There are many types of commonly used refractory castables, which can be divided into many types according to different classification standards. The following are some common refractory castables:
1. Classification by bonding method
1. Hydration bonded refractory castables
Silicate cement bonded refractory castables: ordinary silicate cement, slag silicate cement, etc. are used as binders, mixed with refractory aggregates and powders. The use temperature is 700~1200℃, which can be used for overall load-bearing heat-resistant structures and kiln linings.
Aluminate cement bonded refractory castables: It has the characteristics of fast hardening, high strength, good thermal shock stability, and high refractoriness. The use temperature can reach about 1800℃, and it is widely used in metallurgy, petrochemical and other industrial sectors.
Low cement bonded refractory castables: The addition of calcium aluminate cement is less than 8%, with the characteristics of high density, low porosity, high strength, etc., suitable for blast furnace tapping channels, steelmaking ladles and other parts.
Ultra-low cement combined refractory castable: The amount of aluminate cement used is less, and the performance is better than that of low cement refractory castable, which is widely used in high temperature parts such as blast furnace iron trough.
2. Chemically combined refractory castable
Water glass combined refractory castable: It is an air-hardening refractory material prepared with water glass as a binder and various refractory aggregates in a certain proportion. It has the characteristics of small strength loss under high temperature, good thermal shock resistance, good high temperature wear resistance and good high temperature corrosion resistance. The maximum use temperature is not more than 1400℃.
Phosphoric acid and phosphate combined refractory castable: It is a new type of refractory material prepared by phosphoric acid or phosphate solution with refractory aggregate and powder in a certain proportion, and has good performance.
2. Classification by aggregate material
Silica refractory castable: It uses silica, quartz sand, etc. as the main raw materials.
Semi-silica refractory castable: It contains siliceous and clay raw materials.
Clay refractory castables: with clay, shale, etc. as the main raw materials, the use temperature is 700~1200℃, and can be used for overall load-bearing heat-resistant structures and kiln linings.
High-alumina refractory castables: with high-alumina bauxite, bauxite, etc. as the main raw materials, often used in kiln linings with high temperatures exceeding 1300℃, with low price and high overall strength.
Corundum refractory castables: with corundum as the main raw material, it has the characteristics of high strength, high load softening temperature and good slag resistance, and the general use temperature is 1500~1800℃.
Magnesium refractory castables: with magnesia, magnesite, etc. as the main raw materials.
Spinel refractory castables: with spinel as the main raw material.
Special aggregate refractory castables: such as silicon carbide, chromium slag and zircon.
3. Classification by performance characteristics
High-strength wear-resistant castable: It is an unburned refractory material. Compared with the fired refractory products, its refractoriness is slightly lower, but it has high strength at room temperature and good resistance to cracking.
Lightweight thermal insulation refractory castable: It uses lightweight porous refractory materials as aggregates and admixtures, adds binders to form a mixture, and then adds water for construction. It is characterized by light weight, low bulk density, and low thermal conductivity. It is often used in the insulation layer of furnaces and the lining of furnace covers.
Non-stick aluminum castable: It uses high-purity mullite, andalusite, and sillimanite as base materials, and has the characteristics of high bulk density, high strength, and good thermal shock stability. By adding an appropriate amount of "non-wetting agent", the wettability of aluminum, alloys, and slag to refractory materials can be greatly reduced.
Self-flowing refractory castable: It has the characteristics of good construction performance and excellent use performance. It is mainly used in various high-temperature industrial kilns with complex structures and other difficult construction locations.
4. Classification by use part
Special castable for kiln mouth: refractory and thermal shock resistant castable used at the head and tail of rotary kiln, with good thermal shock reliability, easy bonding to kiln skin, wear resistance and other characteristics.
Special castable for ladle: such as corundum spinel prefabricated block, using fused white corundum, plate corundum and sintered magnesium aluminum spinel as the main raw materials, with high strength, corrosion resistance, anti-stripping and other characteristics.
Special castable for boiler furnace: using high-quality high-alumina bauxite clinker as the main raw material, calcium aluminate cement and microsilica powder as binder, adding appropriate amount of silicon carbide wear-resistant particles and dispersant.
There are many types of commonly used refractory castables, each type has its own unique characteristics and application areas. When choosing refractory castables, it is necessary to make reasonable choices according to the specific use environment and requirements.
HOME