There are significant differences between dense refractory bricks and ordinary refractory bricks in composition, structure, performance and application. The following is a detailed comparison:

I. Composition and structure

Composition:

Dense refractory bricks: usually contain high alumina (Al₂O₃) content, generally between 45% and 85%. In addition, ingredients such as flint clay or kyanite will be added to improve its density.

Ordinary refractory brick: the composition is relatively simple, mainly composed of refractory clay, alumina and silica, and the alumina content is usually between 30% and 45%.

Structure:

Dense refractory brick: it has low porosity and high density, and its structure is more compact.

Ordinary refractory bricks: relatively high porosity and low density.

II. Performance

(1) Fire resistance:

Dense refractory bricks: The fire resistance is usually above 1770℃, and the fire resistance of some high-alumina bricks can reach 1850℃.

Ordinary refractory brick: the fire resistance is generally between 1580℃ and 1770℃.

(2) Corrosion resistance:

Dense firebrick: Because of its low porosity, it has stronger corrosion resistance, especially in acid corrosion resistance, which is one to two times higher than that of ordinary firebrick.

Ordinary refractory brick: the corrosion resistance is relatively weak, which is more suitable for general high temperature environment.

(3) Strength and wear resistance:

Dense refractory brick: it has higher compressive strength and wear resistance, and is suitable for high temperature and high mechanical stress environment.

Ordinary refractory brick: with low strength and wear resistance, it is more suitable for high temperature environment with light load.

(4) Thermal conductivity:

Dense refractory brick: Low thermal conductivity and better thermal insulation performance.

Ordinary refractory bricks: high thermal conductivity and relatively poor thermal insulation.

III. Appearance and color

Dense firebrick: The color is usually reddish, which is the result of adding flint clay and other ingredients.

Ordinary refractory brick: the color is generally yellow and white.

IV. Applications

Dense refractory brick:

Suitable for high temperature and high corrosive environment, such as the melting part of glass kiln, the key part of cement kiln and the melting pool of nonferrous metal smelting furnace.

Because of its excellent corrosion resistance and wear resistance, the service life is longer.

Ordinary refractory bricks:

Suitable for general high temperature environment, such as lining of ordinary industrial furnace.

Low cost, suitable for occasions with low requirements on fire resistance.

V. Price

Dense firebrick: Because of its higher density and more complicated production process, the price is relatively high.

Ordinary refractory brick: the price is relatively low.

VI. Service life

Dense firebrick: Because of its low porosity and high erosion resistance, its service life is usually one to two times longer than that of ordinary firebrick.

Ordinary refractory bricks: the service life is relatively short.

VII. Summary

Dense refractory bricks and ordinary refractory bricks have their own advantages and disadvantages, and the choice of which brick depends on the specific application requirements. If higher fire resistance, corrosion resistance and wear resistance are needed, dense refractory bricks are a better choice; If the application environment does not require high fire resistance, ordinary refractory bricks are more cost-effective.