The main reasons why magnesium oxide can be used as refractory materials are as follows:

1. High melting point: The melting point of magnesium oxide is as high as 2852 ° C, which enables it to remain solid at high temperatures and is not easy to melt.

2. Excellent thermal conductivity: the thermal conductivity of magnesium oxide is moderate, which can effectively transfer heat and make the temperature in the furnace evenly distributed.

3. Chemical stability: Magnesium oxide does not react with most acidic or alkaline substances at high temperatures, and has good chemical stability.

4. Good mechanical properties: Magnesium oxide products have good bending, compressive strength, wear resistance, impact resistance and other mechanical properties.

5. Corrosion resistance: Magnesium oxide does not react with most acidic or alkaline substances and has good corrosion resistance.

6. Non-toxic: magnesium oxide does not contain harmful substances to the human body, in line with environmental requirements.

7. Rich resources: magnesium oxide is rich in the crust, which is more economical than other refractories.

Based on the above characteristics, magnesium oxide is widely used as a refractory material, especially for high-temperature furnaces, industrial furnaces, electric furnaces and other occasions where refractory materials are required.