Brick fireclay

Aggregate Basalt 0/1 Crushed brick Fireclay 0/1 Corund 0/1 Crushed glass ... 

Fireclay brick is the second most frequently used brick. It is usually described as meeting type H in ASTM C-279. They contain a higher proportion of alumina and lower percentages of silica and iron than do shale brick. Fireclay bricks have a higher absorption rate than shale bricks, although some manufacturers will provide a denser brick that will meet type L for absorption. These brick are usually selected for outdoor exposures where rapid thermal changes occur since they are less brittle than the shale brick. Since they have a low iron content, they are used in process equipment where this characteristic is important in maintaining product purity. 

The resistance against thermal spalling of fireclay and high alumina brick is indicated in Table 5. No standard test has been adopted for basic brick. Refractories composed of 100% magnesia exhibit poor thermal shock resistance, which is improved by addition of chrome ore. So-called direct bonded basic brick, composed of magnesia and chrome additions, exhibits good thermal shock resistance. 

Sihca brick and large fireclay shapes are fired in circular downdraft kilns. These kilns vary in diameter and can accommodate up to 150,000 23-cm bricks or their equivalent in other si2es. The complete burning cycle for a typical periodic kiln ranges from 21 to 27 days as compared with four to seven days for a tunnel kiln. 

Includes regular fireclay, semisilica superduty fireclay, ladle brick, and insulating firebrick (IFB) below 23. Includes high alumina, mulhte, and extra high alumina brick. 

High Alumina Refractories. The desired alumina content, from 100% to just above 45%, is obtained by adding bauxites, synthetic aluminosihcates, and synthetic aluminas to clay and other bonding agents. These refractories are used in kilns, ladles, and furnaces that operate at temperatures or under conditions for which fireclay refractories are not suited. Phosphate-bonded alumina bricks have exceptionally high strength at low to intermediate temperatures and are employed in aluminum furnaces. High alumina and mullite are used in furnace roofs and petrochemical apphcations. 

Tne insulating firebrick is a class of brick that consists of a highly porous fire clay or kaolin. Such bricks are light in weight (about one-half to one-sixth of the weight of fireclay), low in thermal conductivity, and yet sufficiently resistant to temperature to be used successbilly on... 

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. 

Procedure. The method to be described is especially suitable for ceramic materials such as fireclay, firebrick, or silica brick. The finely ground sample should be dried at 110 °C. The weight of sample to be employed depends largely upon the silica content of the material, since not more than 35 40 mg of silica should be present in the aliquot employed for the determination. For samples... 

Fireclay bricks are used in kilns, malleable-iron furnaces, incinerators, and many portions of metallurgical furnaces. They are resistant to spalling and stand up well under many slag conditions but are not generally suitable for use with high-lime slags or fluid-coal-ash slags or under severe load conditions. 

Temp, °C Fireclay Silica Brick Magnesite Chrome Forsterite Mullite Cristobalite Periclase Corundum... 

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