PLANT

摘要

Mobarakeh Steel Company produces 3 million tons of steel annually with eight 180 tons EBT furnaces. Different types of magnesia-carbon refractories have been employed at slagline during last 5 years. In the present study the wear and corrosion of MgO-C refractories of these furnaces have been studied via post-mortem analysis of used bricks and the observation of operational effects. Laboratory corrosion tests were also arranged to investigate the effect of slag chemistry and the mechanism of chemical corrosion. Characterization of different magnesia-carbon bricks clarified that the crystal size, type and chemistry of magnesia as well as graphite structure have the main influence on corrosion resistance. The CaO:SiO2 ratio in slag also plays a vital role in the wear of slagline refractories. The iron oxide content of slag also has a major role in graphite oxidation. Of metallurgical parameters, the electric power input and the contact time have great influence on refractories life. The results will be discussed with emphasis on particular operational factors in Mobarakeh steel plant.