What Are The Precautions For Using Graphite Crucibles?

What are the precautions for using graphite crucibles?
1. After the first use or after long-term non-use, the crucible needs to be heated slowly to remove moisture and preheat, which can avoid sudden heating and cause the crucible to crack. It is usually recommended to preheat at around 200°C for 1-2 hours, and then gradually heat up to the working temperature. Graphite crucibles are very sensitive to rapid temperature changes (thermal shock). Therefore, avoid placing a cold crucible directly in a high-temperature furnace or placing a hot crucible directly on a cooling surface.
2. Use suitable melting materials and avoid using materials containing strong acids, strong alkalis, oxides, etc., which may corrode the graphite crucible. Choose suitable melting materials to minimize chemical erosion of the crucible.
3. During operation and handling, it should be placed carefully and gently to avoid impact and friction to prevent the crucible from uneven force or damage by external force. When adding materials, they should be evenly distributed to avoid partial loading; the amount of material added should not be too much to prevent the melt from overflowing the edge of the crucible.
4. When using, the furnace should be kept dry as much as possible to avoid moisture and water from entering the crucible. When the crucible is working, keep the air in the furnace circulating to avoid the formation of high concentrations of corrosive gases.
5. When carrying and loading and unloading the crucible, use special clamps to avoid direct operation with hands or other inappropriate tools.
6. Ensure that operators are trained and understand the correct operating procedures and precautions to reduce damage to the crucible caused by human operating errors.