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Magnesia bricks properties

What is the main purpose of magnesia bricks? Magnesia bricks are rarely used by us. It is different from ordinary building bricks. Magnesia bricks have very good fire resistance properties. In addition to being used as building bricks, there are other uses. Then What are the properties of magnesia bricks?

Main components of magnesia brick

The main component of magnesia brick is magnesia, and the main crystal is periclase, which accounts for 80%-90% of the mass of magnesia brick.

The properties of magnesia bricks

1. Because the main crystal of magnesia brick is strong basic periclase, it has high density, low moisture, high molding pressure, low apparent porosity and high bulk density. Therefore, magnesia bricks have the characteristics of multi-mineral composition, strong alkalinity and high density.

2. Magnesia brick is a typical alkaline refractory material, which has strong resistance to alkaline slag erosion.

3. The melting point of periclase is as high as 2800℃, so the refractoriness of magnesia brick is also very high, generally reaching above 2000℃.

4. The softening temperature under load of magnesia brick is much lower than refractoriness, about 1500℃.

5. The thermal conductivity of magnesia bricks is good, but the thermal conductivity decreases significantly with the increase of temperature, that is, magnesia bricks have good thermal conductivity and low heat preservation.

6. The thermal expansion of magnesia brick is large, and the coefficient of linear expansion increases with the increase of temperature. The thermal shock stability of magnesia brick is poor, and the number of water cooling is only 2-3 times.

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Classification of magnesia bricks

Magnesia bricks are generally divided into two categories: sintered magnesia bricks and chemically bonded magnesia bricks. Magnesia bricks with high purity and firing temperature are called direct-bonded magnesia bricks due to the direct contact of periclase grains; bricks made of fused magnesia as raw materials are called fused re-bonded magnesia bricks.

The use of magnesia brick

Magnesia bricks are widely used in steelmaking furnace linings, ferroalloy furnaces, and iron mixing furnaces in the iron and steel industry due to their good high temperature performance and strong resistance to alkaline slag; Industrial lime kiln; glass industry regenerator lattice and heat exchanger; high temperature calcining kiln, shaft kiln and tunnel kiln in refractory industry, etc.

Precautions

Although the raw materials and products of magnesia bricks have been calcined at high temperature, they are still hydratable. Magnesia bricks are less resistant to hydration at high temperatures. So in any case, pay attention to waterproof and moisture-proof.