White corundum is made of industrial alumina powder and smelted in an electric arc at a temperature of more than 2000 degrees. After crushing, shaping, magnetic separation and iron removal, it is screened into various particle sizes. Compact texture, high hardness and spherical particles. White corundum is suitable for manufacturing ceramics, resin binders, grinding, polishing, sand blasting, precision casting and so on. It can also be used to manufacture advanced refractories. The code name "WA" conforms to international general standards and national standards.
The product granularity is produced according to international standards and national standards, and can be processed according to the granularity required by users. Generally, the particle size number is F4~F320, and its chemical composition varies according to the particle size. Outstanding features are small crystal volume, impact resistance, mostly spherical particles, dry and clean surface, and easy to combine with binder.
White corundum density: There are two densities, one is the volume density of white corundum, and the other is the true density of white corundum.
The bulk density is 1.53~ 1.99g/cm3. The bulk density of abrasives is related to factors such as particle size, particle composition, variety and particle shape. Generally speaking, the bulk density of coarse-grained abrasives is higher than that of fine-grained abrasives, and the bulk density of mixed-particle abrasives is higher than that of single-particle abrasives.
The particle density is 3.95~4.0g/cm3, and the true density of abrasive refers to the mass of abrasive contained in unit volume (excluding the volume with pores).
tangible property
Crystal triangle system
Chemically amphoteric
It reacts with acid and slightly corrodes in aqua regia and hydrofluoric acid.
Reaction with alkali only slightly reacts with strong alkali hot solution.
Redox effect no
The density is 3.90g/cm3.
difficulty
Knoop hardness is 2000-2200 kg/mm2.
Mohs hardness 9.0
The color is white.
The color after calcination is dark blue.
The melting point is 2250 degrees Celsius.
The maximum operating temperature is1900 C.
Specific heat (calories/degrees Celsius) 0.26 (20-90 degrees Celsius)
Thermal conductivity at room temperature of 900°C
(calories per cubic centimeter. Second c)
The refractive index e =1.760w =1.768 (naline).
The resistivity is 30 c 300 c 900 c1600 c (cm).
10 16 10 13 10 5 10 4
Linear expansion coefficient (7-9) *10-6/k (0-1600c)
2:
Brown corundum
Commonly known as emery, it is brown artificial corundum made by melting and reducing bauxite, carbon materials and iron filings in an electric furnace, so it is called brown corundum. The main chemical composition of brown corundum is AL2O brown corundum 3, with a content of 94.5%-97%, and a small amount of Fe, Si, Ti, etc.
Brown corundum is made of high-quality bauxite, anthracite and iron filings, which are smelted at a high temperature above 2000 degrees in an electric arc. It is crushed and shaped by a autogenous mill, and iron is removed by magnetic separation and screened into various particle sizes. Its texture is compact, its hardness is high, and its particles are spherical. Suitable for manufacturing ceramics, resin high consolidation abrasives, grinding, polishing, sandblasting, precision casting, etc. It can also be used to manufacture advanced refractories.
Brown corundum has the characteristics of high purity, good crystallization, strong fluidity, low linear expansion coefficient and corrosion resistance. The practice of dozens of refractory manufacturers has proved that the product has the characteristics of no explosion, no pulverization and no cracking in the application process. In particular, its cost performance is much higher than that of traditional brown corundum, and it is the best aggregate and filler for brown corundum refractories.
The product granularity is produced according to international standards and national standards, and can be processed according to the granularity required by users. Generally, the particle size number is F4~F320, and its chemical composition varies according to the particle size. The outstanding characteristics are small grain size and impact resistance. Most of the particles are spherical because they are crushed by a self-grinding machine. Sharp brand brown corundum has the characteristics of high purity, dense texture, high bulk density, strong self-sharpening, good toughness and extremely low magnetic content. The abrasive tool made of it has the advantages of sharp grinding, low heating speed, high grinding ratio and less adhesion when used. Sintered abrasives have the characteristics of dark blue after firing, no net cracks and no rust spots, and are suitable for manufacturing ceramic and resin high consolidation abrasives, grinding and polishing.
Brown corundum is one of the most basic abrasives with high hardness and good toughness.
Its main functions are as follows
(1) Because of its high temperature resistance, corrosion resistance and high strength, slide gate is used to refine the lining (walls and pipes) of rare and precious metals, special alloys, ceramics and ironmaking blast furnaces. Physical and chemical ware, spark plug, heat-resistant and oxidation-resistant coating.
(2) Because of its high hardness, good wear resistance and high strength, it is used as a component of various reaction vessels, pipelines and chemical pumps in the chemical system; Making mechanical parts, various dies, such as wire drawing die, extruding pencil lead die, etc. Making tools, mold abrasives, bulletproof materials, human joints, sealing mold rings, etc.
(3) corundum thermal insulation materials, such as corundum lightweight bricks, corundum hollow balls, fiber products, etc., are widely used in the furnace walls and tops of various high-temperature furnaces, which are both heat-resistant and heat-insulating. Brown corundum particle size sand is made by manually selecting brown corundum blocks and processing them with roller pair, ball milling and Bamak equipment. The particle size is F8 F325. It is mainly used for polishing, grinding and industrial grinding, and can also be processed by washing and pickling according to customer requirements, which can meet different requirements of customers.
After pre-treatment and special process, the low-carbon brown corundum reduces the residual carbon content in brown corundum, making the product not powdery, explosive and tough in use. It is the preferred raw material for abrasive and abrasive industry and refractory industry. Mainly used in ceramic abrasives, high-grade abrasives, organic abrasives, abrasive belts, coated abrasives and so on.
According to the carbon residue, it can be divided into calcined brown corundum C ≤0.05%, low-carbon brown corundum C ≤0. 10% and ordinary brown corundum C ≤0. 15%.