A vigorous company, Yiyuande mineral Co., Ltd. Plays an active role in the supply of minerals, refractory materials and abrasives from China to Japan, Spain, Australia, USA, Turkey. Iran, Korea and other destinations.
| Product |
Chemical composition (%) &Physical properties |
| AL2O3 |
FE2O3 |
SIO2 |
P.D (G/CM3) |
| 99.65% |
≤0.01% |
0.11% |
0.5-1.0 |
| Note |
We Can Produce According To The Customer's Special Demand Or Sizes |
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Product Parameters
On the market, there are many manufacturers of alumina hollow,how to select a good hollow for their own alumina? Alumina hollow are lightweight Refractory that are heat-resistant and energy-efficient, and are commonly used in high-temperature furnaces as ultra-high-temperature insulation fillers. For this purpose, we need to refer to the alumina hollow of sodium oxide content, sodium oxide content is too high, easy to cause kiln collapse phenomenon. Our company has strict requirements for the purchase of raw materials. We only use the products of the large domestic alumina group, and use batch inspection for the storage of raw materials, thus at the source of control of sodium oxide, the problem of excessive content. Alumina hollow is used in the production of alumina hollow ball brick, in addition to the sodium oxide content concern, but also should choose the ball wall thickness, appropriate products. Alumina hollow wall is too thick, not conducive to thermal insulation, but also increased the cost of manufacturers, but the wall is too thin, its bearing capacity will be affected. So we require both for the good, that is, both its support, but also save the cost of manufacturers. Alumina hollow to do ordinary castable use, according to the environmental temperature you need, reasonable choice.
The formation process of hollow is completed in 10 ~ 30 seconds by high pressure air injection of molten alumina. The pelletizing process is actually a rapid cooling and shrinking process. The melting point of alumina is 2050 ° C, suitable, the blowing temperature should be higher than the melting point of 200 ~ 300 ° C, that is, heating to 2200 ~ 2300 ° C. If the melt, the temperature is low, viscosity is large, it is easy to blow into a thick wall or honeycomb hollow ball. There are three stages in blowing alumina hollow spheres: the first is melting, increasing temperature and reducing melt viscosity, the second is blowing, and the third is cooling and curing.
The formation of alumina hollow sphere is a process of volume shrinkage of high temperature molten alumina after injection and rapid cooling. This is the process by which molten aluminum oxide is blown away into a myriad of tiny droplets by high-pressure air. These droplets fall in the air in a parabolic trajectory. In this process, under the action of surface tension and centrifugal force, the small drop first forms a small sphere when the small sphere is suddenly cooled, the surface is instantaneously solidified, but the interior of the sphere is still in a liquid state, under the action of centrifugal force, at the same time, the melt produces a large volume contraction, which makes the melt solidify on the shell of hollow sphere quickly and evenly, thus completing the whole process of forming hollow sphere.
The internal shrinkage of the hollow sphere comes from the volume expansion of the alumina during the heating process. Although AL2O3 has only 1.6% ~ 1.8% linear expansion when heated to 1800 ° C, when the oxide is heated to the melting point and temperature, when the substance changes from solid phase to liquid phase, there will be 20% ~ 40% volume expansion. This volume expansion is related to the chemical bonds of the molecules. The larger the component of chemical bond such as ionic bond, the larger the volume difference between the liquid and the solid, whereas the larger the component of covalent bond, the smaller the volume difference. When alumina is changed from solid phase to liquid phase, its molar volume expands by about 23.5% . Therefore, hot expansion and cold contraction, is the fundamental cause of the formation of alumina hollow ball. The temperature of molten alumina fluctuates from 2200 ° C to 2300 ° C when blowing alumina hollow balls.
The high temperature liquid state of alumina has a greater thermal expansion rate. The linear expansion coefficient of a high temperature liquid is generally 3 times that of a solid. The high temperature liquid contains some gas partial pressure, which accelerates the expansion of high temperature liquid and is an important factor to promote the formation of alumina hollow sphere.
Packaging & Shipping
EXHIBITION
Answer Your Concerns
Q1: Could I get a sample before placing an order?
A: Yes. A sample as per your requirement can be prepared for approval.
Q2: How can I get an offer?
A: Contact our expert or send us your requriement and quantity.
Q3: What's the Min. Order Quantity (MOQ)?
A: There is no MOQ for regular size. But customized size MOQ: 20MT
Q4: Do you have stocks?
A: Yes, but only for regular size.
Q5: Can I use my marking information on the bags?
A: No Problem.
Q6: How do you deliver my orders?
A: Our experts can recommend you the suitable way based on the quantity and your budget. Normally ,it is by sea.
Q7: I am a big buyer, can I get a competitive price?
A: Yes, you will get our lowest price without quality compromise along with our professional service.As we are working with mainly players in Europe, Asia, America and Afraic.
Q8: What is your quality control?
A: 1.Chemical inspection is performed during Raw material, production and finished products.
2.Physical test is performed for finished products.
Q9: Are you a manufacturer?
Yes, we have 20 years production experience .
Once you are interested in the bauxite, feel free to contact us - a reliable supplier YIYUANDE !
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