Industry Knowledge of Magnesia Refractory Bricks

Magnesia refractory bricks are a type of refractory material made from magnesia minerals. They are widely used in high-temperature furnaces and kilns due to their excellent thermal stability and resistance to corrosion. In this article, we will talk about the classification, technical parameters, and production process of magnesia refractory bricks.

Classification:
Magnesia refractory bricks can be classified into different grades based on their magnesia content, density, and compressive strength. The common grades include magnesia bricks, high-purity magnesia bricks, burned magnesia bricks, and electrical grade magnesia bricks. The selection of the grade is determined by the service conditions of the furnace, such as temperature, atmosphere, and chemical environment.

Technical parameters:
The technical parameters of magnesia refractory bricks mainly include the magnesia content, apparent porosity, bulk density, compressive strength, thermal conductivity, and thermal expansion coefficient. The magnesia content is the most critical factor for the performance of magnesia refractory bricks. The higher the magnesia content, the better the thermal stability and resistance to corrosion. The apparent porosity should be appropriately controlled to prevent the penetration of the molten slag or gas. The bulk density and compressive strength are related to the structural stability of the furnace lining. The thermal conductivity and thermal expansion coefficient are essential for the heat transfer and thermal shock resistance.

Production process:
The production process of magnesia refractory bricks involves several steps, including raw material preparation, mixing, shaping, drying, and firing. The raw materials are generally magnesite, dolomite, or brucite, which are crushed and screened into a suitable size. Then, the raw materials are mixed with a binder and additives to form a plastic mass. The plastic mass is pressed into a specific shape by a press machine, and then dried in the air or in a tunnel dryer. Finally, the shaped bricks are fired in a high-temperature kiln at a temperature of 1550-1750℃ to obtain the required properties. The firing process is critical for the quality of magnesia refractory bricks, and the cooling process should be controlled to avoid thermal shock.

In conclusion, magnesia refractory bricks have significant applications in various industrial fields due to their excellent performance. The proper selection of the grade and the reasonable control of the technical parameters and production process are crucial for the quality and service life of magnesia refractory bricks.