Why is Magnesia Used in Bricks?

August 29, 2023

Magnesia, a compound derived from magnesium oxide (MgO), plays a significant role in various industries due to its exceptional properties. One of its most notable applications is in the production of magnesia bricks, which are widely used in refractory applications. In this article, we will explore the reasons behind the use of magnesia in bricks, examining its unique characteristics and the industries that benefit from its inclusion.

Magnesia bricks

Understanding Magnesia

Magnesia, also known as magnesite or magnesia oxide, is a white, odorless, and tasteless alkaline earth metal compound. It is naturally occurring and can be obtained from minerals like magnesite and dolomite. What makes magnesia particularly valuable in refractory applications is its remarkable combination of properties:

1. High Melting Point: Magnesia has an extremely high melting point, making it capable of withstanding temperatures well above 2,800°C. This property is crucial in applications that involve intense heat.

2. Heat Insulation: Magnesia is an excellent insulator of heat. It can maintain high temperatures within a confined space while preventing heat from escaping, thus increasing energy efficiency.

3. Chemical Inertness: It exhibits a high resistance to chemical corrosion, especially from basic compounds, such as alkaline substances. This resistance is a key factor in its widespread use.

4. Low Thermal Expansion: Magnesia has a low coefficient of thermal expansion, which means it does not expand significantly when exposed to high temperatures. This property minimizes the risk of cracking and structural damage under extreme heat.

Applications of Magnesia in Bricks

1. Steel Industry

The steel industry is one of the primary beneficiaries of magnesia's inclusion in bricks. Steelmaking involves extremely high temperatures, and the lining of furnaces and ladles must endure harsh conditions. Magnesia bricks, with their high melting point and resistance to basic slag corrosion, are ideal for this purpose. They help maintain the structural integrity of the furnace and ladle linings, ensuring consistent and efficient steel production.

2. Cement Industry

In the cement industry, rotary kilns used for clinker production operate at temperatures exceeding 1,400°C. Magnesia bricks are the material of choice for lining these kilns. Their ability to withstand high temperatures and resist the corrosive effects of alkaline materials is vital for extending the kilns' lifespan and enabling cost-effective cement production.

3. Glass Industry

The glass industry relies on magnesia bricks to line regenerators and glass melting furnaces. Glass production involves extremely high temperatures, and these bricks provide excellent heat resistance and minimal thermal expansion. This ensures the stability of the furnace structure and extends the service life of these critical components.

4. Non-Ferrous Metallurgy

In non-ferrous metallurgy, particularly in the smelting of metals like copper and nickel, magnesia bricks find extensive use. The smelting furnaces in these operations operate at elevated temperatures, and the resistance to corrosion and thermal stress exhibited by magnesia bricks is crucial for their performance and longevity.


The use of magnesia in bricks is driven by its exceptional properties, which include high heat resistance, thermal insulation, chemical inertness, and low thermal expansion. These characteristics make magnesia an ideal material for refractory applications in industries that require the handling of extreme temperatures and corrosive environments.

From the steel and cement industries to glass production and non-ferrous metallurgy, magnesia bricks play a pivotal role in maintaining the integrity and efficiency of critical equipment and structures. Despite certain challenges, such as susceptibility to hydration when exposed to moisture and the relatively higher cost compared to other refractory materials, the overall performance and reliability of magnesia bricks make them an indispensable choice for demanding applications.

As industries continue to evolve and demand even greater performance from refractory materials, magnesia's role in bricks is likely to remain at the forefront of innovation and application, ensuring the continued advancement of industrial processes that rely on extreme temperatures and resistance to corrosion. We are a magnesia brick supplier. If you are interested in our products, please contact us now!

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