How to Correctly Understand the Basic Characteristics of Refractory Bricks

Refractory bricks, as core refractory materials in high-temperature industries, are widely used in kiln linings in industries such as steel, cement, glass, and metallurgy. Their performance directly determines the operational stability and service life of equipment. Correctly understanding the basic characteristics of refractory bricks is crucial for selection, construction, and subsequent maintenance, effectively reducing production losses and costs.

High refractoriness is the core foundation and the most essential characteristic of refractory bricks. It refers to the critical temperature at which they do not soften or melt at high temperatures, typically needing to reach above 1700℃ to be suitable for industrial kiln conditions. The refractoriness of refractory bricks varies significantly depending on the material. For example, clay bricks have a refractoriness of approximately 1730-1770℃, while high-alumina bricks can reach 1770-1830℃. Alkaline refractory bricks, such as magnesia-chrome bricks, can withstand extreme temperatures above 1800℃. Therefore, precise matching based on the actual operating temperature of the kiln is necessary during selection.

Excellent thermal shock resistance is indispensable. Industrial kilns frequently experience temperature fluctuations. Including rises and falls. Refractory bricks must withstand the thermal stress caused by these sudden temperature changes without cracking. Thermal shock resistance is closely related to the material’s coefficient of thermal expansion and thermal conductivity. For example, lightweight clay insulating bricks, through optimized pore structure, can improve thermal shock resistance while maintaining insulation performance, extending their service life during kiln start-up and shutdown.

Erosion resistance determines service life. High-temperature molten slag, gases, and molten metal within the kiln cause chemical erosion and physical scouring of the bricks. Erosion resistance directly affects the service life of refractory bricks. Acidic refractory bricks are suitable for acidic environments, while basic refractory bricks can resist alkaline slag erosion. Neutral refractory bricks, such as high-alumina bricks and corundum bricks, possess broad-spectrum erosion resistance, making them suitable for complex operating conditions.

Mechanical strength and structural stability are essential. Refractory bricks must withstand the pressure of construction, material impact, and their own weight at high temperatures. Therefore, they must possess sufficient mechanical strength at both room and high temperatures. Meanwhile, the low porosity and uniform microstructure reduce media penetration and improve the density of the brick, preventing problems such as peeling and cracking during use.
Mechanical strength and structural stability are essential. Refractory bricks must withstand the pressure of construction, material impact, and their own weight at high temperatures, requiring sufficient mechanical strength at both room and high temperatures. Meanwhile, the low porosity and uniform microstructure reduce media penetration. Improve the density of the brick, preventing problems such as peeling and cracking during use.