Chrome Corundum Refractory Bricks

The main ingredients of chrome corundum refractory bricks are Al2O3 and Cr2O3, adding Cr2O3 to the Al2O3 single-phase refractory materials not only did not reduce the refractoriness of the materials, but the refractoriness increased with the increase of the Cr2O3 content.  

Adding Cr2O3 to the corundum material, as the temperature rises, Al2O3 and Cr2O3 gradually form a solid solution, so that the corundum particles and the matrix are tightly combined, and further form a ring-shaped solid solution zone on the surface of the corundum particles, making the material tightly bond between particles and particles, particles and fine powder at high temperature, and the bonding phase is aluminum-chromium solid solution phase, which has a high melting point and maintains bonding strength even at high temperatures. Therefore, chromium corundum refractory materials have strong mechanical properties at room temperature and high temperature.  

Cr2O3 is a high-quality component in refractory materials, which can form high melting point compounds with a variety of oxides. For example, Cr2O3 and Al2O3 can form a continuous solid solution. The melting point of this solid solution is above 2050℃. Cr2O3 and MgO/FeO form high-melting magnesia-chromium spinel/chromium iron spinel. Cr2O3 and Cu2O can form compounds with a melting point above 1600℃.  

In addition, Cr2O3 can also increase the viscosity of the slag, and the increase of the viscosity of the slag can slow down the penetration rate of the slag into the refractory. In summary, Cr2O3 can improve slag erosion resistance and anti-spalling properties.

1. High refractoriness, usually the refractoriness is above 1700°C.

2. Refractoriness under load about 1500-1550°C because of poor high-temperature intensity.

3. Strong ability to resist basic (alkaline) slag, can not contact with acid refractory material.

4. Thermal shock resistance, so keep the temperature of the furnace stabilized.

5. Poor Volume stability at high temperatures, must set aside appropriate expansion joint when laying bricks.

6. Strong ability of thermal conductivity, sometimes need insulating material.

With the development of modern smelting technology, hot blast stoves generally adopt high air temperature technology, and the service life of hot blast stoves is required to be longer: therefore, higher requirements are put forward for the comprehensive performance of refractory materials for hot blast stoves. Damage to refractory materials used in hot blast stoves is usually caused by thermal stress, chemical attack, and mechanical loading.

It is generally believed that an important reason for the damage of the hot blast stove is that the high-temperature creep resistance of the refractory material is poor, resulting in collapse, deformation, and cracking of the lining refractory material, thus causing widespread concern for low creep bricks for hot blast stoves.

Chrome corundum refractory bricks are widely used in glass kiln lining, drawing glass flow hole cover tile, and hot metal pretreatment devices, waste incinerators, coal slurry pressurized gasifier lining, and so on.

Wooden pallets, wrapped with plastic film & bundled belts