Grinding Al foil

[Trenchcoat]

Why does one have to grind the Al foil into nuggets for the MethylMan Al/Hg? Wouldn't it react better if the squares were just put in there flat?
Better loving through chemistry.

[Rhodium]

Eleusis said he used a document shredder.

[baalchemist]

Grinding into nuggetsmakes it easier to mag-stir and it also
'paces' the reaction by not exposing the entire surface area of the foil at once. Otherwise it would turn into an exothermic Al/Hg volcano, not too fun to bathe in that crap.
GODISNOWHERE

[Chromic]

SWIC has just crumped them up with his hands, can be done in 50g batches at once and in bigger runs than a bean grinder. It takes about 3-4hrs to rip up 250g of al foil into 1" pieces, but only maybe 15 minutes to crunch them into little balls (roll the pieces between your hands, and you get nice tight balls formed). It works very effectively. Also, I gotta point out... always, always dissolve the mercury salt in the methanol before adding the foil. That was a silly point of failure a while back, resulted in not much fun being produced.

[noj]

roll half with fingers and half with grinder... the hand processed ones will float and not bog down the stirrer.
Author unknown.

[KrZ]

Flashing.  It's the bomb Al source.  Nice and thick so you can submerse a kg of it per liter, and a sufficient surface area to assure the reaction doesn't get outta hand.  As far as grinding to regulate the reaction, it's exactly the opposite, lower surface area/mass is less violent.  Now while you can't stir magnetically with this stuff, you can do overhead, or just reflux the reaction with a circulating ice/water bath.  You will lose suprisingly little amine and the refluxing provides sufficient circulation.  Bon appetit.

[Chromic]

Definitely, refluxing is wonderful for larger batches if you don't have an overhead stirrer.

[Rhodium]

Could somebody explain the term "flashing" in this context for someone whose native language is not english?

[Buster_Hymen]

I think he's talking about aluminum flashing, which is used in construction of buildings and homes, on roofs, etc. Comes in pre-made shapes, or in roll form:


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[Chromic]

I've had bad experience using thick (~2-3mm) aluminum sheeting. I don't recommend it. Aluminum pie pans are about as thick as I can go before the aluminum amalgam doesn't seem to work well anymore. I wonder if it's just the mercury is getting sloughed off as the reaction proceeds. YMMV as I didn't test this out much after hitting a failure.

[KrZ]

Did you compensate for the reduced rates with increased reaction time chromic?  Aluminum flashing is about as thick as those pie plates but the rolls are cheaper and more manageable.  Also, when you use a very large excess of flashing chips without sufficient water for total Al(OH)3 conversion but with enough for the reduction, the Al(OH)3 will all be on the surface of the chips and you will have something that filters very quickly without trapping any goodies in the so-called Sludge (not present).

[Chromic]

I used small chunks of torn-up aluminum sheet (2-3mm thick is a lot more thick than pie plates which are less than 1mm thick). This stuff could not be rolled up as it's too thick. It sounds like we're talking about two different animals, I guess I misundersand. And yes, I used enough water, stirring, and time (>24h).

[KrZ]

You must be a womanly girly man who cannot shred the puny aluminum.

[Semtexium]

GiRLY MON YEAH!!!  
            Mean People Suck             

[RoundBottom]

a faster way than ripping, is to use a long framers level or long ruler, and an xacto knife/box cutter to cut into strips 1" wide, then use scissors to cut into 1" squares.  do this one strip at a time, otherwise they get stuck together.  just snip over a bowl to catch the squares.

[spric]

A large roll of reynolds heavy duty can be processed in about 10-15 minutes with a heavy duty pair of scissors and a cheap ass blender that you don't mind ruining..  Cut the foil off of the cardboard roll.  Cut that layer of about 100 sheets of foil into squares, about 1-2 inches, and throw them in a blender.  It makes thick chunks, but works quite well.
tweekers have speed weenie

[DiethylEtherMan]

Use a document shredder to shred the al foil....then put in a nice blender to ball (looks like rice) the shit up.

Takes 10-15 tops to bang out 250g of al.

DEM
If some of us were not so far ahead, the rest of you would not be so far behind!

[pimpmaster]

i have only seen flashing containing atleast a little bit of Sn is that bad for someones dreams .
just wondering

[Prdy2GO]

Yes this is the way!!!
Get the heavy duty (Must Be!) renyolds Al foil extra wide. 36" = 28 Grams isent that interesting>?
Rip it length wise and feed it into a cheep paper shreader.
With one hand grab one of the two bunches keep em somewhat stright and cut about every 4" or so into a bowel.
Use a Krups the best for this or a braun coffee grinder and grind lightly not too packed for about 8 seconds. You will see how uniform it looks this way. Doing several 75 sq. Ft rolls at a time this get's it done in a hurry. You dont want to bind or bogg down your equipment to take it easy dont smook the motor on your grinder heck someday you may want to drink some coffee again...
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Hum did you get that?

[Osmium]

1mm or thicker Al is too thick. Reaction will take several days.
0.1-0.3mm Al works very well, and can be cut with regular household scissors.

[Chromic]

Thanx Os, I'm relieved to know that it's not just my bad lab techinque.  

[RoundBottom]

what about the aluminum powder used in pyrotechnics?  i know this would be off the scale for surface area, creating really fast reactions.

ALUMINUM POWDER - (granular) 20 to 200 mesh $7.95/lb
ALUMINUM POWDER - Alcan 7100 (dark pyro aluminum) American dark $12.95/lb

[Trenchcoat]

If one were to use powdered foil and add it very slowly you wouldn't have to worry about some of the aluminum not reacting cuz the nuggets were to tight or whatnot. I'm a chem lackey. Made me wonder, though.
Better loving through chemistry.

[sunlight]

Using too thin aluminium foil, the rxn is not very controlable. Using aluminium powder will be worse, so really it will be good for kitchen pyrothecnics. Or add the Hgl2 to the solution and then put in small portions the powder. Having that the foil works fine, there's no reason to buy powder, IMHO.

[chem_123]

where would a bee get powdered AL?
Don't eat yellow snow!, unless you know it's honey!

[Rhodium]

Pyrochem/fireworks suppliers.

[noj]

Wow, I recall this thread.

Chaque un à son gout

[chem_123]

thanks, also found that some big paint suppliers sell it for addition of a metallic fleck look in paint.
Don't eat yellow snow!, unless you know it's honey!

[MMM]

Scissors can get a bit tiring on flashing (Ouch). If your a lazy wimp like Swim, you could get a paper guilotine. Cut off about a foot (a bit shorter than the blade) cut strips nearly all the way through, the rotate the joined strips through 90 degrees. and cut off the squares.  Swim found this about 5 times faster than scissors. The joining strips were kept aside, and fed through later in groups.

Of course if you like menial tasks , stay with scissors.

Swim found overhead stirring was fine, but did consider making a custom guillotine that would bend each square as it was cut for easier stirring {so they look like /\ instead of --}

MMM


MMM
When the day is bad,and life's a curse
CHEER UP!!! Tomorrow may be Worse!!
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[Vibrating_Lights]

If Al powder is used then is 27.5 gms still the required ammount for a complete reaction?  also it is obvious that the al powder must be amalgamated prior to addition, could water in the solvent possibly eat up the alumnium before it got to the reaction. solvent levels could probably be reduced drasticly with a controlled addition.
VL_

[SiLiCoN7]

Just Tear the stuff up in big pieces and jam your COFFEE GRINDER about 1/3 full and wizz for  10 seconds or so. The Al will bee chewed up good and proper. It is easy, SWIM dose not think it is too critical as long as it is all ground up for stirring.
If you're not talking to your kids about drugs who is?

[ScuzZ]

Isn't it that the foil is rolled into small balls to stop it all reacting at once and creating an inferno?
Something to do with the amount of surface area to acid..

[noj]

I don't believe the surface area can be changed unless it were melted into form. Either way, it will be exposed somewhat. Swim just did an experiment with the Al, in which he took the 1 inch x 12 inch strip and balled it up to the size of a peanut with shell. Did this to all 56 grams and it worked like a dream. Al floats on top and the bar only has to stir the MeOH and precipitate sludge as it forms. It also seemed to react for 4 hours without heat added (It stayed warm so I didn't interfere- exothermic reaction without added heat must mean reaction is still taking place. Will see yields in a few hours.


VL- I think it would have to be experimented abit. Powder will have ALOT more surface area, meaning more Al2O3 per gram of Al.


Everyone falls down. It's how fast you get back up that is important.

[LaBTop]

Like adding the Aluminium powder with a powder addition funnel, into the solution with the HG salt slowly. LT/
WISDOMwillWIN

[SiLiCoN7]

(ScuzZ)It's not scid, the Al is being amalgamated by the mercery salts.
SiLiCoN7 has never had a reaction go out of control. even with finely ground thin foil. It is mostly the rate of addition of the ketone that controls the speed of the reation.
The Earth is 40% quartz crystal....

[chem_123]

SWIM found a place that has Al powder, good price too.  But it's aluminum oxide not al powder can this bee used instead? what aboot the ever so popular t-h-e-r-m-i-t-e...can the aluminum oxide bee used for that?
Don't eat yellow snow!, unless you know it's honey!