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Re-acidify from dirty naphtha pull? STB

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eternal_symbiote

Rising Star
Merits
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Okay, bear with me here... But couldn't one take an acidic solution to the piss-yellow naphtha from your good old STB and just catch all of the DMT, re-basify, then re-extract in order to basically catch the goodies from the pull naphtha and just basically re-pull, lather, rinse repeat?

It feels like, to me, that that would save quite a lot of heartache in the freeze-precipitation stage where the DMT is mostly suspended with the oil that's hell to catch with a coffee-filter?

I mean it seems like it would work, and I fail to see why it wouldn't, because you can clean the dirty DMT by re-dissolving in clean naphtha, and catching it out with acid... you get the picture. Wouldn't it just be a better idea to skip the whole charade at the end and do it in the middle?
 
cyb said:
This is called 'Back Salting' and is fine to do.

But what makes you think that yellow spice is 'dirty'...it's not...often times it's preferable.

Oh I'm fine with yellow spice. It's the fact that with acacia it seems to be un-necessiarily difficult to freeze-precipiate anything actually crystalline, and when it comes out onto the filter, it's essentially just goo. Goo's fine, too, but I just want crystalization to occur because it makes my life a lot easier with my limited equipment.
 
Also, would turpentine be an acceptible defatting solvent? I mean real gum turpentine, not TRPS. I really should have obtained some xylene as well but I was a bit short that day. I have the better part of a half-gallon of the stuff just lying in want of use, but I fear that turpentine might do more harm than good...
 
Just for defatting it is probably okay, it should even have better resin-dissolving properties than naphta-derived turps.

I wouldn't use it as a non-polar extraction solvent. Pine tree turpentine contains mostly terpenes with double bonds that easily oxidize and react. It is propbably more toxic than the simple alkanes in naphta. It is also much less volatile than light naphta, making it more difficult to dry the final product.
 
I don't know about turpentine but for xylene i read (somewhere at nexus, sorry no source) it's not good to use for defatting cause even in acid solution it can pick up some of the magic.


Edit : ok, i should not trust my memory, a quick search in the wiki showed me you can use xylene (even better than naphta).
 
Back salting is a great way to remove certain impurities, but it won't do much to remove the NMT that creates the "gooey" end product. Recystallizing or precipitating with dry ice are the most effective ways to remove NMT and yield crystals, and neither is "unnecessarily difficult". I would even say that recrystallizing is significantly less difficult than back salting, rebasifying, and repulling; not to mention the fact that it would be much more effective.

Defatting will not remove NMT either, and it is really unnecessary when extracting from Acacia confusa.
 
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