Sciencemadness Discussion Board - Kitty Litter as a Source of Silica Gel?

Kitty Litter as a Source of Silica Gel?

MagicJigPipe - 25-11-2007 at 05:07

I've often wondered if this was a cheap, viable method of obtaining silica gel and if so is it's purity acceptable for most/some drying methods in chemistry? Of course I wouldn't mix it directly with chemicals as I'm not sure of the purity but I don't see why it wouldn't work as a renewable drying agent for drying tubes, arrays etc...

And of course I'm talking about the "kitty crystals" not the clay kind.

not_important - 25-11-2007 at 14:13

My previous reply got zapped by whatever is happening with the hosting, so here it is again

http://householdproducts.nlm.nih.gov/cgi-bin/household/brand...

reports Fresh Step Crystals Cat Litter as being 100% silica gel.

Magpie - 25-11-2007 at 14:13

I can't comment on kitty litter. But as someone else has mentioned on this forum the craft shops have silica gel for reasonable prices. It is sold for drying flowers, leaves, etc.

not_important - 25-11-2007 at 14:24

Quote:

Originally posted by Magpie
I can't comment on kitty litter. But as someone else has mentioned on this forum the craft shops have silica gel for reasonable prices. It is sold for drying flowers, leaves, etc.

Actually I think that was me as well. Always on the lookout for OTC lab supplies.

MagicJigPipe - 25-11-2007 at 14:43

I wonder if they have it in the flower section of wal-mart. However, if the kitty litter is indeed 100% silica gel then that would be the best source, I think, because it's ~$8 for a few pounds. That would last me a year.

UnintentionalChaos - 25-11-2007 at 17:01

I have a canister of the flower drying silica gel from god-knows-where years ago and some of the material has been doped with cobalt chloride so you know when it's drying ability is exhausted.

carbonic - 25-2-2008 at 09:46

you can make your own silica gel by acidifying sodium metasilicate, available as concrete cleaner (and sometimes marked as TSP - triple super phosphate - check the msds). The gelling is fun to watch and after that you just dehydrate and fire it into any shape you want.

bfesser - 25-2-2008 at 09:55

But wouldn't it be cheaper to just buy the kitty litter than to buy concrete cleaner and acid?

Sauron - 25-2-2008 at 10:28

Silica gel is available from many non-chemical suppliers and in many grades, mesh sizes, etc. for a great variety of purposes, non laboratory related as well as lab specific. The non-lab related applications vendors are unlikely to be subject to any sort of restrictions other than minimum qty purchases etc.

So I really fail to see why anyone needs to much around with kitty litter which is likely to contain ingedients other than silica gel, which would have to be removed.

MagicJigPipe - 25-2-2008 at 15:55

There are kitty litters that seem to be nothing but silica gel (from what I can gather).

That's what I was talking about and I did not mean trying to remove silica gel from standard kitty litter compositions. Just to clear that up.

EDIT
By the way, as far as local OTC sources go. The flower drying "compound" at Hobby Lobby is great. It seems to be clean with no dust and about 1/10 "beads" is doped with cobalt chloride which, of course, turns pink when hydrated.

[Edited on 25-2-2008 by MagicJigPipe]

carbonic - 26-2-2008 at 16:45

yeah, might be easier to just get it from kitty litter if it's fragrance-free. i was under the assumption that kitty litter would probably contain all sorts of other junk, and would not be pure.

btw - the main advantage of making it yourself from scratch with metasilicate and acid is that you can dope it with metals, for trying all those cool experiments that call for boron, iron, copper, zinc, cobalt in silica gel matrix. That's how it's done there, add a metal salt to the metasilicate solution and acidify to gel it up with the metal embedded into the silica matrix - it's not just metal salt onto pre-made silica, that would wash off.

solo - 26-2-2008 at 17:02

Bob's sand for kitty litter is 100% polysilicate....................solo

PHILOU Zrealone - 27-2-2008 at 07:10

The grey kitty litter is not the silica gel...the transparent glassy ones are.

The silica gel variety is expensiver by a factor 5-10...

Here in Belgium:
Grey = 2-4€ / 5-10kg
Silica = 5-8€ / 3-5kg

bio2 - 27-2-2008 at 07:30

I have a bag of zeolite clay cat litter that actually has an elemental assay on the label.

Magpie - 17-4-2015 at 13:52

Be careful about what type of kitty litter you use for waste disposal. It seems that WIPP used an organic based ("green") type that reacted with nitrates in their radioactive waste. Result: the container popped its lid contaminating the area with radioactive waste. The WIPP has been shutdown and the costs for cleanup will be horrendous.

http://www.livescience.com/50286-kitty-litter-to-blame-for-n...

Mesa - 17-4-2015 at 17:20

Quote: Originally posted by carbonic

yeah, might be easier to just get it from kitty litter if it's fragrance-free. i was under the assumption that kitty litter would probably contain all sorts of other junk, and would not be pure.

btw - the main advantage of making it yourself from scratch with metasilicate and acid is that you can dope it with metals, for trying all those cool experiments that call for boron, iron, copper, zinc, cobalt in silica gel matrix. That's how it's done there, add a metal salt to the metasilicate solution and acidify to gel it up with the metal embedded into the silica matrix - it's not just metal salt onto pre-made silica, that would wash off.

The problem is the difficulty in producing anything that approaches the surface area to volume ratio in commercially produced products in an amateur setting. I'd expect it to take a bit of refining of the procedure to get something that isn't significantly inferior.

violet sin - 18-4-2015 at 03:04

@ MagicJigPipe from way up thread: the only thing I have found in the flower section of wallmart is the "water cyrstals" in a can. they do indeed take up water, but it is a potassium methacrilate(sp?) like in diapers. they swell when full of water, a LOT. also much cheaper on ebay, 3lbs for 22$US as opposed to 12$ for 8oz. the ones I got are small, maybe an 1/8" size. when loaded with water, a chunk roughly the size of a US quarter if it was a sphere instead of flat.
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TSP, almost always sodium metasilicate( stated on label), but rarely the actual trisodium phosphate in a green(?) box I think, is usually around 4.99$/lb, and acid roughly 10$ gal for muriatic. so about 15$/lb rough estimate, but don't forget about all the time and effort to react, clean and bake solid the material. the stuff offered by Loptr in the 3Å molecular sieves presale thread was 15$/lb + shipping with no work involved for the color indicating pellets.

I would consider using the kitty litter as an absorbent of NO2 though, hell ya. I think the subject was brought to light most recently in Aga's chalenge for nitric acid, and I had also seen it in some other threads and patents as well. absorbing the low% NO2 over a period of time, and after heating, released in a controlled manner. genius, and I want to try it on the HV arc I was working on. if it can turn the inside of a mason jar rusty red in a short period of time, then I could do a few batches quickly and liberate the NO2 in one go. over and over again

Mesa - 18-4-2015 at 05:24

It's not directly related to the thread, but kinda related to the last post:
Does anyone know if the specific filter media's you get in fish/aquarium shops as "nitrate a(d)bsorbers" function as a catalyst(i.e. producing 2 N2+ O2) or by adsorbing NO2- onto the zeolite/ceramic pieces?

I get the feeling I'm showing off some embarrassing knowledge gap in some fundemental aspect of chemistry by asking but cursory googling gave no answers.

[Edited on 18-4-2015 by Mesa]

Dr.Bob - 18-4-2015 at 06:54

For use in drying tubes, any source of silica gel might work pretty well, especially if you can gather a bunch of the packets use for drying things in shipments, as they are more likely the right pore size to absorb water, although they are likely not dry after a few months on a frieghter in the ocean. But if you combined a bunch or some kitty litter type, and dried it well, it would be fine for drying things. I will not work well for chromatography or other chemistry reactions, as the surface area will be way too small. And many craft/hobby shops do sell CaCl2 or silica gel for flower drying as well.

macckone - 18-4-2015 at 09:36

Silica gel for flowers $15.99 for 5 lbs.

http://www.michaels.com/activa-flower-drying-art-silica-gel/...

Heat well before using to remove any stray volatiles.
Not appropriate for chromatography but useful for drying solvents.
In powdered form (use a respirator) also useful for filtering.

http://www.amazon.com/Diatomaceous-Earth-Food-Grade-10/dp/B0...

Also good for filtering and when heat dried will absorb a fair amount of water but not nearly as good as the michael's product.