Alumina Bricks
Why Choose Us
QC
In the production, Kerui adhere to the use of sophisticated equipment and technology, respectively, to ensure the precision of powder ratio, improve the strength and refractories of refractory products, reduce the rate of defective products, to ensure the stability and reliability of product quality.
Excellent technical team
Kerui has a complete pre-sale technical team and standardized customer service consultation process to provide customers with the design, production, construction and maintenance of the overall furnace refractory, and help customers quickly select the appropriate furnace construction and maintenance plan.
Construction technical support
In order to give full play to the performance of refractory materials and effectively improve the service life of the kiln, a good construction scheme and execution is very important.Kerui has its own five construction teams, covering the construction and maintenance of more than 100 commonly used refractory materials for kilns in steel, non-ferrous metal smelting, petrochemical, building materials and other industries.
After-sales service!
In addition to the product quality guarantee period, our company still undertake the after-sales service obligations, and provide you with the corresponding products, seriously for you to solve the problem (the corresponding fee is charged at cost).
What is Alumina Bricks
Alumina Bricks is a kind of Alumina silicate refractory brick with Alumina content above 48%. High Alumina fire brick is mainly made of high Alumina bauxite as refractory raw material, added with other powders and binders, and then mixed into the refractory brick making machine for compression molding. After being dried, it enters the high temperature tunnel kiln and fired into refractory bricks.Due to the wide range of refractory materials and stable properties of high temperature high Alumina bricks, high Alumina bricks are used as basic materials in the field of high temperature technology. Applications include cement, glass building materials, iron and steel smelting industries, petrochemical industries, etc.; high temperature industrial furnaces for high Alumina bricks There are linings of blast furnace, hot blast furnace, electric furnace top, blast furnace, reverberatory furnace, and rotary kiln.
Benefits of Alumina Bricks
Good high temperature resistance
High Alumina refractory bricks can withstand high temperature sintering, so they are widely used in high temperature industrial equipment lining, flue, furnace roof, furnace wall and other parts.
Strong corrosion resistance
High Alumina refractory bricks have good acid and alkali corrosion resistance, and are suitable for refractory requirements in acidic, alkaline and neutral environments.
Good wear resistance
High Alumina fire bricks have good wear resistance and can cope with the wear of high-speed flue gas and solid particles.
Strong cold and heat shock resistance
High Alumina brick have good cold and heat shock performance, and can withstand sharp temperature changes without breaking.
Types of Alumina Bricks
Basic alumina bricks
Basic alumina bricks are the ones which mostly consist of basic oxides such as magnesia (mgo) and dolomite (a combination of calcium magnesium carbonate, camg(co3)2). Such materials have a very high melting point and have excellent resistance to alkaline substances. Basic refractories are mostly used in applications where they come in contact with basic (alkaline) slags, ashes, and gases. Steel plants use these alumina bricks to line the basic oxygen furnace (bof) and electric arc furnace (eaf). These environments contain basic slag formed during the steelmaking process. They are used in cement kilns as well.
Acid alumina bricks
Acid alumina bricks consists of silica (sio2) or materials rich in silica. These are designed to withstand acidic conditions and resist corrosion by acidic slags and gases. Acid refractories are widely used in industries where materials come in contact with acidic substances. Acid refractories are used in constructing glass furnaces, which operate at high temperatures and in the presence of molten glass, that can have acidic properties.
Neutral alumina bricks
These neutral alumina bricks are also known as alumina-silicate refractories. These are made of materials with balanced alumina (al2o3) and silica (sio2) composition. They have good resistance to acidic and basic environments, making them versatile for different applications. Neutral refractories are used in applications involving non-ferrous metals like aluminaum and copper. They are used in furnaces and reactors for smelting and refining processes. These refractories are also used in petrochemical plants where conditions can vary depending on acidic and basic due to the nature of the chemicals processed.
Furnace and Kiln Linings
Alumina bricks are extensively used to line the walls and roofs of furnaces and kilns in industries like cement, glass, steel, and ceramics. They protect the furnace structure from extreme temperatures and prevent heat loss, improving energy efficiency.
Incinerators and Waste Treatment Systems
Alumina bricks are employed in incinerators and waste treatment facilities to contain high temperatures and prevent the release of harmful gases. They also contribute to the efficient combustion of waste materials.
Power Generation Plants
Alumina bricks play a crucial role in power generation plants, particularly in boilers and combustion chambers. They withstand the intense heat generated during combustion and protect the boiler structure.
Foundries and Metalworking
Alumina bricks are used in foundry furnaces and metalworking processes to maintain high temperatures and prevent heat loss. They contribute to efficient metal melting and shaping.
Chemical Processing and Refining
Alumina bricks are employed in chemical processing vessels and reactors to contain high temperatures and corrosive chemicals. They protect the vessel walls and ensure safe and efficient chemical reactions.
What are Alumina Bricks properties
High Refractoriness
High Alumina bricks have a high refractory temperature, allowing them to withstand extremely high temperatures without significant deformation or structural damage.
Excellent Thermal Stability
These bricks exhibit excellent thermal stability, meaning they can maintain their physical and chemical properties under prolonged exposure to high temperatures.
Good Thermal Conductivity
High Alumina bricks have relatively high thermal conductivity, allowing them to efficiently transfer and distribute heat within refractory structures.
Low Thermal Expansion
They typically have a low coefficient of thermal expansion, minimizing the risk of cracking or spalling during thermal cycling.
Strong Chemical Resistance
High Alumina bricks have excellent chemical resistance, making them resistant to acidic and alkaline environments. They can withstand the corrosive effects of molten metals, slags, and gases.
Low Porosity
These bricks are characterized by low porosity, which contributes to their high density and improved resistance to penetration by liquids and gases.
How to Choose Alumina Bricks
Alumina Content
The first and foremost factor to consider is the Alumina content in the brick. They are classified based on the percentage of Alumina (Al2O3) they contain. Typically, bricks with higher Alumina content can withstand higher temperatures and have better thermal shock resistance. Common grades include:45% Alumina Bricks: Suitable for general-purpose applications with moderate heat.60% Alumina Bricks: Ideal for more demanding environments, providing better resistance to slag and chemical corrosion.70-85% Alumina Bricks: Best for extremely high-temperature applications, offering superior strength and durability.Selecting the appropriate Alumina content depends on the specific needs of your application. Higher Alumina content generally translates to better performance but at a higher cost.
Refractoriness
Refractoriness, or the ability to withstand high temperatures without melting or deforming, is a critical factor. High-quality high Alumina fire bricks typically have a refractoriness of 1750°C or higher. It's essential to choose bricks with the right refractoriness rating to ensure they can handle the operating temperatures of your equipment.
Thermal Shock Resistance
Thermal shock resistance refers to a material's ability to withstand rapid temperature changes without cracking or breaking. In many industrial settings, such as furnaces, bricks are subjected to frequent heating and cooling cycles. A high-quality high Alumina fire brick should have excellent thermal shock resistance to prevent premature failure.
Bulk Density and Porosity
Bulk density and porosity are key indicators of a brick's durability and thermal conductivity. High bulk density generally means higher strength and better resistance to slag and erosion. On the other hand, lower porosity ensures better resistance to chemical attacks and reduces the likelihood of the brick absorbing harmful substances.When selecting a high Alumina fire brick, check the manufacturer's specifications for bulk density and porosity to ensure they meet the demands of your application. Typically, a good quality high Alumina fire brick should have a bulk density of around 2.3-3.0 g/cm³ and low porosity, preferably below 20%.
Process of Alumina Bricks
Raw Materials of Alumina Bricks
Each batch of raw materials must be issued with a product warranty and three sampling tests according to the indicators on the warranty: index test, physical and chemical performance test, re-fired furnace burn test, qualified before being put into production, must be carried out before being put into production .The pickling and iron absorption secondary finishing process makes the quality of the raw materials reach the best condition for the production of the refractory products.
Alumina Bricks Mixing
The raw material preparation personnel shall be formulated in strict accordance with the process ratio requirements formulated by the technical department. Accurate weighing must be done during the preparation process and mixed on time. The specific operation is as follows: the fine powder of less than 100 mesh needs to be premixed first, and passed through the 24 mesh sieve 2 times. After the binder is brewed, it needs to be volted for more than 24 hours. The accumulated mixing time should not be less than 20 minutes. On the day of the day, in order to avoid the remaining mixing, and to do the cleanliness of the site to ensure the purity of raw materials.
Forming and Inspection
The molding method adopted in the molding process needs to be formulated according to the structure of the product, but no matter what molding method is adopted, special attention should be paid to the structure of the product during the mold installation process. The first semi-finished product formed during the molding process must be After the inspection is passed, the production can be continued, and the product model, net weight and production date should be marked on all the semi-finished products. The label should be clear for quality follow-up inspection. At the same time, the operator must perform self-checking and self-picking, and actively reject the defective products. The quality inspector should check it one by one according to the size of the drawings to ensure that the size is correct.
Dry Pressed Clay Bricks
After passing the inspection, the semi-finished products shall be allowed to dry in the designated place for 2-3 days before entering the drying kiln. In the drying kiln.Firstly, it is dried at a low temperature of about 25-30 °C for 3-5 days, then moved to a high temperature of 50-65 °C for forced drying for 7-15 days. During the whole drying process, the operator should be careful. Be cautious to avoid the occurrence of missing corners in the semi-finished products. At the same time, the operator should fill in the dry record and indicate the date of manufacture so that the firing can proceed smoothly.
Firing Alumina Bricks
The kiln operators must strictly follow the firing curve formulated by the technical department during the firing process. Because the temperature difference of the firing of the bricks is small, the temperature control should be adjusted according to the data of the automatic tester. During the firing process, the operator should fill in the actual temperature increasing record. During the process of loading the kiln, it should be handled with care, reduce the damage caused by humans, and assist the relevant personnel to fill out the clear kiln list and the kiln list. Strive to complete the firing task of ceramic burner products on time and in quality.
Packaging and Shipping
The finished product shall be packaged in time on the premise that all tests are qualified and the quantity meets the requirements of the number of contracts. The supply department shall provide the corresponding packing boxes and fillings in advance according to the requirements of the users, and deliver them in accordance with the delivery deadline of the contract. In the process of shipping, it should be carried out in strict accordance with the delivery procedures, and issue corresponding procedures and product physical and chemical indicators test report sheets and product certification.
How to use High Alumina Bricks efficiently
Proper Selection for the Application
The first step in using high Alumina fire bricks efficiently is selecting the right type for your specific application. High Alumina fire bricks come in various grades, with different Alumina content levels ranging from 45% to over 85%. The choice of brick should be based on the operating conditions, such as temperature, chemical exposure, and mechanical stress.45-60% Alumina Bricks: Best for moderate temperature applications like secondary linings or in areas with less chemical exposure.
Correct Installation Techniques
Installation plays a critical role in the performance of high Alumina fire bricks. Incorrect installation can lead to gaps, misalignment, and uneven heating, which can cause premature failure or reduce the efficiency of the bricks.Pre-Laying and Cutting: Before installation, bricks should be pre-laid to check for alignment and size fitting. This helps in minimizing gaps and ensuring a tight fit.
Regular Maintenance and Inspection
Even the best quality high Alumina fire bricks require regular maintenance to function efficiently. Regular inspection helps in identifying early signs of wear, such as cracks, spalling, or erosion, allowing for timely repairs or replacements.Routine Checks: Regularly inspect the brickwork for any visible damage. Pay special attention to areas exposed to the highest temperatures and chemical attacks.
Optimizing Operating Conditions
Operating conditions, such as temperature and chemical exposure, should be carefully controlled to use high Alumina fire bricks efficiently.Temperature Control: Avoid exposing bricks to temperatures beyond their rated capacity. Overheating can cause thermal expansion and cracking, leading to premature failure.Chemical Exposure: Minimize exposure to corrosive chemicals by using protective coatings or barriers. In environments where chemical exposure is unavoidable, select bricks with enhanced chemical resistance.
Kerui Refractory has now become one of the powerful refractory enterprises in the research, development, production and sales of refractory products, and its product uses cover the use of refractory materials for high-temperature kilns and equipment in metallurgy, chemical industry, building materials, electric power, military industry, non-ferrous metals, carbon industry and other industries. Kerui Refractory produces 150000 tons of sintered products and 100000 tons of unshaped refractory materials annually. The company has four plants, namely heavy bricks, light bricks, unshaped bricks and fused bricks.
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