High Purity White Alumina Oxide Micron Powder with Overflowing Classification JIS Fepa

• Artificial Abrasive Type: Corundum Abrasives
• Application: Polishing, Grinding Wheel
• Function: Surface Finish
• Shipping Cost: Estimated freight per unit.: about shipping cost and estimated delivery time.
• Currency: US$
• Return&refunds: You can apply for a refund up to 30 days after receipt of the products.
• Model NO.: JIS240 to JIS4000
• Source: Artificial Abrasives
• Particle Size: Abrasive
• Hardness: Conventional Abrasive
• Al2O3: 99.2%
• Color: Brilliant White
• Mohs Hardness: 9
• Bulk Density: 1.5~1.95 G/Cm³
• True Specific Gravity: ≥3.9 G/Cm³
• JIS: JIS240 to JIS3000
• Fepa: F230 to F2500
• Transport Package: 25kg PP Bags Into Big, 25kg Paper Bags on Pallet.
• Specification: F8 to F220, F240 to F2000
• Trademark: Becens
• Origin: China
• HS Code: 2818109000
• Production Capacity: 1000mt/Year
• Package Size: 1.00cm * 1.00cm * 0.70cm
• Package Gross Weight: 1000.000kg
• Lead Time: 20 days (1 - 100 Tons) ; To be negotiated ( > 100 Tons)

Product Description

White Alumina Oxide also called White Aluminum Oxide, White Fused Alumina, White Corundum. 
White alumina oxide is made from industrial alumina powder, arc smelted at a high temperature of more than 2000 degrees, and then cooled. After crushing and forming, magnetic separation and iron removal, and screening into various sizes.

High-quality white alumina oxide depends on the quality of alumina powder, and the quality of alumina powder depends on the content of alumina and sodium chloride in it. When making white alumina oxide abrasives, the alumina content must be controlled above 98.4%. The content of sodium oxide is not higher than 0.6%, otherwise many substandard products will be produced, so the content of sodium oxide should be strictly controlled. High sodium oxide content will generate a lot of β-alumina, which will affect the properties of white alumina oxide, such as the decrease of crystal hardness of white alumina oxide, the decrease of cutting ability, easy pulverization and broken, low thermal stability and so on.

White alumina oxide is made of aluminum oxide powder which is melted in an electric arc furnace and then cooled and crystallized. Like brown alumina oxide, the smelting time determines whether the charge is fully melted and the carbon is fully volatilized. There is no reduction process in the smelting of white alumina oxide, so the impurities may remain in the crystal structure, which will affect the chemical composition and color of white alumina oxide and reduce the quality of white alumina oxide.

It is widly used to produce abrasive tools, both bonded abrasives and coated abrasives, like grind wheel, cutting wheel, abrasive sandpaper...;  surface treatment, like polishing and sandblasting; precision casting (corundum for precision casting) of ceramic and resin-bonded abrasive tools, and can also be used to manufacture advanced refractory materials, shaped refractory and unshaped refractory, like ramming mass, refractory brick...

Due to the fine particles of micron powder, it is extremely difficult to classify by screening method, and hydraulic classification is commonly used. Commonly used hydraulic classification methods include sedimentation method, overflow method and cyclone method.
Settlement method and overflow method are two commonly used classification methods. The principle is that the sedimentation speed of particles with the same specific gravity in water is different due to different particle sizes. Large particles settle quickly, while small particles settle slowly, so particle size classification is carried out.
When micro powder is classified in water conservancy, a certain amount of dispersant needs to be added to the slurry to disperse the micro powder particles and prevent them from coalescing.
The influence of temperature on the speed of settling micronized abrasive particles is negligible. In addition, there are many factors that affect the settling speed of abrasive particles, such as particle shape, suspension concentration, collision between particles, etc.

The cyclone hydraulic classification is to input the slurry of a certain concentration into the cone in the tangential direction. The high-speed rotation generates centrifugal force, which throws the fixed particles towards the wall of the container. Since the size of the centrifugal force is related to the size of the swirling flow, the centrifugal force of coarse particles is greater, and the centrifugal force at the center of the swirling flow is greater. Therefore, the finer particles reach a balance between the centrifugal force and the kinetic energy centripetal force near the center, while the coarser particles reach a balance near the center. The wall position reaches equilibrium.
The advantage of this method is that it does not require a dispersant, the centrifugal force of the cyclone can disperse the aggregated particles, and the sorted slurry disperses quickly. The equipment has a simple structure, high production efficiency, and a small footprint. However, the accuracy is not stable enough and the particle size changes greatly. It is difficult to adapt to narrow-level sorting. It is mostly used for the grouping of fine powders.
The concentration of the slurry will affect the accuracy of the classification particle size, so the concentration of the slurry must be adjusted before cyclone classification.

Air flow classification
There are three main forms of airflow classification: gravity, inertial force, and centrifugal force. Classification using centrifugal force fields is the most common form.
The main factors that affect air flow classification are air inlet volume, classification wheel speed, and feed rate.

Air intake volume: Its size affects the particle size distribution of graded products. For coarser principles, using a larger air volume is beneficial to dispersion and classification, while a smaller air inlet volume is beneficial to sorting fine powder, avoiding the possibility of bringing large particles into fine particles.
Speed of the classifying wheel: Adjusting the speed of the classifying wheel can change the particle size composition of the discharged material to achieve the purpose of separating products of different particle sizes. When the rotation speed is high, the separated micro powder has fine particle size, otherwise it has coarse particle size.
Feed rate: affects the efficiency of the classifier. For coarse-grained sorting, the feed rate will be larger, while for fine-grained ones, the speed needs to be reduced to avoid entering coarse materials.
In actual production, many factors that affect air flow classification affect each other, and the adjustment plan needs to be continuously explored and summarized in practice.

Micro powder drying
Drying is a process in which materials gain energy and liquid is vaporized and discharged. During drying, it is necessary to prevent the mixing of various particle sizes. Use fine particle size in the upper layer and coarse particle size in the lower layer. Drying temperature is 80-250ºC.
The characteristics of using convection hot air drying are that the equipment is relatively simple and the energy price is cheap. The disadvantages are that the heat consumption is large, the equipment is large, and it is difficult to automate. The characteristics of electric drying are exactly opposite to those of hot air drying.
 

Typical testing value (F100):


Standard sizes:
F12 to F220; 
P12 to P220; 
JIS240 to JIS4000; 
0-1mm, 1-3mm, 3-5mm, -100mesh, -200mesh, -325mesh.
In according with GB, FEPA, JIS, ANSI sieve standards. 
 

Package:
Our packages are ensured strong and safe. We could print marks as your requests, neutral marks, customers logo, no made in China etc.
1000kg and 1250kg bulk bags
40×25kg PP bags into big bag
40×25kg PP bags on pallet
40×25kg paper bags on pallet
50kg paper drums on pallet