Refractory brick classification, what is breathable corundum brick?

For refractory bricks, some conditions of use is the use of products with high porosity and high permeability. At present, the steel widely used steel bottom blowing argon breathable corundum brick, with gas blowing metal, that is, with gas blowing liquid with corundum brick. Using the same particle size, the use of filler and binder in the sintering process to tightly adhere to the particles together, so that products become a solid block, and the same size of the granules determine the shape and size of the pores. If it is necessary to increase the air permeability of the product, it is also necessary to add the addition of the embers. The particle size should be the same as the size of the filler, and the shape is the same as that of the filler.

Used to blow the metal porous breathable corundum brick, with corundum magnesia has some advantages. Industrial applications of breathable corundum brick can be used 63 with fused corundum 80% made of pellets, industrial alumina (65%) and refractory clay (35%) of the mixture as a binder, 20%, the binder in the cylinder mill In the common fine grinding, greater than 60μm content can not exceed 1% to 1.5%. The mud is kneaded on a wet mill, requiring a kneading of 10 min, a moisture content of 4.3% to 5% of the clay, and then sieving on a sieve having a mesh size of 5 mm. Brick in the pressure of 35MPa hydraulic machine molding, brick density of 2.60g / cm3. Products in the tunnel kiln or inverted kiln firing, firing temperature 1570 ℃, insulation 22 ± 2h, the total firing time can not be less than 150h.

There are a variety of methods for the manufacture of breathable corundum bricks, 20% of the binder is corundum waste (60%) and clay (40%) common grinding system, mud moisture 4% to 5%, pressed brick density 2.60 g / cm3 :, in the tunnel kiln after 86h firing, the maximum firing temperature of 1560 ℃, insulation (5 ± 1) h.

And some use of fused corundum as aggregate, pure calcium aluminate cement and SiO2 superfine powder as a binder, phosphate as a dispersant, the use of ultra-low cement castable process