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How can we improve the production quality of high alumina bricks?

More related products: Fused Cast AZS; Fused Cast Alumina Block; Fused Cast High Zirconia Block; Fused Cast Skid Rail Block

Production of high alumina refractory bricks generally use soft clay, this material has good plasticity, so the production of high alumina refractory bricks are generally used as a separating agent for soft clay. However, the free Al2O3 in clay and high alumina bauxite digested at room temperature, the secondary mullitization occurred at 1200 ℃, and the larger body shortened, the porosity of silicon increased and the strength decreased. Therefore, with guess clay powder participation in less than 5% is appropriate. The following is a detailed material ratio.

In addition, the high bauxite powder can be used as the separating agent; or the high bauxite powder and the clay powder can be prepared according to a certain proportion to prepare mullite for preparing the separating agent. With these separators can be prepared without secondary shortening of high alumina bricks.

High alumina brick mud generally use coarse, medium and fine three ingredients. The upper limit of coarse particles is generally 2 ~ 3mm, the participation of 40% ~ 50% (for shaped products, the upper limit of coarse particles can be reduced to 2 ~ 1mm) 1 ~ 0.1mm center particle participation amount of 10% to 20% is appropriate; <0.1mm powder participation should be controlled at 40% to 50%.

Spending theory indicates that properly increasing the coarse grain size and the amount of advancing bulk density, and easy to shape. When firing, the second mullite reaction near the material is weak and easy to sinter. However, there are certain limits to expanding the particle size. Assuming expanded to 4 ~ 5mm, prone to missing edge off angle, and the arrangement of the average level has been affected. Therefore, the largest particle size to 3mm is appropriate.

With the guesswork in the participation of fine powder sintering is conducive to the body, add the density of finished products. It is necessary to participate in the fines because the shortening of the sintering of the fines during sintering can weaken or counteract the shortening of the volume due to the second mullite reaction. However, excessive participation of fine powder, not only difficult to shape, but also prone to cracking, firing shorter, waste rate added. Therefore, the amount of fine powder to 40 to 50% is appropriate.

The center particles do not play the role of group skeleton of the particles, nor the sintering effect of fine powder. Therefore, the amount of central particle participation is generally limited to the minimum amount. However, the central particles can not be revoked in full. Assuming the withdrawal of finished products prone to cracking after burning, the appearance of poor quality, but also to the material disposal will bring some difficulties. In general, the center of particles involved in the amount of 10% is appropriate.

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