Amos
International Hazard
Posts: 1406
Registered: 25-3-2014
Location: Yes
Member Is Offline
Mood: No
|
|
Potassium Ferrocyanide synthesis and purification?
For those of you looking for a clean step-by-step synthesis, sorry to disappoint you; this was makeshift at best. I decided to use my chemistry skills
to start making my own pigments to use in paints (I also do some art!), and found online that one can make prussian blue (Iron(III)
hexacyanoferrate(II), or Fe7(CN)18) by treating sodium or potassium ferrocyanide solutions with FeCl3. Not wanting in any way to deal with the
synthesis from hydrogen cyanide, I stumbled upon an admittedly dubious post here, and decided to entertain the idea that it might work: http://bitnest.ca/Rhodium/chemistry/cyanide.html
It describes strongly heating a fine mix of carbon(charcoal), iron oxide, and anhydrous sodium carbonate in a normal air atmosphere(largely nitrogen)
to produce modest ammounts of sodium ferrocyanide. I carried this out in crucible within my old brick furnace at just over 1000 degrees Fahrenheit for
an hour, and did indeed obtain a light yellow solution upon leaching the resulting burnt mixture. Adding a few drops of ferric chloride solution
formed a dark blue-grey precipitate in suspension, which I assumed would have been some of the prussian blue with very large contamination of iron
carbonates/hydroxides, a result of most of the sodium carbonate being unreacted and coming into solution. Is there any creative way I can either
separate the sodium carbonate and sodium ferrocyanide, or separate the two end products? I know it's a crude synthesis, so I'm not expecting much.
[Edited on 8-23-2014 by No Tears Only Dreams Now]
[Edited on 8-23-2014 by No Tears Only Dreams Now]
|
|
|
Amos
International Hazard
Posts: 1406
Registered: 25-3-2014
Location: Yes
Member Is Offline
Mood: No
|
|
All right, I'm dumping the solution. I'd like to do another run with purer chemicals and more calculation, and for a longer time, but purification is
still going to be necessary if I want some nice prussian blue.
|
|
|
Fluorite
Hazard to Others
Posts: 132
Registered: 26-12-2018
Location: United Arab Emirates
Member Is Offline
|
|
Interesting! This can be used to make cyanides from air! Also idk why nobody like synthesizing Ferrocyanides from scratch
|
|
|
ArbuzToWoda
Hazard to Self
Posts: 98
Registered: 15-7-2020
Member Is Offline
|
|
Because they are very cheap, non toxic and readily available. No need to go through all that hassle.
|
|
|
Fluorite
Hazard to Others
Posts: 132
Registered: 26-12-2018
Location: United Arab Emirates
Member Is Offline
|
|
It depends :/
|
|
|
Fluorite
Hazard to Others
Posts: 132
Registered: 26-12-2018
Location: United Arab Emirates
Member Is Offline
|
|
I burned potassium nitrate with activated carbon and (stainless steel oxide) I electrolysed stainless steel spoons to make a mixture of iron chromium
and nickel oxides 
and then dissolved this in water and I got a green solution but probably contaminated with chromates or idk
I'm desperate :3
  
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
