Beryllia crucibles used for melting uranium and thorium outperform alumina at high temperatures (> 1900°C ) in all aspects except for?
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Answer: A. Cost
Explanation
Beryllia outperforms alumina in melting point, thermal conductivity, and electrical resistance at ultra-high temperatures. However, beryllium oxide is extremely expensive to produce and process compared to widely available alumina ceramics. High material and manufacturing costs restrict beryllia crucible usage to specialized nuclear and advanced research applications. Beryllia and alumina are high-performance oxide ceramics used as crucibles for melting reactive nuclear metals. Uranium and thorium require ultra-high melting crucibles that do not contaminate the metal during vacuum induction melting. Beryllium and its compounds pose severe inhalation toxicity hazards requiring strict industrial hygiene safety protocols.
Cost is the correct exception because beryllia is exceptionally expensive compared to standard industrial alumina. Electrical conductivity is superior in beryllia at high temperatures, making it a better insulator than alumina. Thermal conductivity is exceptionally high for beryllia, outperforming alumina significantly at elevated operating temperatures.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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