What is the definition of alkaline brick?

Basic refractory refers to the refractories with magnesium oxide, calcium oxide or magnesium oxide and calcium oxide as the main components. It is mainly used for thermal equipment such as alkaline steelmaking furnace, nonferrous metal smelting furnace, glass kiln and cement kiln. There are many varieties in basic refractory, which can be divided into magnesium oxide, magnesium spinel, dolomite, olivine and limestone according to the chemical mineral composition. If classified by other methods, it can be divided into fired alkaline refractory products, non-caustic refractory products and fired oil-immersed alkaline products. Non-caustic products refer to tar bonded products, including asphalt bonded magnesium bricks, dolomite bricks and magnesium dolomite bricks, and fired oil-immersed alkaline products refer to fired products impregnated with asphalt, including oil-immersed magnesium dolomite bricks, magnesium bricks, dolomite bricks and lime bricks. Basic refractory has high fire resistance, strong resistance to alkaline slag and iron slag, high thermal expansion rate, poor thermal shock stability, poor hydration resistance and low steam pressure at room temperature. When working at high temperature and under reduced pressure, refractories are lost due to volatilization, and the volatilization speed is directly proportional to the vapor pressure of refractories. The greater the relative molecular mass of gas phase, the greater the volatilization. Basic refractory is a poor conductor of electricity at room temperature. With the increase of temperature, the resistivity decreases and the conductivity increases. Basic refractory did not use much in the whole19th century, and the earliest use of magnesium bricks can be traced back to 1868. With the discovery and mining of mines in Austria, the application of magnesia bricks increased rapidly after 1880. 1900 or so, magnesium brick has been used in converter, open hearth furnace, mixer furnace and cement kiln, which has solved the urgent problems in metallurgy, and its application has continued to increase to 1930. At the beginning of 1930, magnesium-chromium products appeared almost simultaneously in the commercial markets of North America, France and Britain. The earliest patent appeared in Britain 19 15, but it was not put into production in time due to the influence of World War I.