What is a primary reason for using crucibles in high-temperature applications?

Using crucibles in high-temperature applications is primarily due to their resistance to high temperatures. Crucibles are made from materials that can withstand extreme heat without melting or degrading, which is essential for processes like metal melting, chemical reactions, and high-temperature experiments. This thermal stability ensures that the crucible will maintain its structural integrity and not react with the substances inside, allowing for accurate and safe experiments.

While affordability and disposability can be advantages in specific contexts, they are not primary reasons for using crucibles in high-temperature scenarios. Transparency is not a characteristic needed for the function of a crucible, and while having a lightweight design may facilitate handling, it is not a critical aspect when dealing with high-temperature processes where durability is of utmost importance. Thus, the main reason revolves around their ability to endure and function effectively at elevated temperatures.