[3vo]

Hi guys,

Can anyone explain to me please how would I use solubility curves in separating a mixture of salt and gravel to prepare pure salt crystals?

I initially assumed to add water to the mixture and stir until all the salt had dissolved and then separate the mixture using a sive. Next I would slowly heat the brine mixture until all the water had evaporated producing the salt crystals.

But I dont know if this is the best method? Would the salt be considered pure crystal? And more importantly how would I incorporate the solubility curve in this process?

Thanks in advance.

[curiouscat]

Sounds good to me.

If Freestyle solutions are ok just tumble em around for an hour. Salt would be crushed fine. Sieve & be done.

[3vo]

Thanks for the reply.

I was informed that I must incorporate solubility curve into my methodology. Any ideas on how I could do this? or what additional benefit it would provide?

[magician4]

I suppose i know what they want you to do:

usually,
- most "salts" are better soluble in hot water than in cold water (  solubility curve)
- even seemingly insoluble salts ("gravel") are at least soluble in traces

therefore,
- by extracting the gravel / salt  mixture with as little as possible hot water, just enough to dissolve all of the salt in it
- resulting in a brine rich in "salt" AND low in "gravel"
- and cooling that down, i.e. "oversaturating" it with respect to "salt"
- you'll gain pure, recrystallized salt upon cooling this brine, with a saturated brine (hopefully) incorporating all impurities (that are not oversaturated) as a liquid phase that can be separated


so much for theory

in reality, the solubility of common household salt does next to not change with temperature

... and therefore, this whole procedure won't work


regards

Ingo

[curiouscat]

in reality, the solubility of common household salt does next to not change with temperature

....and gravel is worse. You'd need real damn hot to get gravel to solublize at all.