Alumina Brick

ZINFON High-Alumina Bricks

Our factory is equipped with advanced raw material screening equipment, automated forming production lines, and precision temperature-controlled firing kilns. Strict quality control is implemented throughout every stage, from raw material procurement to finished product delivery. All product performance indicators comply with national refractory material standards, making the products suitable for high-temperature operating requirements under various working conditions.

We offer customized high-alumina brick products tailored to customer requirements, meeting the masonry and maintenance needs of various kilns, furnace chambers, flues, and other equipment.

Stable product quality, a reasonable pricing system, and comprehensive pre-sales and after-sales services have earned us widespread recognition and long-term cooperation with customers both domestically and internationally.

High Alumina Brick
High alumina bricks are a type of refractory material with a primary composition of Al2O3. These bricks, which are neutral refractory materials with an alumina content of over 48%, are made from...
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Ultral High Alumina Brick
Utral high alumina bricks are high-performance refractory materials known for their high alumina content and exceptional fire resistance.

● Enhanced corrosion resistance....
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Anti-stripping High Alumina Brick
Anti-stripping high alumina bricks are manufactured using premium-grade high alumina bauxite clinker and materials containing ZrO2, which are mixed in specific proportions, formed under high...
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Phosphate Bonded High Alumina Brick
Phosphate bonded high alumina bricks are made by using phosphate as a binder to combine bauxite aggregate, and are formed by machine pressing.

● High strength with excellent...
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Sillimanite Brick
Sillimanite-based products are made by adding a certain proportion of sillimanite, andalusite, or kyanite, along with other trace elements, to the raw materials of high alumina bricks.
...
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Andalusite Brick
Andalusite high alumina bricks are made primarily from andalusite, with added bauxite, formed under high pressure, dried, and fired at 1500°C.

● High refractory properties...
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Honeycomb Ceramics
Honeycomb Ceramics are material or device designed to store and release thermal energy, widely used in energy saving technologies for industrial thermal equipment.

● Excellent...
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What is Alumina Refractory Brick

High alumina bricks are a type of fre bricks known for their exceptional heat resistance, making them crucial for various high-temperature industrial applications. These bricks are made from high-purity alumina and other raw materials. High alumina bricks tvpically have an alumina (Al203) content ranging from 48%to 90%. The higher the alumina content, the greater the refractoriness and resistance to harsh operating conditions, including thermal stress, slag, and chemical corrosion.

Benefits of Alumina Refractory Brick

High refractoriness
The refractoriness of high-alumina brick is higher than that of clay brick and semi-silica bricks, reaching 1750~1790℃, which is a high-grade refractory material. The refractoriness is mainly affected by the content, type, and quantity of Al2O3. The refractoriness increases with the increase of Al2O3 content.

Load softening temperature
Because high-aluminum products contain high levels of Al2O3, low impurities, and less fusible glass, the load softening temperature is higher than that of clay bricks. However, because the mullite crystals do not form a network structure, the load-softening temperature is still not as high as that of silica bricks.

Thermal conductivity
High alumina bricks have better thermal conductivity than clay bricks. The reason is that there is less glass with low thermal conductivity in high-aluminum products, and the number of mullite and corundum crystals with better thermal conductivity increases, which improves the thermal conductivity of the product.

Thermal shock stability
The thermal shock resistance of high alumina bricks is between clay products and siliceous products. The 850℃ water cooling cycle is only 3 to 5 times. This is mainly due to the fact that the thermal expansion of corundum is higher than that of mullite and there is no crystalline transformation. At present, the thermal shock stability of products can be improved by improving the particle structure of the product, reducing the content of fine powder, and increasing the critical particle size and particle gradation of clinker.

Slag resistance
High alumina bricks contain more Al2O3, which is close to neutral refractory materials and can resist the erosion of acidic slag and alkaline slag. Because it contains SiO2, its ability to resist alkaline slag is weaker than that of acidic slag. In addition, the slag resistance of high-aluminum products is also related to the stability of the products in the slag. Generally speaking, products with lower porosity have higher slag resistance after high-pressure molding and high-temperature firing.

Applications of Alumina Refractory Bricks in Kiln Linings

Furnace chambers
High alumina refractory bricks are indispensable for industrial furnace chambers across various industries such as metallurgy, chemical, glass, and ceramics. Their outstanding refractory performance allows them to withstand high temperatures and pressure without retreating, making them ideal for protecting furnace chambers from high-temperature erosion and corrosion. Additionally, their wear resistance ensures stable performance over extended periods, supporting the continuous operation of industrial furnaces. Furthermore, their excellent corrosion resistance in both acidic and alkaline environments ensures the integrity and safety of the furnace chambers.

Kiln chambers
High alumina refractory bricks are suitable for various kilns, such as rotary kilns, laser kilns, and graphitization kilns. Kilns operating at high temperatures require refractory bricks with high refractoriness. High alumina bricks offer high-temperature stability, wear resistance, and impact resistance, enabling long-term stable operation.

Hot blast furnace chambers
High alumina refractory bricks are suitable for the structure of hot blast furnace chambers, including combustion chambers, burners, and air ducts. Hot blast furnaces operating at high temperatures require refractory materials with high durability. High alumina bricks can work stably in high-temperature and high-pressure environments, maintaining a long service life.

Kiln linings and cladding
High alumina refractory bricks are often used as kiln linings and cladding materials to protect kiln walls from high temperatures and corrosion. The selection of kiln linings is crucial to the performance and longevity of kilns. High alumina bricks offer excellent refractory and wear-resistant properties, effectively extending the kiln's service life.

Furnace front equipment
High alumina refractory bricks can also be used in various furnace front equipment, such as the exit, tail, and burners of hot blast furnaces, as well as the combustion chambers and high-temperature flues of boilers. They provide insulation, corrosion resistance, and anti-erosion functions.

Heat treatment furnaces
In heat treatment processes, various heat treatment furnaces such as annealing furnaces, quenching furnaces, and equalizing furnaces are indispensable. These furnaces operate in high-temperature environments, requiring refractory bricks with excellent performance. High alumina refractory bricks ensure the refractory performance of furnace chambers under high-temperature conditions. They maintain stable physical and chemical properties during long-term high-temperature exposure and sudden temperature changes, ensuring the stable operation of heat treatment furnaces. Furthermore, their wear resistance and corrosion resistance ensure the integrity and smoothness of furnace chamber walls, extending the service life of heat treatment furnaces.

Electric furnace chambers
High alumina refractory bricks are widely used in various electric furnaces such as arc furnaces and induction furnaces. Electric furnaces operating at high temperatures require refractory materials with high temperature stability and electromagnetic properties. High alumina bricks can work stably in electric furnace chambers, protecting the furnace from high-temperature erosion.High alumina bricks are also used in the steel industry (blast furnaces, hot blast furnaces, electric furnaces, ladles, intermediate vessels, heating furnaces, refining furnaces, annealing furnaces, cupola furnaces), non-ferrous metal industries (smelting furnaces, refining furnaces, reflection furnaces, converters), construction materials (cement kilns, glass kilns, ceramic kilns, lime kilns, kiln cars, tunnel kilns), energy and incineration (coke ovens, circulating fluidized bed boilers, carbon roasting furnaces, incinerators), and various high-temperature industrial kilns. High alumina bricks are indispensable in industrial production with high application rates in high-temperature industrial kilns operating at 1300-1500 degrees Celsius.

Production Process of Alumina Refractory Brick

Preparazione della materia prima
Scegli l'allumina ad alta purezza (Al2O3) polvere come materia prima principale. Secondo la necessità, possono essere aggiunti alcuni materiali ausiliari, come l'argilla, sabbia di quarzo, sabbia silicea, eccetera. La selezione e il rapporto delle materie prime influenzeranno le prestazioni del prodotto finale.

Miscela di materiali
Mescolare polvere di allumina ad elevata purezza e materiali ausiliari in una certa proporzione per garantire che i vari componenti siano distribuiti uniformemente. Il processo di miscelazione può essere effettuato mediante miscelazione a secco o miscelazione a umido.

Formare
Le materie prime miste vengono modellate tramite una macchina formatrice. I metodi di stampaggio comuni includono lo stampaggio per estrusione, stampaggio a compressione, e stampaggio ad iniezione. Modellando, si possono ottenere mattoni della dimensione e della forma desiderata.

Asciutto
I mattoni sagomati devono essere asciugati per rimuovere l'umidità al loro interno. Di solito viene essiccato naturalmente o riscaldato in forno.

Sinterizzazione
I mattoni essiccati vengono messi in un forno ad alta temperatura per la sinterizzazione. La temperatura di sinterizzazione è generalmente superiore a 1500°C, e l'adobe subisce il legame delle particelle, crescita del grano, e densificazione ad alte temperature. Ciò consente alla polvere di allumina nell'adobe di subire una reazione chimica per formare una fase minerale stabile ad alta temperatura.

Components of Alumina Refractory Brick

Alumina refractory bricks according to resource conditions and product requirements, can be used the following types of raw materials:

To water-containing aluminum oxide minerals (diaspore, gibbsite, etc.)

As the main composition of the high bauxite; Si line stone minerals (including kyanite, andalusite, silliman stone, etc.); Synthetic raw materials, such as industrial alumina, synthetic mullite, fused corundum and so on. China's high alumina bauxite is rich in resources and excellent in texture. The resulting high alumina vanadium is mainly a mixture of two diamonds (α-Al2O3 · H 2 O) and kaolinite.

How to Identify the Quality and Grade of Alumina Refractory Brick

Identify from appearance color
First of all, identify it from the appearance color: if the color of the high-alumina brick is yellow, it is a third-grade high-alumina brick. If the color is yellowish-white, it proves that it is a second-grade high-alumina brick. brick. If the appearance of these three colors is not smooth or there is no crystal phase, it means that the sintering temperature is low and the strength is not good when used.

In addition, it depends on whether there are black spots or large areas of burnt materials on the surface of high alumina bricks. If there are black spots, it is because the iron content of the raw materials is too high, and karst holes will appear during use, which will affect the service life. It also depends on whether the surface of the high-alumina brick is smooth. If the surface is uneven, it is because the outriggers were fired during sintering, and there are large bricks on it to press, resulting in uneven surface. This also affects the staggered layer during masonry, and will also affect the service life in the later period of use.

Identify from size
The next step is to look at the size. The size should be measured with a ruler. If the length, width, and thickness of the high-alumina brick are greater than 2mm, it means that the mold scale is too large, and it may also be the reason for the raw material. above. High alumina bricks of this size cannot be used.

The quality of high alumina bricks can be seen from the bulk density
The quality of high-alumina bricks can also be seen from the bulk density. The test method is to weigh the weight of a single brick with an electronic scale, and then measure the length, width, height or size of the high-alumina brick, and then calculate Volume, divided by weight by volume, is the specific gravity of high alumina bricks. If the specific gravity is lower than 2.3, it proves to be a third-grade high-alumina brick. If the bulk density is greater than 2.3, it is a second-grade high-alumina brick. If the bulk density is above 2.45 , that is the first grade high alumina brick.

The aluminum content of refractory bricks, if the aluminum content is 55%, is the third-grade high-alumina brick, if it is 65%, it is the second-grade high-alumina brick, if it is 75%, it is the first-grade high-alumina brick, but the aluminum content is To know through chemical tests. It cannot be seen directly.

In addition, the strength, thermal shock, and reburning line changes of refractory bricks can only be known through physical and chemical processes, which cannot be seen with the naked eye.

The load softening temperature of refractory bricks is also the most important item in the use process. There are two ways to identify this. One is to look at the sintering temperature of high-alumina bricks. If the sintering temperature is 1380, then the load is around 1400. If the sintering temperature It is 1450, then the load temperature is around 1480. However, if the load softening temperature is to be more accurate, it must be tested.

The quality of high alumina bricks is judged from three intuitive methods: color, size shrinkage, and body density. Of course, if the user requires other indicators, it must be tested to find out.

How to Choose the Right Alumina Refractory Brick

Type of bricks

As we have previously learned, alumina bricks are divided into three grades: insulating, low-iron, and standard. Choose the grade that most closely matches your application needs.

Alumina content of bricks

High alumina fire bricks range from 40% to 90% alumina content. The higher the content, the greater the refractoriness and temperature resistance.

Color of bricks

Color expertise is the next important consideration when choosing high alumina bricks. The flawless high-aluminum brick surface should be lubricated, have a yellow-and-white color, and be flat on all four sides without any break angles or cracks.

Size and shape of bricks

Make sure that the high alumina fire bricks' dimensions and design complement those of your equipment or construction project.Right-ftted bricks are essential to maintaining structural integrity.

Weight of bricks

The weight of the bricks should also be taken into account; a first-grade brick should weigh 4.5 kg, a second-grade brick should weigh 4.2 kg, and a third-grade brick should weigh 4 kg. When it comes to high-aluminum bricks, the equal grade and equal parameter type can be considered excellent.

Our Factory

Locates in Fushun city of Liaoning Province, it has over 20 years' experience in technological research and production management of alumina refractory materials, a fullautomatic batching and filling production line and a manufacturing workshop of castables, covering all the alumina refractories including: Shaped products of high alumina series, mulite series, silicon series, phosphate series and light insulation series etc., and unshaped products of castable, self-flow, plastic materials and precast blocks, etc., as well as a variety of raw refractories and chemical products.

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FAQ

Q: What are alumina refractory bricks?

A: Alumina refractory bricks are high-alumina content bricks, with a minimum alumina content of 48%, known for their excellent thermal and chemical resistance.

Q: In which applications are alumina refractory bricks used?

A: They are used in high-temperature environments such as blast furnaces, incinerators, and petrochemical processing units where resistance to abrasion and thermal shock is crucial.

Q: What makes alumina bricks resist chemical corrosion?

A: Their high alumina content, which forms a protective layer against corrosive agents, makes them highly resistant to both acidic and basic slag chemical attacks.

Q: How do alumina bricks handle temperature fluctuations?

A: These bricks exhibit excellent thermal shock resistance, minimizing spalling and cracking during rapid temperature changes.

Q: What is the typical range of alumina content in these bricks?

A: Alumina content can range from 48% to 90% or more, with higher percentages enhancing the brick’s thermal properties.

Q: Are there different types of alumina refractory bricks?

A: Yes, they include fused cast, sintered, and fused alumina bricks, each with varying purity levels and uses.

Q: How do alumina bricks support high mechanical strength?

A: Their dense structure and high alumina content provide exceptional mechanical strength, making them durable even under heavy loads.

Q: Can alumina bricks be customized for specific applications?

A: Yes, they can be tailored with additional additives to meet specific thermal, physical, and chemical requirements.

Q: Is alumina brick acidic or basic?

A: Alumina, silica zirconia refractories, and fire clay bricks refractory are alkaline refractories.

Q: How does the manufacturing process of alumina bricks differ from silica bricks?

A: Alumina bricks involve calcined bauxite and other materials, mixed with binders, shaped, and fired at high temperatures to achieve a dense structure.

Q: Are alumina bricks safe to handle?

A: Handling requires care to avoid inhaling dust, which can harm lungs. PPE is recommended.

Q: Can alumina bricks be repaired or recycled?

A: Minor damages can be repaired, but major repairs often necessitate replacement. Recycling is possible but depends on the condition and composition.

Q: How do alumina bricks compare to other refractory materials in terms of cost?

A: They are generally more expensive than silica bricks but offer superior performance in demanding applications.

Q: Do alumina bricks change appearance at high temperatures?

A: Color changes might occur, typically from white to light brown, due to the formation of different alumina phases.

Q: What is the lifespan of an alumina refractory brick in industrial applications?

A: Lifespan can vary widely, from a few months to several years, depending on the application and maintenance.

Q: How do alumina bricks improve energy efficiency in industries?

A: Their high thermal conductivity reduces heat loss, decreasing energy needed to maintain high operation temperatures.

Q: Are there size and shape variations available for alumina bricks?

A: Yes, they come in various standard and custom sizes, including arches and segments for specialized furnace designs.

Q: How do alumina bricks compare to magnesium and chromia bricks in terms of thermal shock resistance?

A: Alumina bricks offer superior thermal shock resistance compared to most magnesium bricks but might not match some high-purity chromia bricks.

Q: What are the safety guidelines for storing alumina bricks?

A: Store them in a dry place free from contaminants and handle with care to prevent damage.

Q: What are alumina bricks used for?

A: Depending upon the intrinsic features, Alumina Bricks are used for the lining of varieties of equipment like Blast Furnace; Hot Blast Stoves; Cement Kilns; Glass Tank Furnace; Pot Furnace; Anode Baking Furnace; Petro-chemicals; Fertilizers; Boilers; Coke Ovens; Hot Metal Ladles etc.

As one of the most professional alumina refractory brick manufacturers and suppliers in China, we're featured by quality products and low price. Please rest assured to buy bulk customized alumina refractory brick from our factory. Contact us for sample.

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