Calcined alumina is a product obtained by calcining aluminum hydroxide at high temperature to partially or almost completely convert it into aAl2O2.
Calcined alumina powder for refractory material
Calcined alumina powder is a product obtained by calcining aluminum hydroxide at high temperature to partially or almost completely convert it into aAl2O2. Calcined alumina can be classified into many grades according to calcination (crystal size, specific surface area) and Na2O content (0.01%~0.5%). The so-called industrial alumina (or industrial alumina) in our country is a kind of calcined alumina, but its general calcination degree is poor.
The production methods of calcined alumina mainly include Bayer method, soda lime sintering method, and Bayer-sintering combined method.
The smaller the particle size of a-alumina micropowder, the higher the activity, the better the dispersibility, and the better the water reducing effect and dispersibility in the castable. In the case of the same ratio and the same amount of addition, the addition of alumina fine powder with small particle size improves the construction performance of the castable, the bulk density is large, and the flexural strength and compressive strength at room temperature and high temperature are higher than those with large particle size. Alumina micropowder castable. For the alumina powder with large particle size, the fluidity of the castable decays faster, and the working time of the castable becomes shorter.
The greater the amount of alumina powder added, the better the fluidity of the castable. This is because the alumina micropowder has a small particle size and can be filled into the gaps and flocculation structures between particles.
The higher the amount of alumina added, the higher the high temperature cold flexural strength of the castable, because a large number of staggered CA2 and CA6 crystals are formed in the matrix, forming a network-like structure in the matrix.
|
type |
Project |
Al2O3% |
SiO2% |
Fe2O3% |
Na2O3% |
burn |
true density(g/cm3) |
α-Al2O3 |
|
low sodium |
AN-03 |
99.5 |
0.06 |
0.03 |
0.03 |
0.10 |
3.97 |
95 |
|
AN-05 |
99.5 |
0.06 |
0.03 |
0.05 |
0.10 |
3.97 |
95 |
|
|
AN-10 |
99.3 |
0.08 |
0.04 |
0.10 |
0.10 |
3.96 |
95 |
|
|
AN-20 |
99.0 |
0.10 |
0.05 |
0.20 |
0.20 |
3.95 |
93 |
|
|
medium sodium |
AN-30 |
99.5 |
0.04 |
0.04 |
0.30 |
0.20 |
3.93 |
90 |
|
AN-40 |
99.0 |
0.10 |
0.05 |
0.40 |
0.20 |
3.90 |
85 |
|
|
AN-50 |
97.0 |
0.15 |
0.10 |
0.50 |
0.40 |
3.85 |
80 |
Advantages of a-alumina powder:
smaller particle size
higher activity
better dispersion
The better the water-reducing effect and dispersibility in the castable
The high-alumina refractory bricks sold by Yuying refractory manufacturers are commonly used refractory bricks with high thermal stability and refractoriness above 1770°C. It has good slag resistance and is used for the lining of steelmaking electric furnaces, glass melting furnaces, cement rotary furnaces, etc.
High alumina castable is a refractory castable made of high alumina bauxite clinker as aggregate and refractory clay as powder, adding aluminate cement and sodium tripolyphosphate according to the formula proportion
In the blast furnace smelting process, blast furnace taphole clay, as a key plastic material, plays a vital role. This article will introduce in detail the product characteristics, working principle and innovation of blast furnace taphole clay in improving furnace stability and production efficiency.
High alumina brick is one of the indispensable basic refractory materials in the upper and middle parts of blast furnace body in iron and steel industry
Common low-creep high-alumina bricks can be used in blast furnace hot blast stoves, as well as other industrial kilns, and can also be made into low-creep high-alumina bricks of different sizes according to specific construction requirements, such as lattice bricks, special-shaped bricks, anchor bricks, etc. , mainly used in industrial kilns in long-term high temperature environments
Fireclay bricksis suitable for supporting hot blast stoves of large, medium and small blast furnaces
Insulating high alumina refractory bricks mainly refer to refractory products with an aluminum content of more than 48%. They are also called lightweight high-alumina bricks or heat-insulating high-alumina bricks due to their advantages of low bulk density, light weight, and good heat insulation effect. . It is a kind of thermal insulation refractory brick commonly used in high temperature industrial kilns and thermal equipment.
Anhydrous taphole mud/taphole clay refers to taphole mud made of tar, resin, etc. as binders and corundum, bauxite, clay, silicon carbide, coke powder, etc. as raw materials. Anhydrous carbon taphole mud is made by a mud mill. When rolling, oil is added first, then block materials (clay and asphalt), and then powder materials (coke powder and clinker powder) are added after crushing. After pressing and mixing, the mud can be produced when it meets the standards.

