Silicon carbide bricks are advanced refractory materials made of SiC as the main raw material, with a series of excellent properties such as high strength at normal temperature and high temperature, large thermal conductivity, small thermal expansion coefficient, good thermal shock resistance, excellent high temperature wear resistance, and strong resistance to chemical erosion, etc. Widely used in steel industry, non-ferrous metallurgy, petrochemical industry, electric power, ceramics and aerospace fields.
Silicon carbide bricks can be divided into oxide bonded (clay bonded, mullite bonded, SiO2 bonded), nitride bonded (Si3N4 bonded, Sialon bonded), self bonded (β-SiC bonded and recrystallized silicon carbide) and silicon infiltration reaction sintered silicon carbide bricks according to the bonding method.
Clay-bonded silicon carbide bricks
Clay-bonded silicon carbide brick is made of coarse, medium and fine silicon carbide in accordance with the particle level ratio, first dry mixed evenly before adding clay and shaped by brick press. After drying for 2-4 days, the bricks are fired in a tunnel kiln with a firing temperature of 1400℃. This kind of brick has high thermal conductivity, small coefficient of thermal expansion, thermal shock resistance and good wear resistance.
High alumina silicon carbide brick
High alumina silicon carbide brick is added to the billet with fine powder, the addition amount is 30%, the final firing temperature is 1370-1480℃, and the heat preservation is 6-8 hours. This kind of refractory brick has good thermal shock resistance, good thermal conductivity and high strength.
Corundum silicon carbide brick
Corundum silicon carbide brick is made of brown corundum as aggregate, add 10% silicon carbide fine powder, phosphoric acid as binding agent, pressed and shaped by brick press, dried and fired by high temperature, firing temperature is 1450℃. This corundum silicon carbide brick has high strength, good wear resistance, strong resistance to slag erosion and good resistance to thermal shock.
| ltem | Oxide bond SiC brick | Green SiC brick | Corundum silicon carbide brick | Mullite silicon carbide brick | High alumina SiC brick |
| SiC, % | ≥90 | ≥90 | ≥70 | ≥65 | ≥20 |
| Al2O3, % | - | - | - | ≥20 | ≥55 |
| Fe2O3, % | ≤0.6 | ≤0.6 | ≤1.0 | ≤1.0 | ≤1.5 |
| Bulk density, g/cm3 | ≥2.6 | ≥2.6 | ≥2.7 | ≥2.3 | ≥2.5 |
| Apparent porosity, % | ≤17 | ≤17 | ≤22 | ≤20 | ≤20 |
| Cold crushing strength, MPa | ≥100 | ≥100 | ≥100 | ≥80 | ≥80 |
| Refractoriness under load (0.2MPa,0.6%) | ≥1650 | ≥1650 | ≥1700 | ≥1600 | ≥1600 |
