• Categories:company news
• Author:
• Origin:
• Time of issue:2011-08-09 15:54
• Views:0

(Summary description)　　Magnesia refractories refer to refractories with magnesite as raw material, periclase as the main crystal phase, and MgO content of 80%-85%. The characteristics of magnesia refractory materials, compared with other refractory materials, the refractoriness is as high as 2000℃, and it has a higher load softening temperature, generally up to 1500℃～1650℃, but the thermal shock stability is not good. Magnesia refractory materials are divided into two categories: metallurgical magnesia and magnesia refractory products.

　　The thermal conductivity of magnesia refractory products is high, and the thermal conductivity decreases with increasing temperature; the coefficient of thermal expansion is large, but the expansion process is relatively gentle; it has strong resistance to alkaline slag containing magnesium oxide and calcium oxide, and has strong resistance to chemical attack.

　　Types of magnesia refractory products: magnesia bricks, magnesia silica bricks, magnesia alumina bricks, magnesia calcium bricks, magnesia carbon bricks, etc.

　　Magnesium brick: The most important product among alkaline refractory materials, with high refractoriness, and good corrosion resistance to iron oxides, alkaline slag and high-calcium fluxes. Magnesia bricks are divided into fired magnesia bricks and unfired magnesia bricks. The firing temperature of fired magnesia bricks is generally 1550℃～1600℃, and the firing temperature of high-purity products is 1750℃ or even higher. The unfired magnesia bricks are basically the same as the fired magnesia bricks except for the firing process. Magnesia-silica bricks: use periclase as the main mineral composition and forsterite as the matrix combination. Its performance is roughly the same as that of magnesia bricks, but its load softening temperature is higher than that of magnesia bricks (1600℃～1630℃), and its slag resistance is also better Great. Magnesia-aluminum brick: It is a product made by using calcined magnesia with less calcium as raw material, adding about 8% industrial alumina powder, using acid pulp waste liquid as a binder, and burning at 1580°C. Compared with magnesia bricks, magnesia alumina bricks have good resistance to rapid cooling and heating, and can withstand water cooling for 20-25 times or even more times. This is the outstanding advantage of magnesia alumina bricks. Magnesia-calcium bricks: magnesia is the main mineral composition, and tricalcium silicate and dicalcium silicate are combined. In addition to poor thermal shock stability, other performance indicators are superior to magnesia bricks. Magnesia-carbon bricks: use high-quality sintered magnesia and carbon materials as raw materials, pressed with various carbon binders, and have a series of excellent properties such as corrosion resistance and spalling resistance.