Method for removing graphite crucible slag

Graphite crucible has the characteristics of large volume density, high temperature resistance, fast heat transfer, acid and alkali corrosion resistance, high temperature strength, high oxidation resistance, but in the melting process, the additives and impurities in the metal solution will form slag, attached to the crucible wall, because the slag contains additives, will corrode the crucible wall, so we must adhere to the slag once a day. So what are the removal methods?

Graphite crucible manufacturers said that when the slag has not yet solidified, special tools should be used in time to remove it. The solidified slag will be difficult to remove, and care should be taken when cleaning to avoid scratching the wall of the crucible

When the multi-layer slag solidifies and remains on the wall of the crucible, it will corrode the crucible, affect the thermal conductivity of the crucible, and cause the crucible to crack during heating expansion, thus shortening the service life of the crucible

We can use hydrochloric acid to clean, most of them can be dissolved, some residues contain carbon components, the use of hydrochloric acid is insoluble, then you can use nitric acid to clean, because nitric acid has a strong oxidation, in the cleaning can also be properly heated

For those substances that are still difficult to remove, they can be boiled in dilute hydrochloric acid or dilute nitric acid, taking care that the hydrochloric acid used must not contain nitric acid, nitrate, halogen and other oxidants. If dilute nitric acid cannot be washed, it is cleaned with potassium pyrosulfate, sodium carbonate or borax melt

The graphite crucible needs to be kept clean, both inside and outside to be bright, after a long time of burning, the appearance of the crucible may become dark, and the crucible is fragile, after a long time into the interior it will break, so the need to remove the unclean material, if there is still a stain or black surface, then the fine sand without a sharp edge through the screen, gently rub with water to restore the surface luster