Magnesia refractory bricks

Classification of magnesia refractory bricks

(1) Ordinary magnesia bricks can withstand high temperature heat load, fluid flow impact and chemical erosion of molten steel and strong alkaline slag. Therefore, the lining of smelting furnaces subjected to the above effects, such as open hearth, converter, electric furnace, iron furnace, non-ferrous metal smelting furnace, hearth of soaking furnace and heating furnace, as well as cement kiln and glass kiln regenerator, etc. , can use this kind of refractory products. However, due to its poor thermal shock resistance, it is not suitable for use in places where the temperature changes rapidly. In addition, due to its large thermal expansion and low softening temperature under load, it must be suspended when used on the top of high-temperature kilns.

(2) Magnesia-calcium bricks and magnesia-silica bricks can be used in the same conditions as ordinary magnesia bricks. However, because these products have a higher softening temperature under load, and the performance of magnesia-calcium bricks against alkaline slag is better, and magnesia-silica bricks also have the ability to resist various slag, so the scope of application is wider. For example, magnesia-calcium bricks are more effective when used in places eroded by alkaline slag. However, this product has poor thermal shock resistance and is easy to crack. The magnesia-silica brick can also be used as an open hearth, or a lattice brick with less temperature change in the upper part of the regenerator of a glass melting furnace.

(3) Magnesia-alumina bricks can replace ordinary magnesia bricks and have good effects in the above-mentioned parts. Therefore, the products have excellent thermal shock resistance and high softening temperature under load, so they can also be used in places subject to periodic temperature fluctuations, such as open hearth furnace tops, high temperature zones of cement kilns and regenerators of glass melting furnaces. The effect is obviously better than that of ordinary magnesia bricks, and it can also be used for the top of other high-temperature kilns such as high-temperature tunnel kilns.

(4) Magnesia-chrome bricks should be used under conditions of high temperature, slag corrosion and rapid temperature changes. It is more effective when used in similar working conditions as magnesia alumina bricks, such as open hearth furnace tops, non-ferrous metal smelting furnaces, high temperature zones of cement kilns and glass kiln regenerators. But it should not be used under the conditions of frequent changes in the atmosphere.

(5) Magnesia-carbon bricks have good slag resistance, are not easy to produce structural spalling, and have good thermal shock resistance and are not easy to produce thermal cracking, so they should be used in places with severe slag corrosion and sudden temperature changes. This kind of product has now become the main material of oxygen steelmaking converter lining and electric furnace wall, and is also widely used in ladle. However, this material should not be used directly in a strong oxidizing atmosphere.

(6) Directly combined with magnesia bricks It has high high temperature strength and excellent corrosion resistance. It is used in places exposed to high temperature, heavy load and slag corrosion, and its use effect is generally better than the above ordinary magnesia refractory products.