Magnesia-chrome brick and refractory brick are two different refractory materials, which are obviously different in composition, performance, application and production technology. The following are their main differences:

I. Composition and structure

Magnesia-chrome brick:

Main components: High-purity magnesium oxide (MgO) and chromium trioxide (Cr₂O₃) are the main components, and usually a small amount of silicon dioxide (SiO₂) and aluminum oxide (ALO) are also included.

Structural characteristics: the crystal phases of magnesia-chrome brick are directly combined, and the glass phase is concentrated in the triangular area of the crystal phase. This structure endows it with high high temperature strength and chemical erosion resistance.

Refractory bricks:

Composition diversity: Refractory bricks have a wide range of components, such as clay bricks (mainly composed of ALO and SiO), high-alumina bricks (with high ALO content) and silicon bricks (mainly composed of SiO).

Structural characteristics: The structure of refractory bricks varies with different components, and usually has high density and certain porosity to meet different application requirements.

II. Performance

Magnesia-chrome brick:

High temperature performance: it has a high load softening temperature (usually between 1580℃ and 1700℃) and can maintain high structural strength in high temperature environment.

Chemical corrosion resistance: Strong corrosion resistance to acidic, alkaline and oxidizing substances, especially suitable for complex chemical environment.

Thermal shock stability: the thermal shock stability of magnesia-chrome brick can be significantly improved by optimizing the formula and process.

Refractory bricks:

High temperature performance: The load softening temperature of different types of refractory bricks is quite different. For example, the load softening temperature of clay brick is usually around 1300℃, while the load softening temperature of high alumina brick and silicon brick is higher.

Chemical erosion resistance: the chemical erosion resistance of refractory bricks varies with different compositions. For example, clay bricks have strong corrosion resistance to acidic substances, while high-alumina bricks have better corrosion resistance to alkaline substances.

Thermal shock stability: the thermal shock stability of general refractory bricks is relatively poor, but its thermal shock resistance can be improved under some special formulas and processes.

III. Uses

Magnesia-chrome brick:

Main uses: Widely used in high-temperature equipment such as sintering zone of cement rotary kiln, glass melting furnace, iron and steel smelting electric furnace, converter and nonferrous metal smelting furnace.

Special purpose: Because of its excellent chemical corrosion resistance, magnesia-chrome brick is also commonly used in some special working conditions that require high corrosion resistance.

Refractory bricks:

General purpose: Refractory bricks are widely used, covering almost all high-temperature industrial fields, such as steel, cement, glass, ceramics and chemical industry.

Specific purposes: Different types of refractory bricks are suitable for different working conditions. For example, clay brick is suitable for general high-temperature furnace lining, high-alumina brick is suitable for equipment that requires high refractoriness, and silicon brick is suitable for glass melting furnace.

IV. Production technology

Magnesia-chrome brick:

High requirements for raw materials: the production of magnesia-chrome bricks needs high-purity magnesia and chrome ore concentrate as raw materials, and has strict requirements on the purity and impurity content of raw materials.

High-temperature sintering: It is usually necessary to sinter in a high-temperature furnace above 1500℃ to ensure the direct combination of crystal phases.

Strict quality control: chemical composition, physical properties and appearance quality need to be strictly controlled in the production process.

Refractory bricks:

Variety of raw materials: There are many kinds of raw materials for refractory bricks, including clay, bauxite, silica, etc., and the requirements for the purity of raw materials are relatively low.

Wide sintering temperature range: the sintering temperature varies with the type of brick, ranging from 1000℃ to 1600℃.

Flexible production process: the production process of refractory bricks is relatively flexible and can be adjusted according to different use requirements.

V. Cost and price

Magnesia-chrome brick:

Higher cost: The production cost of magnesia-chrome brick is relatively high due to the high purity of raw materials and complicated production process.

Higher price: The price of magnesia-chrome bricks is usually higher than that of ordinary refractory bricks, especially in high-purity and high-performance products.

Refractory bricks:

Large cost difference: the cost of refractory bricks varies greatly due to different types and raw materials. For example, the cost of clay brick is lower, while the cost of high alumina brick and silicon brick is higher.

Wide price range: the price range of refractory bricks is wide, from low-grade clay bricks to high-grade special refractory bricks, the price difference is significant.

VI. Environmental impact

Magnesia-chrome brick:

Potential environmental problems: Chromium (Cr) may be released during the production and use of magnesia-chrome bricks, which is a harmful substance and potentially harmful to the environment and human health.

High environmental protection requirements: strict environmental protection measures should be taken during production and use to reduce the emission of hexavalent chromium.

Refractory bricks:

Small environmental impact: Most refractory bricks have relatively small environmental impact, but in some cases (such as refractory bricks containing heavy metals), environmental protection measures are also needed.

VII. Summary

The main differences between magnesia-chrome bricks and refractory bricks are composition, performance, use, production technology, cost and environmental impact. Magnesia-chrome brick is suitable for specific high temperature and complex chemical environment because of its excellent high temperature performance and chemical erosion resistance. Refractory bricks, on the other hand, are suitable for various high-temperature industrial fields because of their diverse components and wide uses. When selecting refractory materials, factors such as performance, cost and environmental protection should be considered comprehensively according to specific working conditions and requirements.