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Silica Crucible

A silica crucible is a container made from silica (SiO₂), typically fused quartz or fused silica, used for high-temperature applications due to its excellent thermal stability and chemical inertness. Here’s a concise overview based on available information:

• Material Properties:

1. High Melting Point: Fused silica can withstand temperatures up to ~1,650–1,700°C, making it ideal for processes like metal melting, crystal growth (e.g., Czochralski process for silicon wafers), and high-temperature chemical reactions.
2. Low Thermal Expansion: Minimizes cracking under rapid temperature changes.
3. Chemical Purity: Resistant to most acids and chemicals, except hydrofluoric acid and strong alkalis, ensuring minimal contamination in processes.
4. Transparency: Fused quartz is often transparent to UV and IR, useful in optical and semiconductor applications.

• Types:

1. Fused Quartz: Made by melting natural quartz crystals; slightly less pure but cost-effective.
2. Fused Silica: Synthetic, higher purity, used in precision applications like semiconductor manufacturing.
3. Available in opaque or transparent forms, with shapes like cylindrical, conical, or custom designs.

• Applications:

1. Semiconductor Industry: Used in silicon wafer production for microchips.
2. Metallurgy: Melting metals like platinum, gold, or alloys.
3. Laboratory Use: For calcination, ash determination, or high-temperature experiments.
4. Glass and Ceramics: Melting and shaping high-purity materials.

• Specifications (based on typical products):

1. Sizes range from small (e.g., 10 mL) to large (e.g., 500 mL or more).
2. Wall thickness typically 1–3 mm for durability.
3. Can include lids for contamination control or gas-tight environments.

• Considerations:

• Thermal Shock: Gradual heating/cooling is required to prevent cracking.
• Purity Needs: Synthetic fused silica is preferred for ultra-high-purity applications.
• Cost: Fused silica crucibles are more expensive than quartz due to manufacturing complexity.