High-duty fireclay

Red and blue acid-resistant bricks are resistant to all inorganic and organic chemicals, except for hydrofluoric acid and hot concentrated caustic alkalis. Acid-resistant fireclay bricks are used for conditions involving elevating temperatures and corrosive condensates. Highly vitrified materials such as chemical stoneware, porcelain and basalts are used for extremely severe duties or where contamination of the process liquors is undesirable. 

Modem firebrick (from fireclay, kaolin) and silica brick are available in many compositions and many, many shapes for a wide range of apphcations and to meet varying temperature and usage requirements. High-density, double-burned, and super-duty (low-silica) firebrick have high-temperature heat resistance, but relatively high heat loss thus, they are usually backed by a lower density insulating brick. 

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