yushen graphite crucible
Because graphite crucible has the characteristics of large bulk density, high temperature resistance, fast heat transfer, acid and alkali corrosion resistance, high temperature strength and high oxidation resistance, it is inevitable to prevent corrosive substances during use. Although graphite crucible has the ability to resist acid and alkali, it is troublesome for the refining of individual raw materials after the use of antimony.
The primary task of cleaning graphite crucibles is to clean out the chemicals in the crucible and then clean them. We need to decide what to use according to what is left in the graphite crucible. Generally, the deposit on the graphite crucible is inorganic. After the combustion, we can use hydrochloric acid for cleaning. Most of them are soluble. Some residues containing carbon are insoluble in hydrochloric acid. At this time, nitric acid can be used for cleaning because nitric acid has strong oxidation. Sexuality can also be heated properly during cleaning.
For those substances that are cleaned, they can be boiled in dilute hydrochloric acid or dilute nitric acid. Note that the hydrochloric acid used should not contain nitric acid, nitrates, halogens, etc. to the oxidant. If the dilute nitric acid is not cleaned, it is cleaned with potassium pyrosulfate, sodium carbonate or borax.
The graphite crucible needs to be kept clean, and the inside and the outside should be bright. After a long time of burning, the surface of the crucible may be completely dull, and it will penetrate into the interior for a long time, causing the crucible to be fragile, so it is necessary to know the uncleanness. If there are still five points or the surface is black, use a fine sand with no sharp edges and corners through 100 mesh, gently rub with water to make the surface regain luster.