HI....

I just recently did some drying of solvents using epsom salts... and i noted some things, so i wanted to ask some questions..

1. Is it normal that acetone take on a yellowish tint once dried with the anhydrous epsom?

2. Can i use epsom salts ad-infinitum if i just keep oven drying them???

3. Can FASA be used on ANY petro SOLVENT???

I've noticed a yellowing of the solvent on a few occasions.
If your epsom salts went grey that may be the cause.
The coloration dissappeared when i filtered through a cotton ball.

& yes you can continually re-use them through drying. Be extremely careful & make sure all the acetone has evapped before oven drying again. Leave them to dry a few days spread out on a tray.

I'd look around & post here if you can't find info on fasa with a different solvent.
Xylene & tolulene can be salted out via fasa, naphtha i hear messes things up.

Not FASA directly, because FASA exploits fumaric acid solubility in acetone. Oxalalic acid in anhydrous diethyl ether is another method.

What needs to be observed is that not all acid salts will crystallize well, and the acids that do work need to be paired with a solvent that has some degree of limited solubility with that acid.

do the xylene or toluene need to be dried with epsom too??

Nope cause water is not miscible with toluene/xylene

That does not mean water isn't present. Yes, dry your xylene or whatever you're using. DRY IT.

If buying Epsom Salt in a granular form should it be ground to a powder in a blender before dried in an oven due to picking up H2o better?

just microwave it for about 5 minutes.

Granular does not need to be crushed. Further powdering won't hurt anything & if you feel you need to i'd go for it.
If what you had was crystal epsom salts, you'd need to powder, although it does seem to melt into a goop when heated & then dry to a hard powdery chunk regardless of the size of the crystal/granule pieces.

Any suggestions for containers to do this in?
I've tried microwaving MgSO4 & using a pot on the stove. Obviously you can't put tin foil in a microwave. Without something to sit on, the MgSO4 forms one incredibly hard, solid chunk that is nearly impossible to remove from the container without dissolving in water.

I'd like to be able to microwave though since it saves so much time, so a method that prevents a huge rock solid chunk sticking to the bowl would provide extremely valuable

i put it in glass dram vials. any glass container would suffice.

i used to dry it in the oven @ 425 for 2 hrs. the microwave cuts the time down immensely. 5 to 10 mins dries it to a solid white cake. just wipe any condensed water on the sides of the container with a towel

I have some 8ml amber dram vials. The contsiners are far too small to hold the amount of material i use. I do tend to go overboard though. 100g MgSO4 dried per 500ml acetone.

I have a glass mixing bowl that would work fine though.
You don't run into problems forming hard chunks with glass?

yea, they form chunks, but those also break up readily. at that point, grinding them is optional.
i use the solid white slabs in my vac desiccator.

Thanks for the tip

Any input on how long is neccessary for the epsom salts to do their work on the solvent?
Generally i leave it sit for 24hrs but i have a feeling that much time is not neccessary.

I don't have alot of free time & salting out always gets split up over the course of a few days because of it.

a few minutes. i usually let it sit 4-5 mins

Get a silicone baking mold for drying magnesium sulfate and other dessicating agents. You'll never have to scrape or chisel the crusts off the container again.

+1 for this