Corundum Tube Manufacturer: Detailed Features and Cleaning Methods of Corundum Crucibles

If we talk about crucibles, I wonder how many people know about them. In fact, crucibles are an important part of chemical instruments. They are containers for melting and refining metal liquids, heating and reacting solids and liquids, and are the basis for ensuring that chemical reactions proceed smoothly. However, there are many types of crucibles, including iron, quartz, graphite, and corundum, etc. Actually, today Corundum tube The manufacturer wants to tell you about corundum crucibles.

　 　I. Characteristics of corundum crucibles

　　1. Crucibles with an alumina content exceeding 95% are called corundum crucibles.

　　2. Composed of porous electrofused alumina, it has high strength and is refractory.

　　3. Suitable for melting samples using weakly alkaline substances such as anhydrous Na2C03 as a flux, but not suitable for strongly alkaline substances such as Na2O2, NaOH and acidic substances (such as K2S2O7, etc.).

　　II. Indicators

　 　Corundum tube The manufacturer stated that alumina crucibles and corundum crucibles with non-expanding ceramic crucibles are a new generation of products in China following clay, cordierite, timely, and coated crucibles. Non-expanding ceramic crucibles. Their service life and effect are comparable to Corning imports from the United States, and they are highly praised by users for their long service life and low consumption. They have an ultra-low expansion coefficient and high thermal shock stability.

　　III. Cleaning methods

　　1. Acid pickling: Generally, it is soaked in nitric acid for a long time; rinse with water again.

　　2. Drying, slowly heating to 800 in a high-temperature furnace and maintaining for 6 hours.

　　3. After cooling, it can be used.

　　4. Remove impurities and convert insoluble substances into soluble nitrates to remove them.

　　5. Remove trace nitrates (thermal decomposition method): Note that the heating rate must not be fast, otherwise it will peel off (explosion damage).

　 Corundum tube The manufacturer said that it has a very good usage method. The following is the usage method:

　　When solids need to be heated with a high fire, a crucible should be used. The crucible lid is usually placed at an angle to prevent the heated object from jumping out and to allow air to freely enter and exit for possible oxidation reactions. Corundum tube The manufacturer stated that because the bottom of the crucible is small, it generally needs to be placed on a clay triangle for direct heating. It can be placed upright or obliquely on an iron tripod, or it can be placed according to experimental needs. After heating, the crucible should not be immediately placed on a cold metal table to avoid cracking due to rapid cooling. Do not immediately place it on a wooden table to avoid burning the table or causing a fire. The correct way is to let it cool naturally on a tripod or cool slowly on an asbestos net.

Main uses:

　　(1) Evaporation, concentration or crystallization of solutions

　　(2) Burning solid substances

　　Precautions for use:

　　(1) It can be heated directly, but it cannot be quenched after heating, and crucible tongs can be used to remove it.

　　(2) Stir during evaporation; when it is almost dry, evaporate with the remaining heat.

　 The above is the introduction of the characteristics, indicators, and cleaning methods of corundum crucibles by the corundum tube manufacturer.