Why is magnesium oxide used as a refractory material?

Explanation

**Step-by-Step Solution:**

1. **Definition of Refractory Materials**: Refractory materials are those that can withstand high temperatures without melting or breaking down. They are essential in applications such as furnace linings, kilns, and reactors.

2. **Properties of Magnesium Oxide**: Magnesium oxide (MgO) is known for its excellent thermal stability. It has a high melting point of approximately 2800 degrees Celsius.

3. **High Melting Point**: The high melting point of magnesium oxide makes it suitable for use in environments that experience extreme heat. This property ensures that it remains solid and functional even at elevated temperatures.

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