Kiln Refractory Bricks
Applicable Temperature: <1700℃
Materials: Calcined bauxite, clay, calcined magnesium sand and other materials.
Applications: Industrial rotary kiln, cement rotary kiln, limestone rotary kiln, vertical lime kiln, etc.
Kiln Refractory Bricks for Sale
Kiln refractory bricks also called high-temperature refractory bricks, are the building material that can withstand high temperatures and chemical attacks. They are usually withstand high temperatures over 1700°C. Kiln refractory bricks are important spare parts to ensure kiln efficiency and protect kiln shells from melting at high temperatures. They have excellent heat and corrosion resistance and mechanical strength. There are many types of refractory bricks used in limestone rotary kilns and vertical lime kilns. Different types of refractory bricks are required for various materials and parts of the kiln. Choose the right kiln refractory bricks to better protect the kiln, and increase production efficiency.
Advantages of Kiln Refractory Bricks in Lime Kiln
Reduce Energy Consumption
Kiln refractory bricks have good thermal insulation capabilities, Can effectively prevent the temperature from being transferred outwards, and reduce heat loss. This reduces fuel consumption and reduces costs.
Improve Product Quality
Kiln refractory bricks provide a stable temperature for the kiln, It is conducive to even heating of limestone. Thereby improving the uniformity of limestone activity.
Extend Service Life
Kiln refractory bricks are made of special high-temperature materials that can maintain stable performance in high-temperature environments. Make the kiln service life longer.
High Security
Kiln refractory bricks have high mechanical strength and compressive properties, effectively improving the stability of the kiln, and reducing safety accidents caused by structural damage.
Refractory Bricks Types
—— Refractory bricks types are varied, differences in composition and properties. In the lime calcination kiln, we should choose the right kiln refractory bricks according to types, operating temperature, chemical environment,etc. of kiln!
High-Alumina Bricks
- Composition: Aluminum oxide (Al₂O₃) between 48% and 90%.
- Characteristics: High temperature resistance up to 1800°C. Resistance to chemical corrosion. High mechanical strength.
Magnesia Bricks
- Composition: Magnesium oxide is the main component.
- Characteristics: High temperature resistance up to 2000°C. Resistant to alkaline erosion. Good thermal shock stability.
Silica Bricks
- Composition: Silicon dioxide (SiO₂) content of 93% or more.
- Characteristics: High temperature resistance up to 1700°C. Low coefficient of thermal expansion, suitable for areas with small temperature fluctuations.
Fireclay Bricks
- Composition: Aluminum oxide (Al₂O₃) content ranges from 30% to 48%, with the rest being silicates.
- Characteristics: Medium temperature resistance up to 1200°C. Low cost and better resistance to thermal shock.
Insulating Bricks
- Composition: Lightweight materials (alumina, silicates, etc.).
- Characteristics: Temperature resistance is typically below 1200°C. Low thermal conductivity and good heat insulation, light weight.
Zirconia Bricks
- Composition: Zirconium oxide (ZrO₂) is the main component.
- Characteristics: Resistant to temperatures up to 2000°C. Excellent resistance to thermal shock. High resistance to chemical attack.
Kiln Refractory Bricks Production Process
- Raw Material Handling: Raw material handling include crushing, grinding, sieving and mixing. The refractory clay, high alumina, magnesium oxide and other raw materials are grinded into fine powder, and controlling particle size through screening. The raw materials are then mixed with a binder and water to form a uniform mud.
- Forming: Making clay into bricks, includes compression molding, extrusion molding and hand molding. Different forming method are suitable for different brick shapes. The brick shapes need to make repairs after forming, ensure the precise size and smooth surface.
- Drying: By removing the moisture from the bricks, cracking of the bricks during sintering can be effectively prevented. The drying methods have natural drying and kiln drying. The drying time according to the size and thickness of the bricks determine. It usually takes several days to several weeks to prepare for the subsequent sintering.
- Sintering: Sintering process is divided into three stages: preheating, high temperature sintering and cooling. Sintering is usually carried out using tunnel kilns, shuttle kilns or rotary kilns. The temperature of sintering depends on the type of kiln refractory bricks. And strictly control the heating rate and cooling rate to prevent bricks from cracking.
- Post-Processing: To meet the needs of use, the kiln refractory bricks after sintering need to cutting, grinding and quality inspection. Ensure the kiln refractory bricks are stable performance in subsequent use.
- Other processes: To meet customer needs and increase the performance of kiln refractory bricks. We will also use impregnation, coating and composite refractory brick manufacturing processes. Ensure the kiln refractory bricks excellent performance in high temperature resistance, corrosion resistance and mechanical strength during use.
Application
——Specific use areas and selection basis of refractory bricks
1. Preheating Area: The preheating area is located at the entrance area of the lime calcination kiln, the temperature is 300°C-900°C. This area usually uses clay brick or silica brick. Clay brick has low cost and moderate temperature resistance, suitable for low-temperature environments. Silica brick has good resistance to acid corrosion. High-temperature refractory bricks in the preheating area can provide initial insulation to reduce heat loss.
2. Calcination Area: The temperature in calcination area is 900°C-1400°C. This area usually uses high-alumina or magnesia bricks as lining. High-alumina bricks are resistant to high temperatures and can withstand thermal stress. Magnesia bricks have excellent alkali resistance and can resist the alkaline gas produced by the decomposition of limestone.
3. Cooling Area: The temperatures in the cooling area gradually decrease from 1400°C to 900°C. This area usually uses silica brick or high alumina brick as lining. The silica brick has a lower coefficient of thermal expansion and is suitable for areas with large temperature fluctuations. The high alumina brick protects the kiln from thermal shock during cooling.
4. Burning Area: This is the area where the fuel is burning, the temperatures up to 1000°C-1400°C. This area usually uses high alumina bricks or magnesia bricks as lining. The high-temperature refractory bricks can withstand the high temperature and flame impact generated by combustion and also resist alkaline attack in combustion gases.
5. Flue and Exhaust Vents: the temperatures in these two areas are 500°C-1000°C, clay bricks or silica bricks are usually used as lining. High-temperature refractory bricks can effectively resist the erosion of high-temperature flue gas.
How to Choose Kiln Refractory Bricks
Kiln Operating Temperature
Different high-temperature refractory bricks have different temperature tolerance ranges, Make sure its refractoriness is higher than the actual operating temperature of the kiln.
Size and Shape
The size and shape of high-temperature refractory bricks should match the kiln structure. Ensure the tightness and firmness of the installation. Customization is available if necessary.
Mechanical Strength
The selected high-temperature refractory bricks should have sufficient mechanical strength, not be easy to break or deform, able to withstand the mechanical pressure inside the kiln.
Thermal Shock Stability
The kiln will experience rapid heating and cooling during operation. High-temperature refractory bricks with high thermal shock stability are less likely to crack.