New Furnace Dry Burning Purification: A Crucial Step That Cannot Be Ski"&"pped Before High-Purity Product Production
About three years ago, a customer who made semiconductor-grade graphite was eager to put his new equipment into production as soon as it was installed and debugged. I understood his feelings—the project "&"schedule was tight, and of course, he wanted to use the equipment as soon as it arrived. But I stopped him at the time, saying, ""Don't rush, there's still an important step that hasn't been done: high-temperature dry burning purification."" He didn't qui"&"te understand at the time, thinking that the equipment had already been tested before leaving the factory, so why burn it again? He probably thought it was just a pure waste of electricity.
I told him that factory testing, dry burning, furnace dry"&"ing, and high-temperature purification are two different things.
- Moisture: Atmospheric moisture adsorbed on insulation materials and metal surfaces
- Grease: Residual processing oils and"&" rust-preventive oils from the manufacturing process
- Volatile Organic Compounds: Residual adhesives and organic matter released from packaging materials
- Surface Oxide Layer: Decomposition of the oxide "&"film on the metal surface under high-temperature reducing atmosphere
Standard Dry Burn Process
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Completely replace the air inside the furnace with a protective gas (high-purity nitrogen or argon).
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Slowly raise the temp"&"erature to 150-200℃ under full vacuum, hold for 2-4 hours to allow moisture to evaporate fully, and use a vacuum pump to remove the sublimated water vapor from the furnace.
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Continue to slowly raise the temperature under full vacuum to 800-1000℃,"&" hold for 4-8 hours to remove organic matter.
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Raise to the maximum operating temperature and hold for several hours to ensure thorough degassing of all components inside the furnace.
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After cooling, check the vacuum level or background "&"impurity concentration to confirm compliance.
The entire process may require repeated 2-3 cycles, taking several days, until the furnace background environment meets the process requirements and the temperature reaches the"&" level specified in the contract before delivery to the customer.
The customer later followed the advice and performed dry-firing purification, and the purity of the first batch of products met the standards. However, another competitor, rushing to st"&"art production at the same time, skipped this step, resulting in the entire first batch of semiconductor-grade graphite failing to meet purity standards, leading to huge losses. The dry-firing and high-temperature purification process for new furnaces is "&"absolutely essential and cannot be omitted.")
