In the field of abrasives and refractory materials, fused alumina stands out as a crucial material with wide - ranging applications. Among the various types of fused alumina, white fused alumina and brown fused alumina are two of the most commonly used. As a supplier of white fused alumina, I am well - versed in the characteristics of both products and am eager to share the differences between them.
1. Chemical Composition
The chemical composition is the fundamental factor that differentiates white fused alumina from brown fused alumina.
Brown fused alumina is mainly produced from bauxite, iron filings, and anthracite through an electric arc furnace smelting process. It typically contains about 94.5% - 97% aluminum oxide ($Al_2O_3$), along with small amounts of silicon dioxide ($SiO_2$), titanium dioxide ($TiO_2$), and iron oxide ($Fe_2O_3$). The presence of these impurities gives brown fused alumina its characteristic brown color.
On the other hand, white fused alumina is made from high - purity alumina powder. It has a much higher aluminum oxide content, usually above 99%. The extremely low impurity levels, especially in terms of $SiO_2$, $TiO_2$, and $Fe_2O_3$, contribute to its white color. This high - purity composition makes white fused alumina have unique properties that are different from brown fused alumina.
2. Physical Properties
Hardness
Hardness is a key physical property for abrasive materials. Brown fused alumina has a Mohs hardness of about 9, which is relatively high and suitable for many general - purpose abrasive applications. It can effectively grind and polish a variety of materials, including metals, ceramics, and glass.
White fused alumina has a slightly higher hardness, close to 9.2 on the Mohs scale. This extra hardness makes it more suitable for applications where a finer and more precise grinding is required. For example, in the manufacturing of precision tools and high - end electronic components, white fused alumina can provide a smoother and more accurate surface finish.
Grain Shape
The grain shape also varies between the two. Brown fused alumina grains usually have a more irregular and angular shape. This irregularity gives it good cutting ability during the grinding process, as the sharp edges can easily penetrate the material being ground.
White fused alumina grains tend to be more blocky and have a more regular shape. This regular shape results in a more consistent grinding performance, reducing the risk of surface damage and providing a more uniform finish.
Specific Gravity
The specific gravity of brown fused alumina is around 3.9 - 4.0 g/cm³. This relatively high specific gravity allows it to have good sedimentation properties in some applications, such as in abrasive slurries.
White fused alumina has a specific gravity of approximately 3.95 - 4.05 g/cm³. The slightly higher specific gravity can also be an advantage in certain applications, such as in the production of high - density refractory materials.
3. Manufacturing Process
The manufacturing processes of white fused alumina and brown fused alumina are quite different.
Brown fused alumina is produced by smelting bauxite, iron filings, and anthracite in an electric arc furnace at a high temperature of around 2000 - 2200°C. During the smelting process, the impurities in the bauxite are reduced and removed, and the aluminum oxide is melted and recrystallized to form the final product. This process is relatively simple and cost - effective, which is why brown fused alumina is more widely used in general - purpose applications.
White fused alumina is manufactured by melting high - purity alumina powder in an electric arc furnace at a temperature of about 2050 - 2250°C. The high - purity raw material and the strict control of the melting process ensure the high quality and purity of the final product. However, this process is more complex and requires more energy, resulting in a higher production cost compared to brown fused alumina.
4. Applications
Abrasive Applications
Brown fused alumina is widely used in general - purpose abrasive applications. It is commonly used in grinding wheels for grinding metals, such as steel, cast iron, and non - ferrous metals. It is also used in sandblasting operations to clean and prepare metal surfaces for painting or coating. In addition, brown fused alumina is used in abrasive papers and belts for woodworking and metalworking.
White fused alumina, due to its high purity and hardness, is mainly used in high - precision abrasive applications. It is used in the manufacturing of grinding wheels for grinding hard and brittle materials, such as ceramics, carbides, and optical glass. It is also used in the production of super - fine abrasive powders for polishing high - end electronic components, such as semiconductor wafers and LCD screens. You can find more information about White Aluminum Oxide Abrasive Media.
Refractory Applications
In the refractory industry, brown fused alumina is used to produce refractory bricks, castables, and other refractory materials for use in high - temperature environments, such as in steelmaking furnaces, cement kilns, and glass melting furnaces. Its relatively low cost and good thermal stability make it a popular choice for these applications.
White fused alumina is used in high - performance refractory materials. It can improve the refractoriness, thermal shock resistance, and chemical stability of the refractory products. These high - performance refractory materials are used in ultra - high - temperature applications, such as in aerospace engines and high - temperature experimental furnaces.
5. Price
The price difference between white fused alumina and brown fused alumina is significant. Brown fused alumina is more cost - effective due to its relatively simple manufacturing process and lower - cost raw materials. It is widely available in the market at a lower price, making it suitable for large - scale and general - purpose applications.
White fused alumina, on the other hand, is more expensive. The high - purity raw materials and the complex manufacturing process contribute to its higher price. However, for applications that require high - precision and high - performance materials, the cost is often justified by the superior quality and performance. If you are interested in White Fused Alumina Price, you can visit the link for more details.
6. Conclusion
In summary, white fused alumina and brown fused alumina have distinct differences in chemical composition, physical properties, manufacturing process, applications, and price. Brown fused alumina is a cost - effective option for general - purpose abrasive and refractory applications, while white fused alumina is the preferred choice for high - precision and high - performance applications.
As a supplier of White Fused Aluminium Oxide, I understand the unique requirements of different customers. Whether you need a large quantity of brown fused alumina for general - purpose use or high - quality white fused alumina for specialized applications, I can provide you with the most suitable products. If you are interested in purchasing our products, please feel free to contact me for further negotiation. I am looking forward to establishing a long - term and mutually beneficial cooperation with you.
References
- "Abrasive Materials Handbook", published by ABC Publishing House.
- "Refractory Materials Science and Technology", written by XYZ Research Group.
