[delchod]

Hi,

I am not a chemistry knowledgeable person in general but researching brought me to this forum and decided to give it a go. The question might be out of topic and please excuse me if it is, it is concerning research I am doing on a behalf of my company  and really would appreciate any help. So.. the question.

Is it possible to turn Crude Iodine Crystals into Iodine prills? How complicated this process could be with regards to equipment?
Crude Iodine in crystal form is usually with lower level of purity 99.1%-99.5% where the prilled Iodine comes at 99.8%. i understand that crystallization process in manufacturing this chemical would allow some impurities to be trapped in the crystals and hence the lower purity level. Any possible ways of further purify the Iodine which is already produced in crystal form and make it prilled?

Many Thanks   

[Corribus]

Iodine sublimates very readily by gentle heating under reduced pressure, and so this is a convenient method of purification. Just make sure you take necessary safety precautions.

https://eic.rsc.org/exhibition-chemistry/sublime-iodine/2000060.article

[delchod]

Iodine sublimates very readily by gentle heating under reduced pressure, and so this is a convenient method of purification. Just make sure you take necessary safety precautions.

https://eic.rsc.org/exhibition-chemistry/sublime-iodine/2000060.article

Hi,
Thanks for the reply. I have seen this process before, and it most definitely work with very small amounts of the substance but imagine this process applied to 20mt  My question is probably not formulated correctly, as mentioned I am not very knowledgeable about chemistry processes, however it was more about the technology implementation in the chemical process where crude iodine crystal is turned (if this is even possible) into prilled Iodine and purified as a consequence of this process. I know for example Chilean manufacturers turn pure liquid iodine into prills processing it with some sort of gas, but this would not apply to crystal I can imagine, unless is liquified before that? 

[Enthalpy]

Sublimation shouldn't be a worry with 20t. If you start from a powder and heat a bit more than the absolute minimum, you should get an interesting pace. Or boil it if you prefer.

Precisely because iodine sublimes and few substances do, it is a natural way to purify it.

Melting and solidifying does purify substances...
- Iodine has 12kPa vapour pressure at the melting point, so your pot doesn't really need to resist pressure, but it MUST contain the dangerous iodine vapour.
- Molten iodine is almost evaporated. You apparatus must avoid the condensation of the vapour at the wrong places, with walls hot enough and so on.
- Purification occurs only if the impurities are rejected elsewhere during the solidification. This may demand a slow solidification, well oriented, and so on.