Why the higher the whiteness of alumina, the better the quality?
Alumina powder is widely used in new ceramic materials and industrial production. Good products can help improve production efficiency. Therefore, when selecting products, we must carefully control the quality to prevent quality problems during use and cause no effect.
1. The purity of alumina powder should be high, and the oxides of elements such as silicon and iron should be as low as possible. In order to ensure its purity and whiteness, the higher the purity, the higher the whiteness.
2. Strictly require the content of heavy metal elements harmful to the human body. Radiation is a very large measure.
3. The whiteness of alumina should be as high as possible. Whether it is alumina or molecular sieve, the whiteness mainly depends on the raw material. For new ceramic materials, the whiteness does not affect the mechanical properties and processing performance of the material, but the whiteness is high and gives a good feeling, and the whiteness with the same performance has more competitive advantages.
4. The lower the oil absorption, the better. The specific surface area directly determines the oil absorption, and the firing temperature determines the specific surface area. The higher the firing temperature, the smaller the specific surface area and the lower the oil absorption rate. Special industries need to use products with lower oil absorption. At this time, it is necessary to perform surface activation treatment and process it into activated alumina to meet customer requirements.
5. The fineness should be appropriate, not the finer the better, and the particle size distribution should also be determined according to needs.
Alumina can be used to strengthen and toughen plastics, rubber, ceramics, refractory materials and other products, especially to improve the compactness, smoothness, cold and heat fatigue, fracture toughness, creep resistance and wear resistance of polymer materials. The performance is particularly remarkable. Below, let’s briefly understand the properties of alumina:
1. PH=7.0, but the specific pH value can be adjusted according to customer requirements. Adjusting the pH value has no effect on the liquid.
2. Transparent, high content, no precipitation or stratification.
3. There are water-based liquids, oily liquids, alcohol, ether, ketone liquids. All are transparent and have good compatibility.
4. The far-infrared emission material with excellent performance is used in chemical fiber products and high-pressure sodium lamps as far-infrared emission and insulation materials. In addition, alumina has high resistivity and good insulation properties, which can be used in the main parts of YGA laser crystals and integrated circuit substrates.
5. Improve the compactness, smoothness, thermal fatigue, fracture toughness, creep resistance of ceramics and the wear resistance of polymer materials.
6. With high hardness and good dimensional stability, it can be widely used to strengthen and toughen various plastics, rubbers, ceramics, refractory materials and other products.
7. Improve the scratch resistance and durability of UV-curable coatings. These UV-curable coatings are widely used in areas that require high wear resistance, such as plastic floor nano-alumina XZ-L690 in white and fluffy powder state, and the crystal form is γ- Al2O3. The particle size is 20nm; the specific surface area is ≥160m2/g. Uniform particle size distribution, high purity, good dispersion, high specific surface, high temperature resistant inertness, high activity, is activated alumina; porosity; high hardness, good dimensional stability, strong surface acidity and certain The surface is basic and is widely used as new green chemical materials such as catalysts and catalyst carriers.
From the above introduction, we can see how extensive the application of alumina is. It can not only enhance toughness, but also improve finish. It is an indispensable chemical substance in industry, and its application range will gradually expand.
Corundum, whose name comes from India, is a mineralogical name. There are three main variants of the homogeneity of corundum Al2O3, namely α-Al2O3, β-Al2O3, and γ-Al2O3. The hardness of corundum is second only to diamond.
Corundum is mainly used for abrasive materials, watch and mechanical bearing materials. Ruby-based artificial crystal as a laser emitting material. Rubies and sapphires are both corundum minerals. Except for the starlight effect, only translucent-transparent and brightly colored corundum can be used as gemstones. The red color is called ruby, while the other colors of corundum are collectively called sapphire in business.
Corundum is a gemstone formed from the crystals of alumina (Al2O3). Corundum mixed with metallic chromium is bright red and is generally called ruby; while blue or colorless corundum is generally classified as sapphire.
It is formed under the conditions of high temperature rich in aluminum and poor in silicon. In the endogenous process, it is produced in magmatic rocks and pegmatites rich in aluminum and poor in silicon, and symbiosis with feldspar and spinel. In metamorphism, those produced in gneiss symbiosis with skarn, magnetite, muscovite, etc.; those produced in the contact zone of magmatic rock and limestone symbiosis with calcite, magnetite, epidote, etc. The product of magmatic rock desilication. It belongs to the trigonal crystal system, and the crystal form is often intact hexagonal columnar or barreled. Oblique stripes or horizontal stripes are often developed on the cylindrical surface. Triangular cracks are sometimes seen on the bottom surface; the aggregates are granular.
The main causes of corundum are as follows:
(1) The conditions of high temperature and high pressure formed in the mantle are ejected from the surface with magma.
(2) Formed by contact metamorphism.