Magnesia-carbon bricks are shaped refractory product consisting mainly of magnesia and has a typical carbon content of 5 per cent to 20 per cent. The bonding system is based on resin (both phenol formaldehyde and novolak) and various pitches (coal tar and petroleum) and the products are tempered at 200-300°C. The magnesia-carbon bricks have an excellent technical performance, including high slag resistance and a long overall service life. The reason for the performance increase was the change in the type of magnesia. Initially, the bricks were manufactured with standard DBM, then with higher crystal DBM and currently a combination of sea water magnesia (SWM) and sintered magnesia is employed. The purity and nature of carbon have significant influence on the performance of the bricks. Various types of antioxidants have been developed which alone or in combination have been proved to be more effective. Selection and quality of resin binders significantly influence the brick properties and in turn the performances. Recent developments is addition of spinels and other additives like carbonaceous resin powder etc and have been proved beyond any doubt the improvement in performance.
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