1. Corrosion resistance is divided into two types: alkaline and acidic
Corrosion resistance is divided into two types: alkaline and acidic, and acid and alkali corrosion is also common. Therefore, it is necessary to understand the properties of refractory bricks of different materials in order to make better selections. The types of refractories bricks are divided into silicon-aluminum series, magnesia series, chromium series, siliceous series, calcium aluminate series, composite material series, corundum series, and aluminum-carbon series.
2. Refractory brick type series
High alumina bricks contain mullite, which has good thermal shock but poor corrosion resistance. Corundum bricks have good resistance to alkali metals and have small volume changes. If it is under high temperature and alkali metal concentration, high alumina bricks cannot be used as lining.
Magnesia-chromium and chromium-corundum refractory bricks have high refractory resistance and high high-temperature strength. It has good resistance to alkaline high temperatures, good material density and thermal bonding strength of magnesia-chromium bricks, low porosity, and good resistance to slag erosion. Although chromium fire bricks have strong resistance to alkali corrosion and even good resistance to acid corrosion, chromium is a toxic substance and has been mentioned on the agenda of public hazards. Chromium products should still be used with caution.
Calcium aluminate series has excellent compatibility with aluminum products, good stability in high-temperature reducing atmospheres, and good corrosion resistance in alkaline environments.
The crystal structure of corundum refractory firebricks can absorb alkali metal ions between layers, and the volume of the refractory fire bricks does not change significantly. Compared with other refractory materials, its volume stability is higher when it resists alkali erosion.
Magnesia-alumina spinel bricks have a stable structure. It is resistant to high temperatures, especially when used in an alkaline atmosphere, and has very good resistance to alkali erosion. In addition, refractory magnesia-aluminum spinel bricks have low thermal conductivity, small thermal expansion coefficient, high strength, high hardness, strong impact resistance and alkali erosion resistance.
Composite refractory bricks have relatively good resistance to alkali corrosion. Composite refractory fire bricks have good thermal shock stability, corrosion resistance, wear resistance and good slag corrosion resistance. Moreover, zirconium corundum composite bricks also have strong resistance to acid corrosion.
3. Aluminum carbon series prevents lining from embrittlement and damage
Aluminum carbon series refractory bricks are mostly used in high-temperature furnace bottoms. In reducing atmosphere, they have a low resistance to alkali metal erosion. They can not only slow down the alkali corrosion process, but also adhere to refractory ash and slag, preventing the lining from being brittle. Destroy.
The above series of refractories bricks have different properties. After understanding them, you can choose appropriate refractory fire bricks according to the conditions of different furnace linings.
