The development of low creep high alumina brick

 Low creep high alumina brick is an acquainted product for refractory material and steel making workers. In 1985,in order to realize the nationalization of refractory material for Baosteel second-stage construction, metallurgy organization pay more attention to the research the low creep high alumina brick reaching the Japanese level.

Until now, many factories can produce the higher quality low creep alumina brick for the blast furnace and cowper stove. The burdening of the most of homebred low creep alumina brick is to add the family of sillimanite materials, whose process is complicated and cost is higher.

Early guidance Tangshan Iron and Steel author refractory plant for Bao steel to develop low creep high alumina brick, but with pure silica powder as a secondary mullitization provenance, products in 1550 ℃ 0.2 MPa 50 h creep rate index level over Japan. There was no disclosure of the technical know how to add quartz. In fact, this is a lesson to be learned from an article in the Russian data. A Ukrainian Institute refractory low creep high alumina brick submitted on paper entitled. High alumina refractories with high creep resistance at temperatures. At first glance, the title seems to be no novelty, but its high-performance products. The technology index of industrial scale produced by this share company :w(Al2O3)>73%, show porosity ≥18%,compression strength >100Pa, Heavy softening temperature (0.5MPa)> 1750 ℃, the creep rate (1600 ℃ 1.5MPa24h) <0.09%.Here note load softening temperature and pressure values creep rate tests.

Low creep high alumina brick is generally cannot afford such high stresses. The products used in the lower temperature hot stove brick dome, more than 9.5 years of continued operations. Speaker did not introduce technical points, did not explain the materials used, but no mention of the addition of quartz. But between the lines describe a little trace impurities in the raw material properties, the industry can determine its so-called "purity of 99% SiO2" is quartz, quartzite and general purity. In fact, the use of fused alumina, activated alumina, and a quartz-based raw materials to manufacture non-uniform state technical essentials multiphase quartz reaction product is so fully realized mullite bonded corundum microstructure to achieve excellent high temperature performance.

Article Source: The development of low creep high alumina brick
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Refractory bricks used for different parts of blast furnace

 Blast furnace is the main equipment for ironmaking, and clay brick is the earliest furnace lining material used in blast furnace. Blast furnace has the advantages of large output, high productivity and low cost, which is unmatched by other ironmaking methods.

The refractory materials and refractory bricks used in diffreent parts of blast furnace are as follows.

(1) Furnace hearth
One of the main functions of furnace hearth is to hold molten iron safely. The hearth refractory material must be stable enough when the temperature is highter than 1500 ℃. So for furnace hearth bottom, we need to choose carbon brick which has the advantages of anti-molten iron penetration, good melting, alkali resistance erosion, good thermal conductivity. And we can use small carbon brick to take the place of large carbon block, or construct ceramic rings on the carbon bricks.

(2)Tuyere zone and bosh
Temperature in tuyere area and furnace bosh is the highest in the blast furnace. The hot gas temperature produced in front of the tuyere rises at a high speed, the temperature can reach 1600 ℃ and higher. When 1450 ~ 1550 ℃molten iron and slag flow furnace hearth and finally flow to the furnace bosh, there will be a variety of metallurgical reactions happen in this area violently. Those two areas need refractory materials with characteristics of good resistance to high temperature and slag erosion, good alkali resistance, anti carbon dioxide and anti water oxidation. China refractory bricks we can use in this area are corundum brick, alumina carbon brick, hot pressed semi-graphite carbon brick, SiC brick and so on.

(3)Furnace bosh and lower furnace stack
The lower furnace stack is the position of root cohesive zone where the temperature is quite high, but slag layer or stable slag layer self protection can not be formed. This are need ds refractory materials which can bear severe temperature fluctuations, and also has advantages of alkali metal erosion, zinc erosion, carbon monoxide erosion, etc. What’s more, refractory materials used in furnace bosh and lower furnace stack should have good thermal shock stability, high temperature resistance, good alkali resistance and other properties. Refractory bricks can be used in these two areas are high alumina brick, corundum brick, alumina carbon brick, SiC brick and so on.

(4)The middle and upper part of furnace stack
The furnace stack middle part’s temperature is lower than that of furnace stack lower part. People genarally use high alumina brick, corundum brick and silicon carbide in furnace stack middle part. The temperature in furnace stack upper part is relatively lower than other parts, and it mainly affected by the wear and impact of the burden, alkali metal, zinc and carbon deposition erosion. This area requires refractory material has advantages of good wear resistance, good alkali resistance and good thermal shock stability. Refractory bricks can be used in this area are clay brick, high alumina brick, sillimanite brick, corundum brick. There is a trend that cooling walls are taking the place of refractory bricks used in blast furnace.

Article Source:Refractory bricks used for different parts of blast furnace
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
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High alumina brick and alkali brick

High alumina brick
High alumina brick has high compressive strength, high refractoriness under load and good thermal shock resistance. Because of its low cost with high quality, it is widely used in varieties of cement kilns. When to be used in arch crown, calcined alumina brick is better.

High alumina bricks suitable for cement kilns include phosphate bonded alumina brick, phosphate bonded high alumina wear-resistant brick, anti-stripping alumina brick, chemically bound (special) alumina brick and general alumina brick and so on.

Alkali Brick Series
Alkali brick has excellent alkali corrosion performance, under certain conditions, it will react with the alkali compound kiln materials and kiln gas, rapidly forming enclosed type dense protective enamel layer on the turn, preventing the continuing internal mixing and bricks "base crack ", which is a indispensable kiln lining material in NSP kiln. This series bricks include ordinary alkali-resistant brick, high-strength alkali-resistant brick, insulation alkali-resistant brick and arch type alkali-resistant brick.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.
Article Source:High alumina brick and alkali brick
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
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The reason of crack mesh high alumina brick

Changxing refractory shows the reasons for the high alumina refractory bricks to produce reticular cracks. It is reported that high alumina bricks often appear on the surface of the crack is the production of high alumina brick defects, the reasons for this network cracks often quite complicated. For example, the clinker content (especially R2O content), the amount of fine powder added, the critical particle size, the mixing quality of the clay, the humidity and the temperature of the green body, the shrinkage of the green body during the firing, Mulli petrochemical reaction and corundum recrystallization, etc., will lead to the surface of the refractory product produced reticulate. The sintering of high alumina brick is liquid phase sintering, the formation temperature of liquid phase and the amount of liquid phase, the firing conditions of the atmosphere is also an important factor in the surface network cracks.
The sintering degree and firing atmosphere of high alumina bricks and the volatiles present in the gas phase have a great influence on the surface crack of high aluminum products. Sintered bad clinker in the process of burning products continue to shrink, causing the product cracking and crack; at the same time sintering bad clinker, the second Mulli Petrochemical is not sufficient, in the process of burning products, clinker itself Mullerite is still continuing, which is caused by inconsistencies in the product of an internal factor, resulting in the number of products increased the number of cracks and the increase in the degree of cracking.
High-aluminum refractory products on the surface of the degree of mesh cracking with the clinker used in the water absorption is closely related. The greater the water absorption of clinker, the greater the degree of reticulation. When the clinker with the water absorption rate, the product in the firing process clinker itself to continue to complete the sintering process, products shrink larger, and uneven, and thus prone to cracking and reticulation. In addition, the firing atmosphere of the kiln is one of the causes of the network cracks in the high aluminum products. When the high aluminum products are fired, the atmosphere of the kilns is weakly oxidized and the excess air coefficient is controlled at 1.1-1.2. The practice shows that the surface cracks Excess air coefficient increases and decreases, but the excess coefficient of air fluctuations should not be too large.
Changxing refractory are mainly producing high alumina brick, high alumina refractory bricks, alkali resistant brick, castable, clay brick, insulation brick, light high alumina brick, low creep high alumina brick, high aluminum wear Brick, high aluminum lightweight insulation brick, clay insulation brick, if you have any need please contact us anytime.
Article Source: refractory fire brick
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
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The details of high alumina brick

High alumina brick is containing Al2O3 more than 48% of aluminum silicate products. According to the different composition of minerals, high-quality refractory products are divided into corundum, mullite a just jade and silicon stone three categories. Corundum products, AI2O3 content of more than 95%, the basic mineral corundum (A12O3), raw materials for natural or artificial corundum, but also fused corundum products. The basic mineral of mullite-corundum is mullite (3A12O3.2SiO2), the rest is corundum and glass phase. Silica stone stone raw materials for the sillimanite (Al2O3 · SiO2), the basic minerals are mullite and glass phase. A large number of industrial applications are mullite and silicon wire stone high alumina brick. With the increase of Al2O3 content and the decrease of glass phase, the refractoriness and resistance to rapid cooling of the products are improved, and the resistance to slag resistance, especially for acid slag, is enhanced.
The main raw material of high alumina bricks is high bauxite, which contains minerals such as boehmite, boehmite and kaolinite. The bauxite is calcined and the minerals are converted to corundum and mullite crystals at different temperatures. And in the 1400-1500 ℃ temperature, corundum and quartz combined with the second mullite, crystal growth. In the high-aluminum clinker with soft raw clay as a binder. The production process of high alumina brick and clay brick is basically the same.

Most of the performance of high alumina brick is better than refractory fire brick, but the thermal stability is slightly lower than clay brick. With the different content of Al2O3, ordinary high alumina brick is divided into three grades: (LZ) -65, (LZ) -55, (LZ) -48.

As the main component of high alumina brick AL2O3 is an amphoteric oxide, acid and alkaline slag erosion can resist the erosion of iron oxide skin also have a certain resistance. It is often used to build the soaking furnace bottom, the lower furnace wall, the exhaust outlet at the vault, in the continuous heating furnace, the bottom of the furnace wall, burner brick, ceiling can be used high aluminum brick masonry. High aluminum bricks are also commonly used as lattice bricks, repairing thermal storage rooms.

High alumina brick in the industrial advanced countries, the proportion of total refractory materials is about 8-14%, China's high alumina bauxite rich resources for the development of high alumina brick to create favorable conditions.

Article Source: Generality High Alumina Brick
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
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Physical and chemical index of Low creep high alumina brick

Low creep high alumina brick is a special bauxite clinker as the main raw material, supplemented by special additives, high pressure molding, high temperature firing, with thermal storage capacity, small creep rate, etc., suitable for small and medium blast furnace Matching hot air stove.
Creep high alumina bricks physical and chemical indicators
Specifications DRL-135 DRL-145 DRL-150 DRL-165 DRL-155 DRL-150
Al2O3,% ≥ 70 75 80 65 55 48
Refractoriness, ℃ ≥ 1790 1790 1790 1790 1770 1750
Apparent porosity,% ≤ 20 20 19 24 24 24
Normal temperature compressive strength, MPa ≥ 65 70 80 49 44.1 39.2
The rate of change of the burner,% ≥ ± 0.1 ± 0.1 ± 0.1 + 0.1 ~ -0.4 + 0.1 ~ -0.4 + 0.1 ~ -0.4
1450 ℃ x2h 1500 ℃ x2h 1450 ℃ x2h
0.2MPa load softening start temperature, ℃ ≥ 1500 1550 1650 1500 1470 1420
High temperature creep rate,% ≤ 0.6
1350 ° C × 50 h 0.6 0.7
1450 ℃ × 50h 1500 ℃ × 50h
We are mainly producing high alumina bricks, high alumina refractory fire brick, alkali resistant bricks, refractory bricks, clay tiles, insulation bricks, light high alumina bricks, low creep high alumina brick, high aluminum wear Brick, high aluminum lightweight insulation brick, clay insulation brick, if you have any need please call our service hotline.
Chinafirebrick provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, Magnesia Carbon Brick, clay refractory bricks and other refractory.
Article Source: high alumina brick
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/