Research and Application of High-Strength Wear-Resistant Castables for Blast Furnace Granulation Towers

Blast furnace granulation towers are crucial equipment in ironmaking for processing high-temperature molten slag. The high-temperature molten slag is rapidly cooled by water to form granulated slag, which is then separated from the slag through a settling tank, distribution tank, and rotary drum dewatering device, ultimately transforming it into reusable slag for use as cement raw material, achieving resource recycling and energy conservation and emission reduction.

Due to the high temperature, strong impact, and high corrosiveness of the granulation tower environment, the requirements for the high-temperature wear-resistant materials used in the lining are extremely high. While traditional cast steel plates and cast iron plates have high strength, they are prone to oxidation and corrosion at high temperatures, resulting in short service life and frequent maintenance cycles. Therefore, wear-resistant castables have gradually become an ideal alternative material for granulation tower linings.

I. Advantages and Development Direction of Wear-Resistant Castables

Compared with metal liners, wear-resistant castables offer advantages such as simple construction, good integrity, strong wear resistance, and long service life. During construction, a steel mesh is simply laid on the furnace surface, and then the wear-resistant castable is poured or applied to the lining to form a dense, wear-resistant layer.

However, conventional wear-resistant castables still have some problems in use, such as insufficient thermal shock stability, localized easy wear, and decreased high-temperature strength. To further improve performance, the research team developed a new type of high-temperature wear-resistant material using chromium corundum as the main raw material, aiming to significantly improve the overall lifespan and operational stability of the furnace lining.

II. Raw Material and Formulation Design of the Wear-Resistant Castable

The new wear-resistant castable uses fused chromium corundum as the main aggregate. Chromium corundum is produced by high-temperature smelting of alumina and chromium oxide, exhibiting high hardness, good toughness, and excellent wear resistance.

Chromium corundum powder, activated alumina powder, chromium oxide powder, and high-alumina cement are added to the matrix, supplemented with a water-reducing agent to improve fluidity. By adjusting the ratio of alumina micropowder to cement, the wear-resistant castable maintains high strength while possessing good workability and density.

After mixing, stirring, molding, curing, and firing, the samples underwent performance testing, including indices such as bulk density, apparent porosity, flexural strength, and compressive strength, to verify the comprehensive performance of the novel high-temperature wear-resistant material.

III. Performance Analysis and Results

1. Construction Performance

The novel wear-resistant castable exhibits good fluidity, meeting the requirements of on-site construction. The combination of alumina micropowder and water-reducing agent improves the uniformity of the slurry, resulting in a smooth casting process with no significant segregation and high construction efficiency.

2. Room Temperature Performance

After heat treatment, the bulk density of the material significantly increases, porosity decreases, and the structure becomes more compact. With the increase of alumina micropowder, the compressive and flexural strengths of the wear-resistant castable increase simultaneously, and its overall mechanical properties are superior to ordinary castables.

3. High-Temperature Performance

At 600℃, the high-temperature strength and wear resistance of the wear-resistant castable are further improved. Chromium corundum and high-alumina cement form CA and α-Al₂O₃ crystalline phases at high temperatures, enhancing the material's high-temperature structural stability and making it a high-performance high-temperature wear-resistant material.

IV. Practical Application Results

This novel wear-resistant castable was applied in the blast furnace granulation tower. During construction, the material exhibited good fluidity and strong adhesion, resulting in a dense furnace lining without cracks after molding. After long-term operation, the furnace lining surface showed minimal wear, with no peeling or structural damage.

Compared to traditional metal plates, the wear-resistant castable's service life is increased several times, maintenance frequency is significantly reduced, and downtime maintenance costs are significantly lowered, providing a reliable guarantee for the stable operation of the blast furnace system.

V. Conclusion

By using chromium corundum as the main raw material and optimizing the formula ratio, a novel wear-resistant castable was developed, possessing high strength, high density, and excellent wear resistance, classifying it as an advanced high-temperature wear-resistant material. Its main advantages include:

Excellent construction performance and simple operation;

Significantly improved strength at both room and high temperatures;

Strong wear resistance and thermal shock resistance;

Long service life and low maintenance costs.

The successful application of this new wear-resistant castable in blast furnace granulation towers provides important technical support for energy-saving, safe, and environmentally friendly operation in the metallurgical industry, and has broad application value.