Heating furnaces are essential equipment in industries like metallurgy, chemical engineering, and power generation, and their stable operation relies heavily on high-quality refractory bricks. The choice of refractory bricks depends on the furnace's working temperature, thermal load, chemical environment, and structural requirements. Below is a detailed introduction to the most commonly used refractory bricks for heating furnaces, helping you select the optimal solution for your industrial needs.
Fireclay Bricks
Fireclay bricks are the most widely used basic refractory bricks in heating furnaces. Made from kaolin with about 30% Al₂O₃, they feature excellent thermal shock resistance and low cost, making them ideal for medium-temperature areas (1200–1400℃) such as furnace walls, flues, and low-temperature furnace tops. Their good thermal stability prevents cracking from rapid temperature changes, while their affordability helps control overall project costs, making them a cost-effective choice for general industrial furnaces.
High-Alumina Bricks
High-alumina bricks are upgraded alternatives to fireclay bricks, containing over 48% Al₂O₃. With higher refractoriness (1400–1600℃), better compressive strength, and stronger erosion resistance, they are suitable for high-heat-load parts like furnace linings, furnace tops, and furnace doors. Classified by Al₂O₃ content, they meet different temperature demands, making them widely used in metallurgical and chemical heating furnaces where high-temperature stability is required.
Silica Bricks
Silica bricks, with SiO₂ content above 94%, excel in high-temperature volume stability, with a load softening temperature of over 1650℃. They are mainly used in ultra-high-temperature parts such as furnace tops and regenerators, especially in oxidizing furnace atmospheres. However, their poor thermal shock resistance limits their use in areas with frequent temperature fluctuations.
Alkaline Refractory Bricks
Alkaline refractory bricks, including magnesia bricks and magnesia-alumina bricks, are designed for harsh environments. Magnesia bricks, mainly composed of MgO, can withstand temperatures up to 2000℃ and have strong resistance to alkaline slag, making them suitable for furnace bottoms and slag lines in contact with alkaline melts. Magnesia-alumina bricks improve thermal shock resistance by adding alumina, adapting to more complex working conditions.
Special Refractory Bricks
Special refractory bricks like corundum bricks (Al₂O₃ ≥90%) and silicon carbide bricks are used for critical parts. Corundum bricks resist temperatures above 1800℃ and are ideal for areas directly exposed to flames or severe slag erosion. Silicon carbide bricks offer excellent wear resistance and thermal shock resistance, suitable for furnace bottoms, flues, and other high-wear parts.
Post time: Apr-17-2026
