How can we use alumina crucible correctly? Nextgen Advanced Materials summarizes it as follows:
When heating solid at high temperature, we must use an alumina crucible. Crucible covers are usually placed properly to prevent the heated solid from jumping out and to allow free passage of air for possible oxidation reactions.
As alumina crucible has a small bottom, we generally need to put it on a triangle mud support to heat it directly by fire. However, the crucible should not be placed on a cold metal table immediately after heating, so as to prevent it from cracking due to rapid cooling. Do not immediately put it on a wooden tabletop, so as to avoid it from burning the tabletop or cause a fire. The correct way of placing a crucible is to leave it on an iron triangulate frame to cool it naturally, or put it on an asbestos net to cool it slowly. Use crucible tongs to move the crucible.
The main usages of crucible are as follows:
(1) solution evaporation, concentration and crystallization
(2) burning solid substance:
Tips for using an alumina crucible:
Alumina crucible can be directly heated, but it cannot be quenched immediately after heating. Use crucible tongs to remove it
Put the crucible heated on the triangle iron support
Stir for evaporation; use residual heat to steam the solution to dry.