Silicon carbide crucible is an important smelting tool in the metallurgical industry. Due to its excellent high temperature resistance and thermal conductivity, it is widely used in various metal smelting and chemical reactions. However, to ensure optimal performance during use, silicon carbide crucibles need to be properly preheated.
Preheating steps for silicon carbide crucible
Silicon carbide crucibles require special care during the preheating process to prevent problems such as thermal expansion, bottom detachment, delamination or cracking caused by residual moisture. Specific steps are as follows:
Initial baking: Bake in the oven without adding any materials, and maintain the temperature for more than 24 hours. During this process, rotate the crucible regularly to ensure uniform heating and completely remove moisture from the walls of the crucible.
Gradually heat:
First preheat the crucible to 150 to 200 degrees Celsius and hold for 1 hour.
Then, increase the temperature at a rate of 150 degrees Celsius per hour until a higher temperature is reached. During this process, avoid leaving the crucible walls at temperatures between 315 and 650 degrees Celsius for too long, as the crucible will oxidize rapidly in this temperature range, shortening its life and reducing its thermal conductivity.
High temperature treatment:
After preheating is completed, unless the crucible is exposed to a humid environment again, it does not need to be preheated again and can continue to be used.
After preheating is completed, quickly raise the temperature to 850~950 degrees Celsius, keep it warm for half an hour without adding materials, then cool down to normal operating temperature and start adding materials. This treatment can effectively extend the service life of the crucible.
Other preprocessing methods
In addition to the above preheating steps, the following methods can also be used:
Preheat next to an oil burner: Placing the crucible next to an oil burner can help remove moisture.
Burning charcoal or wood: Burning charcoal or wood in a crucible can further help remove moisture.
Choosing the correct crucible size
Silicon carbide crucible dimensions vary depending on the manufacturer and specific application. Therefore, when selecting, please refer to specific product specifications or consult the supplier for accurate information. Choosing the right crucible based on your needs can improve production efficiency and product quality.
By following the correct preheating and processing procedures, silicon carbide crucibles can maximize their performance and extend their service life, providing a reliable guarantee for your production process.
Graphite Crucible User Guide
Graphite crucibles are also widely used in high temperature experiments and industrial production. Its high temperature resistance, corrosion resistance, and good thermal conductivity make it ideal for many experiments and production processes. In order to ensure the best performance and long service life of the graphite crucible, the following stages should be paid attention to during use:
Sample placement
Solid sample: Evenly distribute the test substance or raw material in the graphite crucible to avoid local overheating or splashing.
Liquid samples: Use a dropper or other micro-sampling tool to drop liquid into the crucible to avoid splashing or contaminating the outside of the crucible.
heating operation
heating method:
Use electric heating devices, infrared radiation heating or other appropriate heating methods to heat the graphite crucible.
Avoid direct heating with an open flame. Because high-purity graphite has a high thermal conductivity, direct heating with an open flame may cause the crucible to deform or crack.
Heating speed:
Maintain an appropriate heating rate to avoid damaging the crucible due to sudden temperature changes.
Adjust the position and power of the heating device to ensure that the crucible is heated evenly.
Precautions
Avoid direct contact with the flame: When heating, avoid direct contact with the flame to avoid leaving black marks on the bottom of the crucible or causing other damage.
Temperature control: Graphite crucible is sensitive to temperature changes, so the heating temperature must be controlled during use to avoid the crucible rupturing due to too high or too low temperature.
Environmental cleanliness and safety: Keep the surrounding environment clean and avoid damage to the graphite crucible due to impact or falling from heights.
Professional data support
Thermal conductivity: The thermal conductivity of high-purity graphite crucible is about 100-300 W/m·K, which enables it to quickly transfer heat at high temperatures and reduce the stress effect of temperature gradient on the crucible.
Operating temperature: Graphite crucible has excellent high temperature resistance, the maximum operating temperature can reach 3000°C, and is best used in an inert atmosphere.
Oxidation resistance: When used at high temperatures in the air, the surface of graphite crucible is prone to oxidation. Protective measures such as applying anti-oxidation coating or using inert gas protection should be taken.
Strictly adhering to the above methods and precautions can ensure the high efficiency and long life of graphite crucibles and silicon carbide crucibles, thereby improving the reliability and quality of experiments and production.
Post time: Jul-11-2024