Calcined alumina is a type of aluminum oxide that has been heated to a high temperature, causing it to become more crystalline and harder. This makes it an excellent abrasive material for polishing, as it can remove material quickly and evenly without leaving scratches.
Calcined alumina applications
Calcined alumina is used in a variety of polishing applications, including:
- Glass polishing: Calcined alumina is used to polish glass to a high degree of clarity and smoothness. It is also used to remove scratches and blemishes from glass.
- Metal polishing: Calcined alumina is used to polish metals to a mirror finish. It is also used to remove rust, oxidation, and other surface contaminants from metals.
- Jewelry polishing: Calcined alumina is used to polish jewelry to a high shine. It is also used to remove scratches and blemishes from jewelry.
- Optical polishing: Calcined alumina is used to polish optical components, such as lenses and prisms, to a high degree of precision. It is also used to remove surface defects from optical components.
- Semiconductor polishing: Calcined alumina is used to polish semiconductor wafers to a high degree of smoothness. This is necessary to ensure that the wafers are free of defects and that they can be properly etched and implanted with dopants.
Calcined alumina is available in a variety of particle sizes, from coarse to fine. The particle size that is used will depend on the specific application. For example, coarse calcined alumina would be used for initial rough polishing, while fine calcined alumina would be used for final polishing.
Advantages of Calcined Alumina for Polishing
Calcined alumina is a versatile and effective abrasive material for polishing. It is used in a wide variety of applications, from glass polishing to semiconductor polishing. When used properly, it can produce a high-quality finish on a variety of materials.
Here are some additional benefits of using calcined alumina for polishing:
- It is inert and non-toxic, making it safe to use on a variety of materials.
- It is very hard and durable, so it can withstand repeated use without becoming dull.
- It is available in a variety of particle sizes, so it can be used for a variety of polishing applications.
- It is relatively inexpensive, making it a cost-effective option for polishing.
How Calcined Alumina is Produced
Calcined alumina is produced through a series of intricate processes that transform the raw bauxite ore into a refined and valuable material.
Extraction of Alumina from Bauxite
The Bayer’s process is the most common method used to extract alumina from bauxite. Here’s how it works:
- Crushing and Grinding: The bauxite ore is first crushed and ground into a fine powder.
- Digestion: The powdered bauxite is mixed with a strong alkali, usually sodium hydroxide, and heated under pressure. This dissolves the aluminum hydroxides in the ore.
- Clarification: The liquid containing dissolved alumina is separated from the insoluble residues.
- Precipitation: Aluminum hydroxide is precipitated from the solution by cooling and seeding with fine alumina particles.
- Calcination: The precipitated aluminum hydroxide is heated to high temperatures (usually above 1100°C) to remove water and other volatile substances, leaving behind pure alumina.
Some alternative methods to the Bayer’s process include the sinter process and the combined Bayer-sinter process. These methods may be used depending on the type of bauxite ore and the desired properties of the calcined alumina.
Milling and Grading
After calcination, the alumina is milled into the desired particle size and graded according to its intended application. Different grades of calcined alumina are produced to cater to various industrial needs, including polishing.
Calcined Alumina Supplier – Henan Superior Abrasives
Henan Superior Abrasives is a prominent name in the world of abrasives and is known for its high-quality silicon carbide and calcined alumina. We have carved a niche for itself by providing top-notch products that cater to various industrial needs, including polishing.
Overview of Henan Superior Abrasives
Located in Henan, China, Henan Superior Abrasives specializes in the production and supply of abrasive materials, including calcined alumina, silicon carbide. such as Black Silicon Carbide, available as Macro Grits and Micro Powder, and Green Silicon Carbide, also available as Macro Grits and Micro Powder. With a commitment to quality and innovation, we have become a trusted name in the industry.
Products and Grades
Henan Superior Abrasives offers various grades of calcined alumina, each tailored to specific applications. These include:
- Polishing Grade: Specially designed for polishing metals, glass, ceramics, and other materials.
- Refractory Grade: Used in the production of refractory materials.
- Ceramic Grade: Suitable for ceramic applications.
Quality is at the core of Henan Superior Abrasives’ operations. The company adheres to stringent quality control measures to ensure that the calcined alumina meets international standards. This includes:
- Regular testing for purity, hardness, and particle size.
- Compliance with industry certifications and regulations.
- Collaboration with research institutions for continuous improvement.
Henan Superior Abrasives recognizes the importance of environmental stewardship and implements sustainable practices in its operations. This includes:
- Efficient use of resources.
- Waste reduction and recycling.
- Compliance with environmental regulations.
If you have any needs for silicon carbide, calcined alumina or other abrasives, please feel free to contact us!