Author Topic: Celite  (Read 6536 times)

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Chromic

  • Guest
Celite
« on: November 30, 2002, 03:12:00 AM »
I love this stuff. I've read tons about it in the search engine especialy from Rhodium. I wanted to give one piece of advice for preparing the filter.

Take the buchner, and place the filter paper on it. Wet it with a few mls of solvent (eg water). Then take a teaspoon to a tablespoon of celite (not much is needed, often less is more) and put it into a beaker with a ten to twenty mls of solvent. Turn on the vacuum, swirl the beaker around, then suck it through. You'll get a perfect uniform depth of celite each and every time.

This stuff is cheap, usually $2-5/kg. I highly recommend anyone who runs into something that takes years to filter. It will speed it up to only take minutes. I can't believe I ignored the value of it for so long.

Rhodium

  • Guest
CeliteRocks! [Filter Aid / Emulsion Elimination ]
« Reply #1 on: November 30, 2002, 05:06:00 AM »
Yes, Celite (diatomaceous earth) is one of the organic chemist's best friends. It not only speeds up otherwise impossible filtrations, it also helps you filter out things that would go right through a fritted glass funnel or normal filter paper - something that immediately comes to mind is activated carbon (both decolorizing carbon, as well as for example Pd/C). If you have tried to filter off activated carbon using standard methods, you know what I mean - it is impossible to get rid of the last traces of suspended carbon particles in your filtrate.

Another thing that makes Celite invaluable is its ability to break any kind of emulsion you have managed to get in your sepfunnel. Just filter both phases and the emulsion inbetween through ~1cm of Celite on a buchner at the pump (don't forget to wash the filter cake with a little suitable solvent afterwards), and when the liquid collects in the filter flask, it will always be in two layers again. You will also have removed many of the colloidal particles which helped the emulsion form in the first place, so during subsequent extractions you are much less likely to get an emulsion again.

hCiLdOdUeDn

  • Guest
Awesome, Celite DOES rock!!
« Reply #2 on: November 30, 2002, 05:50:00 AM »
Awesome, Celite DOES rock!!

Sink or SWIM

BlingBling

  • Guest
I feel left out
« Reply #3 on: November 30, 2002, 05:56:00 AM »
Where do you get it? I always thought it was those Celite scrub pads.

Semtexium

  • Guest
Chem supplier, but is also OTC...
« Reply #4 on: November 30, 2002, 06:19:00 AM »
One of the simplest places is a chem supplier, not suspicious at all, but often times is expensive, right Rhod...?  Diatomaceous earth can be found OTC at garden supply places, CHEAP, I mean 50lbs would be under $20 from what I remember(I have a 2.5kg pail of the stuff from a chem-hut and haven't used any of it yet so I've had no need for more)...  It's an organic pesticide, used from crops to mixing it in with Animal feed to swimming pool filters...

::)  ;D  :)  :P  ;)     Mean People Suck     ;)  :P  :)  ;D  ::)

BlingBling

  • Guest
something lite
« Reply #5 on: November 30, 2002, 06:24:00 AM »
Is it the white rocky substance used to top off a vermiculite cake in mush cult? I can't think of the name of that stuff.. If so, they sell it at wallys, next to the vermiculite. It's like made of volcanic matter.

Found a pic of a celite bag on google

Chromic

  • Guest
Celite rocks? :)
« Reply #6 on: November 30, 2002, 08:50:00 AM »
Instead of decanting off ethanol repeatedly with an Al/Hg (a la Osmium) or basifying it (a la Ritter / Methyl Man), has anyone tried filtering the entire post reaction mixture with celite? Then distilling the ethanol to reuse it? It seems so simple and efficient.

Rhodium

  • Guest
celite4ever
« Reply #7 on: November 30, 2002, 10:39:00 AM »
Oh yes, most certainly! I couldn't imagine working with the sludges after Al/Hg or LAH reductions without having access to Celite. The beauty of recovering the solvent from Al/Hg aminations through distillation after filtration is that it contains a whole lot of methylamine freebase, so that you don't need to add as much in your next run. Recycling listed chemicals is always a nice thing to do.

Osmium

  • Guest
There are many types of celite available from ...
« Reply #8 on: November 30, 2002, 01:53:00 PM »
There are many types of celite available from chem suppliers. Which one to use?
Never seen it OTC.

I'm not fat just horizontally disproportionate.

Rhodium

  • Guest
Os: The cheapest. The more expensive brands are ...
« Reply #9 on: November 30, 2002, 02:50:00 PM »
Os: The cheapest. The more expensive brands are for analytical work.

Osmium

  • Guest
They seem to differ in many more respects than ...
« Reply #10 on: November 30, 2002, 02:56:00 PM »
They seem to differ in many more respects than just extractable inorganics! Like surface area, density etc. The instructions by the manufacturer I once saw gave examples for all kinds of different filtrations, e.g. yeasts in beer manufacture, different analytic filtrations etc, and recommended different kinds of Celite for different filtration problems.

I'm not fat just horizontally disproportionate.

TheBlindGenius

  • Guest
For example Pd/C Pd/C is expensive but reusable, ...
« Reply #11 on: November 30, 2002, 03:08:00 PM »
For example Pd/C

Pd/C is expensive but reusable, for the most part, although it does lose some of its activity each time you use it right?  Is there any way to recover it from Celite?  Or does swim have to just use a regular Buchner if he wants to reuse his Pd/C?  If so, what is the best filter paper for this?  They make so many, even each brand has dozens of numbers and materials.

PolytheneSam

  • Guest
diatomaceous earth
« Reply #12 on: November 30, 2002, 04:42:00 PM »

Post 217504

(PolytheneSam: "Re: promotors of Urushibara ??", Novel Discourse)

Post 211468

(PolytheneSam: "Re: promotors of Urushibara ??", Novel Discourse)

Post 182801 (missing)

(PolytheneSam: "Re: Nickel vs Pd", Chemistry Discourse)

ebay?

http://www.geocities.com/dritte123/PSPF.html


The hardest thing to explain is the obvious

terbium

  • Guest
Swimming pool filters.
« Reply #13 on: November 30, 2002, 04:54:00 PM »
Never seen it OTC.
In the U.S. it is available in large bags from most any hardware or swimming pool supply store. It is used in the pool filters which have a canvas bag that is then coated with celite by adding a scoop of it to the filter intake.


Baseline Does Not Exist.

Chromic

  • Guest
Sweet!
« Reply #14 on: November 30, 2002, 05:47:00 PM »
Well this is an easy way to save adding many grams of NaOH to the alcohol to basify... I'll try it next time. I'm surprised no one has pushed this method.

Rhodium

  • Guest
how to filter Pd/C using celite
« Reply #15 on: November 30, 2002, 06:18:00 PM »
BlindGenius: If you use a very small fritted glass funnel like the one below (they are about 5 cm across), you will be able to remove your catalyst for re-use without any contamination. But - some of the small carbon particles will penetrate the glass frit and get lodged in there forever, making it look somewhat ugly. If you would cover the bottom of that funnel with 5 millimeters of celite, and pour your solution containing suspended Pd/C onto it very carefully, it will stay in place, and after you are done with the filtration, you will have two layers of solids in the funnel, the Pd/C on top of the celite. Now you just take a small spatula and carefully remove the catalyst layer (and put it in a vial half-full with water) and next to no celite will be carried over. And even if a few grains would carry over, that doesn't really matter, as celite is completely inert, and will have no effect on your next hydrogenation reaction.


Organikum

  • Guest
recovering catalyst
« Reply #16 on: November 30, 2002, 06:34:00 PM »
If your catalyst is for example 30 mikrometer standard (or the particels of the activated carbon you used to make it) you apply an filter (or fritte) with about 20 mikrometer pores. Of course many particels of the catalyst have broken down and got smaller, very much smaller, so after filtering you will still see a lot of catalyst left in the solvent. Refilter it several times through the same filter used before, so by principle the catalyst filters itself.

Thus spoken by DEGUSSA in their specifications on noble metal catalysts. Prior they advise centrifugation if any possible.

ORGY

now or never

terbium

  • Guest
Glass Fiber filters.
« Reply #17 on: November 30, 2002, 07:42:00 PM »
What I find to be far superior to glass frit or celite are the glass fiber filters made by Whatman. They have very rapid filtration even when filtering fine sludge and retain particles down into the 1-2 micron range. They are a bit pricey, about $35.00 for a package of 100 7.0 cm filters.

http://www.whatman.com/products/analytical/labfiltration/a_pd_labfil_007.html


http://www.whatman.com/tech_support/tools/bla_tools_004.html


http://www.whatman.com/index2.html



Baseline Does Not Exist.

Rhodium

  • Guest
what man?
« Reply #18 on: November 30, 2002, 08:50:00 PM »
terbium: Have you been able to filter precipitated metal (hydr)oxides using them? I bought Whatman glass-fiber filters like the ones above after some salesperson at the local chem supply said that they would be perfect as a "no-holdup" alternative to celite for removing precipitated TiO2/Ti(OH)2 from aqueous solutions, and when trying to put them to use I soon noticed that they aren't that different from paper filters, besides being inert and having exceptional wet-strength (is that a word?)

terbium

  • Guest
Probably celite would be better for that.
« Reply #19 on: November 30, 2002, 11:04:00 PM »
I can't remember the worst sludge that I have filtered with glass fiber filters. Seems I would have to agree that for a really fine sludge a deep bed of celite might be better. For most other cases, with slightly less intractable precipitates, I would still say that the glass fibers are far superior to paper - faster filtering, much slower to clog and better retention of fine particles.

Baseline Does Not Exist.