Alumina Arc-Shaped Crucible Without Lid, 99% High Purity, High Temperature Resistant, Multiple Sizes 3ml - 5000ml, Customizable, Corundum Ceramic Cup for Muffle Furnace, Tube Furnace, Laboratory Sintering, Ashing, Melting

Key Features
✅ High Purity Material: Made of 99% alumina (corundum), low impurity content, no pollution to samples.
✅ Ultra High Temperature Resistance: Continuous working temp 1600℃, peak instant temp up to 1750℃, stable performance under extreme high temperature.
✅ Excellent Chemical Stability: Acid and alkali resistant, corrosion resistant, inert to most chemical reagents and molten samples.
✅ Arc-Shaped Open Design: No lid, easy loading, discharging and visual observation of samples.
✅ Outstanding thermal shock resistance, anti-cracking amid drastic temperature fluctuation.
✅ Smooth & Dense Surface: Compact structure, low water absorption, not easy to crack or deform after long-term heating.
✅ Wide Compatibility: Cylindrical flat bottom design, stably placed inside muffle/tube furnaces. Standard size fits most laboratory muffle furnaces, tube furnaces and high-temperature heating equipment.
✅ Customizable: Various standard sizes in stock, custom dimension crucibles are acceptable.

Multi Purpose & Widely Applicable
- Laboratory high-temperature sintering, annealing and heat treatment
- Sample ashing, carbon residue testing and gravimetric analysis
- Material science research, chemical experiments and mineral testing
- High-temperature calcination and melting of powder, metal and non-metal samples
- University labs, industrial quality inspection and scientific research institutions

Notes / Precautions：
- Sintering Shrinkage & Color Notice: 99% alumina products undergo obvious dimensional change during sintering. High‑purity 99% alumina crucibles tend to be yellowish in color. If strict dimensional tolerance is required, please contact customer service for accurate dimension data before ordering.
- Controlled Heating & Cooling Rate: Avoid rapid temperature rise and fall to prevent cracking. Heating rate ≤5℃/min below 1200℃; ≤4℃/min above 1200℃.
- Prohibited Direct Flame Heating: Do not heat directly with spray guns, alcohol lamps or open flames, uneven heating will cause rupture.
- Pre‑drying Required: Dry the crucible in a 105℃ oven for 2 hours before first use to remove internal moisture.
- Usage Restriction: Do not burn pure carbon powder, iron powder, aluminum powder and other active metal powders for a long time, which will damage the crucible surface.
- Placement Tip: It is recommended to pad the bottom of the crucible during furnace use to avoid direct contact with the furnace bottom for uniform heating.
- Natural Cooling: Take out the crucible only after the furnace temperature drops to room temperature to avoid thermal shock damage.