Do you know what is breathable corundum brick?

For refractory bricks, some use conditions are to take advantage of the product's high porosity and high air permeability. At present, argon-breathing corundum bricks for ladle bottom blowing are widely used in steel plants. Gas is used to blow metals, that is, corundum bricks for liquids. The same particle size is used, and the filler and binder are used to tightly bond the particles during the sintering process, so that the product becomes a solid block, and the same size of the particle material determines the shape and size of the pores. If it is necessary to increase the air permeability of the product, the particle size of the slag additive should also be added, and its shape should be the same as that of the filler.

 

The porous and ventilated corundum bricks used for blowing metals have certain advantages in using corundum magnesia. For industrial applications, 80% of fused alumina bricks can be used as granules, and a mixture of industrial alumina (65%) and refractory clay (35%) can be used as a binder. The binder must be 20%. It is finely ground together, and the content greater than 60 μm cannot exceed 1% to 1.5%. The mud is kneaded on a wet mill. The kneading is required for 10 minutes, and the moisture of the mud is 4.3% ~ 5%, and then sieved on a sieve with a sieve size of 5mm. The bricks are formed on a hydraulic press with a pressure of 35 MPa, and the density of the bricks reaches 2.60 g / cm3. The product is fired in a tunnel kiln or an inverted flame kiln. The firing temperature is 1570 ° C, and the temperature is maintained for 22 ± 2 hours.

There are many methods for manufacturing breathable corundum bricks. The 20% binder is made by grinding together corundum waste (60%) and clay (40%). The moisture content of the mud is 4% ~ 5%. It is 2.60 g / cm3: it is fired in the tunnel kiln for 86h, the maximum firing temperature is 1560 ℃, and it is kept at (5 ± 1) h.

 

Others use fused alumina as aggregate, pure calcium aluminate cement and SiO2 superfine powder as binder, phosphate as dispersant, and ultra-low cement castable technology.