Alumina Conical Crucible for Lab Ashing & High-Temperature Processing

Tapered Wall Alumina Crucible Applications

• Lab Ashing & Gravimetric Analysis (Quality/Environmental Labs)

  ✅ Key Advantages

  1. Cleaner residue recovery via conical apex; minimizes sample loss on transfer.
  2. Compatible with 500–600 °C ashing setpoints in muffle furnaces; stable through repeats.
  3. Lid options reduce airborne contamination and volatilization loss.

  ✅ Problem Solved

  During routine ash testing with 500–600 °C cycles, a lab reduced re-runs after switching to conical alumina crucibles with vented lids, citing easier pour-out and fewer spill losses. Re-run rate dropped from an estimated 8–10% to <3% over a quarter, improving throughput without changing furnace recipes.

• Small-Batch Melting & Alloy Screening (R&D/PM)

  ✅ Key Advantages

  1. High-temperature window (~1600–1750 °C) supports trial melts under controlled ramps.
  2. High-purity Al₂O₃ avoids carbon pickup compared with graphite in sensitive systems.
  3. Low CTE helps maintain vessel integrity through heat–cool cycles.

  ✅ Problem Solved

  An R&D cell screening small alloy buttons limited cracking by holding ≤5 °C/min ramps and using heavy-wall conical alumina vessels; scrap from crucible failure fell noticeably after enforcing ramp discipline documented for alumina ware.

• Calcination & Drying of Powders (Materials Labs)

  ✅ Key Advantages

  1. Shape promotes uniform bed depth and consistent exposure.
  2. Chemically inert to most acids/alkalis during pre-treatments.
  3. Conical form aids complete decanting prior to milling or analysis.

  ✅ Problem Solved

  Powder lots previously left 1–2 % hold-up in flat vessels; switching to conical alumina cut retained mass below 0.5 % on typical 50–100 mL batches, improving mass balance and cycle time.

Alumina Conical Crucible Usage Instructions

• Operation

  1. Check condition before use: Examine the crucible carefully for surface cracks or chips. Always match it with the correct lid size to ensure proper fit and minimize contamination.
  2. Control heating and cooling rates: Increase temperature gradually at about 3–5 °C per minute unless your process has been validated for faster ramps. Avoid rapid loading or unloading at high temperature to reduce thermal shock.
  3. Follow recommended ashing procedures: For gravimetric or environmental analysis, maintain common ashing temperatures around 500–600 °C. After completion, allow the crucible to cool to near room temperature before weighing to prevent errors from heat distortion.

• Storage & Cleaning

  1. Let crucibles cool on a refractory plate or furnace shelf; do not quench in water or other liquids.
  2. After aqueous cleaning, dry completely before reuse. Avoid aggressive reagents such as hydrofluoric acid or strong hot alkalis, which can attack alumina and shorten service life.
  3. Store crucibles in a clean, dry cabinet, ideally separated by foam or carton dividers to prevent edge chipping.

• Common Misuse & How to Fix

  1. Cracks or breakage after cycles
  a.Likely caused by excessive ramp speed, uneven sample loading, or sudden temperature changes.
  b.Prevent by keeping heating/cooling rates ≤5 °C/min, balancing sample distribution, and ensuring the furnace has uniform temperature zones.

  2. Residue contamination or dust fall-in
  a.It can result from open exposure during high-temperature operation.
  b.Use a vented lid to shield samples from airborne particles while still allowing gases to escape. Always check tongs, trays, or liners for cleanliness before handling.

  3. Warping or a loose lid fit over time
  a. Often due to repeated cycling at maximum temperatures.
  b. Rotate crucibles in use, avoid extended exposure above continuous-use limits, and replace lids when surface wear affects sealing.

Tapered Wall Alumina Crucible FAQ

1. Q: Why choose a conical alumina crucible instead of cylindrical?
   A: The conical shape consolidates residue for easier pour-out and gravimetric weigh-back, useful in ashing workflows.
2. Q: What is the maximum temperature for an alumina conical crucible?
   A: It can handle continuous use around 1600 °C and short-term peaks up to 1750 °C, depending on wall thickness and grade.
3. Q: Do you have alumina conical crucibles with lids for sale?
   A: Yes, ADCERAX is supplied in alumina conical crucibles with flat lids, recessed lids, or vented lids. Lids help reduce contamination and prevent volatile loss during heating.
4. Q: Can I order custom dimensions for alumina conical crucibles?
   A: Absolutely. Buyers can specify inner/outer diameter, wall thickness, height, cone angle, and ID marking for traceability.
5. Q: Are alumina conical crucibles resistant to chemicals?
   A: Yes, alumina is resistant to most acids, alkalis, and molten salts, but it should not be used with hydrofluoric acid or strong hot caustics.
6. Q: How should I heat an alumina conical crucible to avoid cracking?
   A: Maintain a ramp rate of ≤5 °C per minute and avoid sudden cooling or uneven loading. This reduces thermal stress and extends service life.
7. Q: Where can I buy alumina conical crucibles in bulk?
   A: ADCERAX, a factory-direct manufacturer, supplies wholesale alumina conical crucibles, offering both standard stock for fast delivery and custom machining based on drawings or samples.

What Our Customers Say About Alumina Conical Crucible

• ⭐️⭐️⭐️⭐️⭐️
  “The alumina conical crucible with vented lid kept our ash runs cleaner and reduced re-weigh repeats over a semester.”
  — Dr. M. Keller, Lab Manager, Northfield Institute
• ⭐️⭐️⭐️⭐️⭐️
  “Alumina conical crucible with tight ID tolerance matched our lid set; pour-out is smoother than our previous flat-form vessels.”
  — S. Ortega, QA Supervisor, Crown Materials
• ⭐️⭐️⭐️⭐️⭐️
  “Switched from graphite to high-purity alumina conical crucible to avoid carbon pickup in alloy trials; results stabilized.”
  -- D. Weber, R&D Engineer, AlloyTech Europe
• ⭐️⭐️⭐️⭐️⭐️
  “With controlled ≤5 °C/min ramps, our heavy-wall conical cups have survived months of cycling.”
  -- R. Pang, Process Engineer, Meridian Lab