KCN via K3(Fe(CN)6) and KOH ?

[simply RED]

The question is extremely simple:
Is the following reaction possible and if yes, what are the optimal conditions for it?

K3(Fe(CN)6) + 3KOH = 6KCN + Fe(OH)3(precipitate)

I have no access to proper conditions to try it...

[Cindor]

In Black Book Companion there is a way to make Potassium Cyanide and that uses Potassium Carbonate and Potassium Ferrocyanide and a furnance, maybe there is your way to go.

[kurtz]

I doubt the answer is so simple. You mention precipitate so I guess you're talking about solutions. I'd think that cyanide is more prone to alkaline hydrolysis than the ferricyanide. Ferricyanide doesn't react at room temperature at a reasonable rate; I've done this - making ferrocyanide in very good yield and purity by adding H2O2 to the mixture.

It seems reasonable to guess that heating in solution ferricyanide with hydroxide or carbonate would give some KCN, some ferrocyanide and cyanate by reaction of the ferricyanide and the KCN, and K formate and ammonia from hydrolysis of KCN.

So I doubt that the "recipe" that you are looking for is out there, even though there are probably a couple of different ways possible to get something. Any guesses would be just that and experimentation is the only way to go.

[Mortifero]

Hello,i found another procedure to make potassium cyanide

>You'll need potassium bicarbonate to make potassium cyanide, or sodium
> bicarbonate (baking soda) to make sodium cyanide. The potassium
> bicarbonate is available from a wide varriety of suppliers. You'll
> need urea or cyanuric acid. Urea is sold as a bulk fertilizer for very
> low prices at hardwear or garden stores, but is hard to find in small
> quanities. It can also be found in instant cold packs (sports) in many
> drug stores (urea and water in the pack, just take out the urea
> pellets ONLY). Cyanuric acid is available at pool and spa stores were
> it is sold as a chlorine stablizer. Read the lable to be sure you get
> the right contents. You'll need activated charcoal from a pet store.
> You'll need denatured alcohol.

> Crush charcoal with a hammer into small pieces, you only need 15 grams
> (a little over a tablespoon but this receipe should pobably be
> doubled-just use twice as much as I give here for amounts). Take 100
> grams (a little less than 1/2 cup) of Potassium bicarbonate, and
> either 84 grams (a bit over 1/3 cup) of urea or 60 grams (a little
> more than 1/4 cup) of cyanuric acid.
> Take all these dry ingredients and grind and mix as fine as possible
> (use a coffee grinder). Ratios are fairly important for scaling up or
> down, but if you have to error, do so on the side of using a little
> more urea or cyanuric acid.

> Place your powered mixture in a steel soup can or similar vessel.
> This will be the crucible that you heat for the fist form of cyanate,
> then reduce it to cyanite by the action of the powered charcoal.
> Place the can in a wood or charcoal fire, whereever you can most
> conveniently build such a thing. You can use a charcoal barbecue or
> just a big coffee can with holes punched in it and filled with
> briquettes. Heap up the coals around the can as well as can be
> managed. The powder will melt and bubble and will emit an unpleasant
> fume of ammonia (so do this away from complaining neighbors noses).
> Eventually you will have it melted to for a sort of soup or paste
> (depending on how much charcoal you added). Now the heat should be
> increased. The can's metal and it's contents should be heated until
> the metal glows orange or brighter and the contents are at least
> cherry red. (this can be accomplished by adding more hot coals and
> using a blowdryer as a bellows) Around this point the mixture should
> start bubbling again, not as fast as before, and after a while the
> bubbles will ignite when they pop, with little puffs of flame. This
> is the sign that things are working. As soon as you see this sign,
> invert an empty tuna can over the soup can of the mixture and put a
> rock on top of the tuna can to keep it in place, but not to seal it on
> the soup can (this is done to protect the hot cyanide from air as it
> is being formed, since it can re-oxidize into cyanate. The vessel
> should not be sealed because the reaction itself generates gasses that
> need to be vented) this should take a total of about 40 minutes at
> this stage (of putting the tuna can on) then 4 hours, unattended, the
> heat of the charcoal fire cool down (it may take a little longer to
> cool.
> The heating process takes the longest, but the higher you can get the
> tempertaure the faster the reaction gets done. If the can isn't
> glowing orange from the exterior, you'll need to watch it and keep the
> air stream steady to keep the heat high and constant. After the 40
> minutes, the tuna can and rock placement, and the waiting for
> everything to burn out and cool, you take the cooled can with the
> harded cyanide in the bottom out of the burned out grill or coffee
> can, and dust it off, and take it to an opened newspaper on the ground
> and with a hammer, break off the bottom of the can and now fused mass
> of cyanide and left-over charcoal. Break the fragments into pea-sized
> or smaller pieces (but don't overdo it). and then add 150 mL of water
> in a clean glass container. Let this stand in the water for 4-12
> hours, swirling or shaking the container once in awhile.
> After this time most of the cyanide should have disolved into the
> water. To separate the cyanide from the charcoal you poor it through
> two coffee filters in a plastic funnel. This removes all but the most
> fine charcoal particles. If you demand absolutely clear solution,
> first place a layer of about 1/2 inch of celite (aka diatomaceous
> earth, also available from the pool/spa supply house) in between the
> coffee filters. The pourous earth will retain more ot the cyanide
> solution but it should completely eliminate the charcoal particles.
> Now pour the aprox. 150 ml of cyanide solution into 400ml of denatured
> alcohol and vigorously swirl or stir the resulting mixture. The solid
> cyanide salt should precipitate. Filter this mix of liquid and solid
> through another coffee filter, this time gently pressing excess liquid
> from the solid that remains behind in the filter. Spread the salt out
> on a stack of paper towels to air dry and store it in a m
> appropriately labled container.
> DO NOT JUST DUMP THE WASTE FROM THIS PROCESS DOWN THE TOILET!!! You
> would be poisioning the whole septic, or waste management company in
> your area. Cyanides and cyanide-containing waste can be detoxified by
> dumping them in an excess of household chlorine bleach. Don't dump
> them down the toilet until after you do this first or you WILL KNOCK
> OUT THE LOCAL SEWAGE TREATMENT PLANT.

I tried it,but i failed my first attempt..however i obtained an hard black compound (urea,potassium bicarbonate,actived charcoal),but i failed on filtering it (lacking of equipment,bad filter paper,i see no cyanide cristal in the alcool)..although i'm not sure that this procedure is working,maybe someone with higher chemical skill than mine could examine it.

[nbk2000]

Looks like a typical k3wL'ified version of Polverone's process.

[megalomania]

I found this info, verbatum, as a repost from still another website here:
gatago dot org/alt/suicide/27269106.html

[dmitrij_medvedev]

brr...
the most simple way to get KCN from K3[Fe(CN)6] (we call it yellow blood salt) is heating up to 800 c. KCN will be at the top of flux. at last you just have to pure off the liquide cyanide wherever you want. but there will be lots of dash.
the other, but more dangerous way is destilation HCN: yellow salt + H2SO4 (30-40%) = (80C) = HCN + smth else :-) then use your alkali to turn HCN to KCN or better NaCN.
be careful!

Please use proper grammar and punctuation. - The_Duke

[tmp]

The thread starter lists the ferricyanide. This probably wouldn't work because
the equation doesn't balance out on the right. Iron hydroxide is Fe(OH)2, not
Fe(OH)3. With the ferrocyanide there is balance as follows:

K4(Fe(CN)6) + 2KOH --> 6KCN + Fe(OH)2. If this reaction would work, I'd
appreciate finding out about the conditions.

[dmitrij_medvedev]

tmp, this reaction wouldn't work. with amateur collection of chemical equipment - exactly.

In the times when America hasn't been discovered yet, european poisoners got KCN by fusing animal waste (blood with ground in the main - they include red blood salt, K4[Fe(CN)6] ) with potash.

The safest method to get cyanide - melting any of blood salts. the easiest - getting through HCN.

[Alexires]

Also, for those that don't know, instead of typing KNO3 or K4(Fe(CN)6) you can use the square brackets with the word sub (subscript) in them to designate characters as subscript (ie. [ sub ] without the spaces)

For example for K4(Fe(CN)6) you would write in your reply K4[/sub ](Fe(CN)[sub ]6[/sub ]) (without the spaces of course) and you will end up with something like this - K[sub]4(Fe(CN)6)

Just remember, if you put in a sub, you need to put an /sub to tell the computer to end the command, otherwise you will have all your writing in subscript.

[megalomania]

I hope to be adding in a pair of buttons to both the quick reply box and the advanced reply/new thread that will add subscript and superscript code in the same way the buttons work for quote, images, links, bold, italics, etc.

I had the feature before, but every update wipes the changes. I have to manually code in superscript and subscript functions, and it's worse yet to have buttons appear in the reply areas. It gets tedious to code the same changes all the time with software updates and fixes available every few weeks. Now there is a hack that enables the features without hard coding anything.

[meyer25]

Just for the record.
Ferricyanide, or more proper, hexacyanoferrate(III),
[Fe(CN)6]3- doesn't hydrolyse to
cyanide (be it HCN with dilute sulfuric acid) so easily,
because of
1. Fe3+-CN bonds being much more stable than those
of Fe2+-CN
and
2. [Fe(CN)6]3- being quite a strong oxidant
in both acidic and alkaline solutions, so alot of cyanide oxidizes.

Instead, ferrocyanides, hexacynoferrates(II) are preferentialy
used to make cyanides.

Ferricyanide can be reduced to ferrocyanide e.g. by alcalic hydrogen peroxide soln.

[simply RED]

Okay, Is the reaction possible :
K4(Fe(CN)6 + 2KOH = 6KCN + Fe(OH)2 ?

And yes, K4(Fe(CN)6 + H3PO4 is preferred, to prevent oxidation of the HCN...
HNO3, conc.H2SO4... will oxidize the HCN

[meyer25]

Okay, Is the reaction possible :
K4(Fe(CN)6 + 2KOH = 6KCN + Fe(OH)2 ?


I'd say it would, but boiling strongly alkaline (pH ~ 14) cyanide solutions results in significant hydrolysis.

[simply RED]

Okay, so, distilling crystalline K4(Fe(CN)6 + 60-80%H3PO4 remains the ideal solution for HCN synthesis?

[kurtz]

Are you aware of a comparison of yields between phosphoric and sulfuric (Gattermann method) acids?

I assume that everyone is aware of the covered crucible reaction K4Fe(CN)6 + K2CO3 -> 5 KCN + KCNO + Fe + CO2, the 1800's industrial process.

[meyer25]

Okay, so, distilling crystalline K4(Fe(CN)6 + 60-80%H3PO4 remains the ideal solution for HCN synthesis?

50% sulfuric acid, 60 - 80°C...

[dmitrij_medvedev]

50% sulfuric acid, 60 - 80°C...

The distiller should be completely tight and should not contain rubber details, course HCN simply diffuses through it. you can use sealed copper tubes for example)