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Where can I get potassium ferrocyanide? Answered

Potassium Ferrocyanide is a chemical that I can use to make Prussian Blue.

I am currently looking for this so I can make some Prussian Blue or Laundry Blueing powder which I cannot find anywhere here.

Prussian Blue will be used for making crystal tree's / forrest for my daughters.

Anyone know where I can find it commonly or if I can do a synthesis of something else to extract it? 

Is it used in pottery / ceramics ( this is the best source of my random chems )



5 years ago

I have eight 500 g bottles (approximately 8 lbs total). They are reagent grade certified A.C.S from Fisher Scientific. They were part of a chemical inventory in one of our laboratories that we have since closed.

I am in the Louisville KY area where they could be picked up. I am interested in getting rid of all 8 jars. someone would have to pick them up, since I will not ship them by commerical carrier.

Incidentally, I am a chemist which is my profession.

ferrocyanide is created by heating 10 gram of potassium carbonate with 10 gram of coke and 3 gram of iron turnings. Everything should be in a coarse powder. The coke (fuel) should be produced from coals. Sodium carbonate works fine.
While occassionally stirring with an open crucible to full red heat until the emitting of flame in blue and purple are not any loner visible. Cool the solution. Filter the solution, allow to evaporate and the remaining material will begin to crystalize.
Collect the crystals and dissolve them into hot water. Cool in a temperature controlled environment, decreasing heat overtime. Large yellow crystals will form of ferrocyanide.

Sorry, I don't know much more. The potassium ferrocyanide I know was small (about 0.5 mm large) crystals with a very deep orange color, as sold in photography stores. The other way you may find it is in a medical/analytical supplies store, but of the more expensive PA kind (99.999% purity).
I have made some experiments (many years ago) with it and iron-ammonium citrate, the famous blueprint, even decorating the white cover of a book of mine with my wife photo (I made first a negative in paper).

I used to get it from photography lab stores, here in Recife, Brazil. They were used in some black&white formulas. You may also look at physician/medical supplies stores, for an expensive PA (analytical purity) variety.

Hello again! I have had some luck forming what I think is Ferrocyanide, and it would be a great help if you can confirm this. I have an image below to a photo of the evaporation.

Do the orange crystals growing up the dish look like your photography grade ferrocyanide? The photo actually lacks a lot of the orange, but in front of you it is a peachy orange.


Thank you for your help again

I'm trying to keep it cheap as its a rather simple project. I will certainly have a look around though for a photography supplies store, but I am not sure how lucky I will be with finding one nearby. Thanks, i'll tell you if I have any luck


5 years ago

Are you sure you're looking for postassium ferrocyanide? The chemical used in photographic process is potassium ferricyanide (i, not o).

I believe it's also used in the blueprinting process and making Prussian blue.

It makes a powerful bleach when mixed with fixer, and I've used it hundreds of times to reduce the density of areas in photographic prints. One simply mixes up a solution of potassium ferricyanide and water, and dabs it on a print during the fixing process.

The use of the other (postassium ferrocyanide) in photography ended when wet plates became obsolete. We were told (in college) that the ferro is somewhat more dangerous than the ferri, so I wouldn't go near the ferrocyanide...

Sorry to get technical, but if you go to a chemical supply house or buy on line, you'll end up with the wrong chemical. If you buy at a good camera store, they probably only carry the right one (the ferricyanide), so you'd probably walk out with the correct stuff. Look to camera stores in college towns, they still carry B&W processing chemicals...

I don't think you are being rude at all. I did triple check this before I wrote the question though as I noticed similarities, and yes it is ferrocyanide, but even if I had ferricyanide I can convert it to ferrocyanide. Either one is very useful. It is then mixed with Iron(III) Chloride to make the Prussian Blue.
..My daughter better like these trees lol It's worth it in my eyes, and I like to make things from scratch.

Confirmed all over at wiki: http://en.wikipedia.org/wiki/Prussian_blue

OK, I'm glad you've done your homework. I'm not a chemist, but clearly one letter makes a pretty big difference...

At the risk of repeating myself, based on what I was told the ferro is somewhat more dangerous--in the beginning era of photography there were lots of acids used for various reasons, and that's not good to have around this stuff. But in general use, and with care (and ventilation), I'm sure you'll be fine.

It is the ferricyanide that's used in photography and the blueprinting process that the others referenced. Unfortunately, I don't think you'll find the ferro at a photo store.

If you can only find the ferri, you can also make cyanotypes with your daughter...

I've just read I can make it from some basics I have here at home, sodium carbonate, carbon and iron oxide. I've also read that it is part of the process of making all sorts of cyanides, and they are only one or two steps from ferrocyanide, so there is the danger factor, i'll ask my local chemist first.

I did also read I can make some dodgy home-made Prussian Blue - leave some fine steel wool in soapy water for 2 days and collect the liquid, then evaporate. I am more thinking this is the fine steel wool with the green / blue soap stripe on them. Possibly that stripe is the bluing agent as well.

Thanks for the next thing to do with the chemical, I will definitely give that a go as well!

By the way, none of this would have been found without the help of your answers!


5 years ago

It used to be a blue line chemical for photo sensitive paper for replicating engineering drawings with strong light now there is an ammonia  process.
Try ebay or copier chemical supply.