Cement rotary kiln refractory materials magnesium aluminum spinel brick

Posted by ariel li on November 7th, 2017

Magnesia-alumina spinel refractory brick is high purity magnesia and pre-synthesized magnesium spinel as the main 6 material, the reasonable grading, high pressure molding, high temperature firing obtained products. Its characteristics are high, high strength, corrosion resistance, low coefficient of thermal expansion, thermal shock resistance, is the ideal transition from cement transition zone refractory materials for sale.
Magnesia-alumina spinel production of ingredients in the amount of magnesium aluminate spinel is not more good female, with the increase in the amount of spinel thermal shock resistance becomes better, but due to mismatch expansion will make g degrees (especially anti-fracture Strength) to Alz05 as the standard, the product A120: should not be large; 15% -20%, preferably 10% -18%, which is consistent with the experimental data of magnesia aluminum brick.
Magnesium aluminum tip stone brick main impurity is so z, should not exceed 1.5%.
Over the past twenty years, people have been seeking to replace magnesia-chrome bricks in addition to six valence-polluting technology, first of all, looking to the periclase spinel brick. The initial report was optimistic but gradually came the different message from the cement plant: "The kiln skin is not found." The eutectic temperature of the original spinel brick 4 cement is close to (slightly lower) the firing temperature of the cement. This is fatal, so spinel brick kiln lining in our cement kiln back to 15 ~ 20m to reach the transition zone, occupy the original high-alumina brick or ordinary magnesia-chrome brick position.
The academic community agreed that re20J affect the product's resistance to atmospheric changes, spinel brick in the transition zone is better than magnesia-chrome brick, one of the explanations is k205 content Below the M-K line, however, the addition of 4% re20J to spinel bricks improves the brittleness of bricks. When the expansion rate of only 113%, flexural strength 12MPa, will be. 05P kiln 38-40m area use 8 months wear 30mm, and commonly used spinel brick wear amount is 80 "120mm, and said that this high-speed rail bricks for burning belt can hang the kiln skin.
Spinel thermal shock resistance, anti-B 'alkali corrosion, acid gas erosion resistance, anti-atmospheric ability to change are better than ordinary magnesia chrome brick, but on the cement rotary kiln transition belt and discharge belt with refractory brick suppliers, Should also have a small thermal conductivity, good wear resistance, anti-shear fracture capacity, which determines the availability of spinel brick.

Wear resistance is poor, in the 2500t kiln can run stably for more than 8 months Feng Mao Wei angle.
China periclase spinel brick ingredients, the use of sintered high purity magnesia, mid-range magnesia and synthetic spinel sand (5i020 6% -20%), thermal shock resistance indicators are generally more than 10 times, the best of 2D Times or more. However, the high temperature flexural strength (1400Y, o.5h), roughly 2-3MPa, most products less than 3MPa, which is spinel brick to be improved technology. There are no national standards for the sharp stone blocks used in cement kilns, and all the manufacturing enterprises use each other for reference to form the spinel brick used in China's cement rotary kiln.
Spinel brick has the advantage of good thermal shock resistance, the use of clinker reaction during the spinel can form a thin layer of calcium aluminate protective layer, so that the liquid is not easy to penetrate, anti-spalling performance ratio Direct combination of magnesium chrome brick good. In the cement rotary kiln cooling zone and transition zone service life than the direct combination of magnesia-chrome brick to double. But slightly less resistant to erosion in the direct combination of magnesia-chrome brick. At the same time, spinel brick easy hydration, thermal conductivity larger kiln cylinder temperature than the use of direct combination of magnesia-chrome brick high.


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