Sciencemadness Discussion Board

Cyanide fun question.

SsgtHAZMAT - 16-9-2007 at 22:06

Yet more fun in the sand.

As I understand it I could use Potassium Permanganate KMNO4 but I don't have any of that. So I thought of using NaClO3 and mixing it in solution. I DO have that, and a lot of it.

My question is what do you gents think that will make and when the solution evaporates as I expect it will one day will I have a different problem?

woelen - 16-9-2007 at 22:51

Actually, I think that a solution of NaClO3 hardly will react with cyanide if no acid is added as well. In neutral to basic solutions, the chlorate ion hardly reacts. If you add acid, then it certainly will oxidize the cyanide, but this sounds like a rather dangerous action. Most likely, lots of HCN will be released, especially in the hot desert conditions, and besides that, cyanogen may be released as well.

Don't you have access to bleach, or calcium hypochlorite? These make wonderful and relatively safe destruction of cyanide possible, at pH's on the basic side of the scale.

[Edited on 17-9-07 by woelen]

Sauron - 17-9-2007 at 01:49

How much of this do you have and is it NaCN, KCN or both?

I assume you want to destroy it utterly. Not just entomb it or convert it to an insoluble form?

Let's look at:

1. Incineration

-- NaCN melts at 539 and KCN at 639 C. (As an aside, a eutectic of the two is used to color case harden steel, for example the frames of Col Single Action Army revolvers.) I have not found a boiling point. I SUSPECT but have not yet substantiated that above the mp, decomposition occurs. I know that Silver cyanide for example above its mp releases Cyanogen gas (CN)2. The alkaili cyanides may release cyanogen, or HCN or both. Both are very flammable to this suggests to me that NaCN and KCN could be fed into an incinerator and the exhaust from the incinerator, burned off.

2. Acidification. Release the HCN and burn THAT, it is readily flammable.

-- Build an HCN-generator, and burn off the HCN produced.

3. Conversion to ferricyanide or ferrocyanide - make blue ink out of it. Dry that out, you have blue powder. Place in drums and bury.

4. Convert to an insoluble or low-solubility cyanide, contain and bury that

All but the last two are permanent fixes, the last two are temporary.

Anyone have any other suggestions? If not I will look into these one by one.

[Edited on 17-9-2007 by Sauron]

Sauron - 17-9-2007 at 02:58

BTW Merck says cyanides are incompatible with acids, acid syrups, permanganates, chlorates, metal salts, peroxides. But does not elaborate.

not_important - 17-9-2007 at 05:20

The Land of Oz has a little 2 page list of methods http://www.minerals.org.au/__data/assets/pdf_file/8717/cyani...

The Cyantists have their own list
http://www.cyantists.com/cyanide_treatment.html (note the link to a PDF doc on page)
http://www.cyantists.com/treatment.html

and the metal finisher's have suggestions
http://www.nmfrc.org/bluebook/sec623.htm

the DOE liked on-site chlorination-based electrolytic method http://www.nmfrc.org/bluebook/sec623.htm


The iron treatment method usually needs a polishing stage, which can be biological if the environment is right, otherwise one of the other chemical methods is used to remove the last of the cyanide. The iron cyanide complexes can be spread about to allow sunlight driven oxidation to convert them into CO2, N2, and iron oxides.

The people I know that do cyanide waste treatment like the peroxide or ozone routes, as they don't add substances that require further treatment to pass waste stream regulations.

Sauron - 17-9-2007 at 05:30

Well donw. Medium rare anyway.

It is worth noting though that all those processes are intended for dilute cyanide bearing wastewater streams white Sarge's problem I think is solid cyanide and in bulk. Furthermore he is in the desert and water is not a luxury to be squandered. So some or maybe all may not be entirely appropriate.

[Edited on 17-9-2007 by Sauron]

not_important - 17-9-2007 at 06:43

No arguing there, except that some of the plating waste streams while not solids are hardly dilute. One precious metals reclaimer would run the

Fusing an alkali cyanide with the addition of a small amount of hydroxide, then slowing adding chlorate with good stirring should convert the cyanide to cyanate; permanganate, lead oxide, and even air can also be used. If the fabrication can be done, something resembling a small Bessemer converter can be used to convert fused alkali cyanide to cyanate using a hot air blast; on a large scale anything less than that thorough exposure and mixing tends to leave unreacted cyanide. Cyanates in water decompose to the carbonate and ammonia.

I'd avoid the formation of HCN on any sizable scale, without proper equipment it's too easy to have an embarrassing accident.

Sauron - 17-9-2007 at 06:54

I agree that conversion to cyanate and degredation of that to carbonate and ammonia is preferable to HCN generation for burning off.

If Sarge has stocks of pot.chlorate at hand and has or can get lye to keep the pH high this this is probably good. Or maybe he can get H2O2 in sufficient quantity.

I think we can rule out Caro's acid. Also SO2.

SsgtHAZMAT - 19-9-2007 at 22:07

I should add it is in the form of NaCN


I have lots of bleach. Heck I made tons of it in experimenting with the Cl2 gas. So what is the formula of what it is likely to make and is it going to be a long term solution? I do however have the ability to store it for a long time once reacted. There are a lot of abandoned bunkers here that I "own."

[Edited on 20-9-2007 by SsgtHAZMAT]

Eclectic - 19-9-2007 at 22:22

Is there no practical USE for it?

woelen - 19-9-2007 at 22:55

Bleach destroys cyanide in a fairly fast reaction. Through several intermediate stages, the cyanide finally is converted to carbonate and nitrogen gas. So, if you add sodium cyanide to bleach, then the solution starts bubbling slowly with very fine bubbles. In massive quantities there might be a risk of foaming.

Roughly speaking this is what you finally get (intermediate steps are formation of lots of cyanate, which is non-toxic as well and IIRC quickly decomposes to carbonate and ammonia):

2NaCN + 5NaOCl + 2NaOH ---> N2 + 2Na2CO3 + 5NaCl + H2O

So, the bleach should be alkaline, this reaction consumes hydroxide. If the solution is not alkaline, then NaHCO3 may be formed, but also many nasty byproducts, like (CN)2 and chlorinated derivatives of ammonia.

If the reaction with bleach is carried out with excess bleach, then all cyanide is destroyed within an hour or so after mixing. Probably you will need to make a slurry of the solid NaCN, or a concentrated solution, and this should be poured slowly in the bleach, preferrably with some stirring.

What concentration does your bleach have in terms of active chlorine? Does it contain sufficient NaOH? The latter IS important, otherwise you'll make a really nasty mix. The pH of the bleach should be at least 12 or so!

Destruction of cyanide with bleach is a long-term solution, only non-toxic material like carbonate and chloride remains, most likely contaminated with cyanate. All of these are non-toxic and on long term storage you'll be left with carbonate, chloride and ammonia (from the cyanate). Excess bleach in the mix quickly decomposes, if it is allowed to evaporate to dryness in the sunshine. Bleach is not stable under such conditions and looses its oxygen. Excess NaOH picks up carbon dioxide from air and is converted to carbonate.

SsgtHAZMAT - 23-9-2007 at 19:55

Quote:
Originally posted by Eclectic
Is there no practical USE for it?



Here? Absolutely not.

Eclectic - 23-9-2007 at 22:24

No mining industry, chemical, pesticide, or fertilizer industry?

Damn. They have been bombed back to the stone age.

Sauron - 23-9-2007 at 23:02

Any pesticide industry would have been perverted by Saddam for the purpose of making chemical weapons, and would have been targeted by the USAF and RAF for maximum destruction in the buildup to Desert Storm.

SsgtHAZMAT - 25-9-2007 at 01:35

Quote:
Originally posted by Eclectic
No mining industry, chemical, pesticide, or fertilizer industry?

Damn. They have been bombed back to the stone age.



No, sort of, kind of, no. Most of these got wiped out in 1990. What was left made stuff used to kill for the most part. There was no fertilizer industry because those factories were making explosives. Plus there is not enough water for them to fertilize anything anyway.

I would say they were bombed back to the Pleistocene age, only the cities, all five of them, would be 3rd world advanced. Almost none of the women in the towns and villages read.