100*20*20mm 22ml Professional Melting Square Quartz Crucible, 1600°C Working Temperature, Preferred for Induction Furnaces

Alumina Crucible User Manual

I. Product Introduction

Alumina crucibles are made of high-purity aluminum oxide (Al₂O₃), typically containing over 95% alumina content. They are suitable for various laboratory and industrial heat treatment applications, particularly where high resistance to corrosion and elevated temperatures is required.

II. Key Features

High Temperature Resistance: Alumina crucibles can withstand prolonged exposure to high temperatures, with specific maximum temperature limits depending on the product specifications or manufacturer's instructions.

Chemical Resistance: They exhibit excellent resistance to most acids (except hydrofluoric acid and fluorine compounds) and many alkaline substances, making them ideal for use with weakly alkaline substances like anhydrous Na₂CO₃ as a flux for sample fusion.

Thermal Stability: Alumina crucibles maintain stability during rapid heating or cooling cycles, though sudden quenching should be avoided to minimize thermal stress on the crucible.

III. Applications

Sample Fusion for Analysis: Used in geology, metallurgy, and chemistry for the high-temperature fusion of mineral, metal, ceramic, and other samples prior to compositional analysis.

Material Preparation: Employed in the melting or synthesis of high purity materials or alloys under specific conditions.

Chemical Reactions: Serve as high-temperature reaction vessels for solid-liquid or liquid-liquid reactions.

IV. Usage Guidelines

Heating Method: Alumina crucibles can be directly placed in electric furnaces, muffle furnaces, or other appropriate heating devices, preferably supported by a clay triangle or asbestos mat for even heat distribution. Direct flame heating is not recommended.

Handling Tools: Use dedicated crucible tongs to handle the crucible, avoiding direct contact with hot crucibles to prevent burns.

Flux Selection: Avoid using strongly alkaline substances (e.g., Na₂O₂, NaOH) or acidic substances (e.g., K₂S₂O₇) as fluxes, as they may react with the crucible material, causing damage or affecting sample purity.

Heating & Cooling:

Heat the crucible gradually and uniformly to prevent localized overheating, which may cause internal or external temperature gradients leading to cracking.
Cool the crucible naturally or through programmed cooling; never quench it directly into cold water, as this can induce severe thermal stress resulting in crucible fracture.
Evaporation Operations:

If evaporating in the crucible, continuously stir to promote uniform heating and prevent localized overheating.
Near the end of the evaporation process, allow the residual heat to complete the evaporation to avoid excessive heating that could cause sample splashing or overheating of the crucible.
Cleaning & Storage:

After thorough cooling to room temperature, clean the crucible using deionized water, dilute acid (excluding hydrofluoric acid), or specialized cleaning agents, avoiding abrasive brushes that may scratch the surface.
Store cleaned and dried crucibles properly, keeping them away from substances that might cause chemical reactions and in a dry environment to prevent deliquescence that could affect performance.
V. Safety Precautions

Wear personal protective equipment (such as heat-resistant gloves and safety goggles) during operations, and adhere to laboratory safety regulations.

During high-temperature work, keep flammable and explosive materials well clear of the area, ensuring good ventilation.

For specific experimental conditions or special applications, adjust the operating steps accordingly and consult relevant professional guidance as needed.

VI. Maintenance & Lifespan

Regularly inspect the crucible for signs of cracks, deformation, or other abnormalities. If significant damage is detected, discontinue use and replace with a new crucible. The lifespan of an alumina crucible depends on usage frequency, operating conditions, and maintenance practices, with specific recommendations provided by the manufacturer.

This overview serves as a general guide for using alumina crucibles. Always refer to the detailed user manual accompanying your specific product model and follow laboratory operating protocols. For questions or unique application requirements, consult professionals or equipment suppliers.