Fused corundum is a product produced by smelting high-quality bauxite in an electric arc furnace at temperatures exceeding 2000°C. The resulting product is a crystalline material with high purity, high hardness and extraordinary thermal properties.
Raw materials: High-quality bauxite is the main raw material for the production of fused corundum.
Melting Process: Bauxite is subjected to high temperatures in an electric arc furnace.
Cooling and Crushing: The resulting melt is then cooled and pulverized into various sizes depending on the end use.
Characteristics of fused corundum
The superior performance of fused alumina in ceramic applications can be attributed to its unique properties:
1. Extremely high hardness: The hardness of fused corundum is second only to diamond. This hardness makes it the material of choice for abrasive ceramics where high wear resistance is required.
2. Excellent thermal stability: Fused alumina can withstand very high temperatures without losing its structure or strength. This thermal stability makes it ideal for refractory applications where the material is subjected to extreme heat.
3. Chemical inertness: Fused corundum does not react with most chemicals. This inertness is particularly important in applications where the material comes into contact with corrosive substances.
Application of fused corundum in ceramics
The unique properties of fused alumina make it the material of choice for a variety of ceramic applications:
1. Abrasive Ceramics: Fused corundum is ideal for abrasive applications due to its hardness. In this sector it is used in the production of grinding and cutting wheels. Made from fused aluminum oxide particles, these tools can cut and grind even the hardest materials. In addition, fused aluminum oxide is used as a blasting medium for surface preparation, providing a balance between aggressiveness and precision.
2. Refractory materials: The high temperature resistance of fused corundum makes it an excellent material for refractory applications. It is used in the manufacture of refractory bricks and monolithic refractory materials for lining furnaces, kilns and reactors in various industries. These refractory materials can withstand the extreme temperatures found inside these units without degrading.
3. Ceramic proppant: In the oil and gas industry, fused alumina is used to make ceramic proppant. These are small spherical particles that are pumped into oil and gas wells during the hydraulic fracturing (fracking) process. Proppants keep fractures open, allowing oil and gas to flow more freely.
4. Technical ceramics: Fused alumina can be used in various forms of technical ceramics. These include wear-resistant parts for machinery, high-temperature ceramics for furnace applications, and electrical insulators for electronic equipment.
Fused corundum production process
To understand the value that fused alumina brings to ceramics, we need to explore its production process in more detail:
1. Raw material selection: The first step involves careful selection of high-quality bauxite. The quality of bauxite significantly affects the final properties of fused corundum. Bauxite is chosen for its rich alumina content, usually above 50%.
2. Melting in an electric arc furnace: The selected bauxite is then placed in an electric arc furnace, subjecting it to temperatures above 2000°C. The high heat ensures that the bauxite is completely melted, forming a liquid substance.
3. Cooling: The liquid material is slowly cooled to form large molten alumina crystals.
4. Crushing and grading: The cooled material is crushed and graded into different sizes. The classification process involves screening the pulverized fused alumina into various particle sizes from coarse to fine powder.
Future Prospects and Trends
The future of fused alumina in the ceramic field is bright. As the industry continues to innovate, demand for high-performance materials such as fused alumina is expected to grow. For example, the development of more energy-efficient refractories and high-performance abrasives may increase the use of fused alumina. Additionally, the trend toward more sustainable and environmentally friendly practices may also impact the production and use of fused alumina, prompting the industry to explore more sustainable sources of bauxite and energy-efficient production methods.
Economic impact
The production and application of fused corundum are of considerable economic significance. It makes an important contribution to the ceramics industry, driving growth and innovation. Additionally, it supports several other industries including the automotive, oil and gas, and electronics industries through its various applications. The economic impact of fused alumina extends beyond immediate applications, as its production involves an extensive supply chain, including bauxite mining, energy supply and equipment manufacturing.
