| Pages:
1
2 |
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
KOCN
I have made several attempts to make KOCN from urea and KOH based on the guidance of US patent 3935300 (Feb 20, 1974), and encouragement from Hilski.
My urea is PTS brand fertilizer. KOH is technical.
I mixed finely ground urea and KOH at a 2:1 mole ratio of urea:KOH. This was placed in an assay crucible and heated gently but steadily (at ~130C)
until foaming stopped. This product was then placed in a muffle furnace preheated to 240C. Heating at this temperature was continued for 6 hours.
What resulted was a soft, light brown clinker. This was ground up, mixed with water, and filtered. Suspended mud was discarded. The filtrate was
mixed with 95% ethanol and the resulting ppt caught on a Buchner funnel. This was dried and weighed. Assuming it was KOCN the yield was 12%.
Placing some in water the pH was 9. Melting point is >280C (limit of my silicone mp oil).
I'm very skeptical that I actually made any KOCN (mp 315C). However, I don't know of any way of proving, or disproving, this.
Nicodem, in a recent post on the MSG thread says:
| Quote: |
(NaOCN or KOCN can easily be prepared in a home lab).
|
If he, or anyone else, can tell me what I'm doing wrong, or provide a better procedure I will be grateful.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
Hilski
Hazard to Others
Posts: 197
Registered: 13-9-2006
Member Is Offline
Mood: No Mood
|
|
I, like Magpie have no real way of determining what I actually made using the procedure in the patent he referenced. But I did try a few things which
varied from the patent, so I will describe the basic procedure I used.
For one, I didn't bring the temperature to 130C and leave it there for any real length of time. I added the KOH and urea to the vessel I was using,
and turned up the heat as high as it would go. The urea melted at 130 like it was supposed to and everything kept bubbling reacting and emitting
ammonia fumes for some time. Right around 180C, everything went solid, pretty much like the patent said it would.
Also, I didn't use an oven the keep the temperature at 240C after the initial reaction. I basically just left the mixture on the electric hotplate
turned up on high for about 5 hours. I used a Fluke infrared thermometer to measure the temperature on the surface of the mixture from time to time,
and it remained a solid at or about 240C the whole time.
I dissolved everything in water, and filtered out the brown stuff as Magpie mentioned. Then, I boiled off a lot of the water and poured what was left
into a beaker of cold denatured alcohol to precipitate the alleged KOCN, which was then vacuum filtered.
I used 21g urea and 10.3g KOH for the reaction. This is close to a 1.9:1 molar ratio, which the patent claims is ideal for best yields. I don't
remember what the actual yields were, but I do remember that they were a good bit lower than I expected.
Like I said, I really don't know a way to test the result to see what % KOCN was actually made, so they yields may have even been lower than I think
they were.
\"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety. \"
- Benjamin Franklin
|
|
|
leu
Hazard to Others
Posts: 368
Registered: 13-10-2005
Member Is Offline
Mood: No Mood
|
|
The usual industrial method is to use an alkali metal carbonate as the base instead of the hydroxide:
Manufacture of alkali-metal cyanates. (du Pont de Nemours, E. I., and Co.). Brit. (1969), 5 pp. CODEN: BRXXAA
GB 1145777 19690319 Patent written in English. Application: GB Priority: US 19660801 - 19670710. CAN 70:116709 AN 1969:116709 CAPLUS
Abstract
Na cyanate (I) or K cyanate (II) of 98% or higher purity, free of cyanide is obtained by the low temp. reaction of stoichiometric amts. of tech. grade
alkali metal carbonate and shotted urea in the presence of a suitable quantity of a heel of 98% purity (45 and 55 wt. % of the heel for manuf. of I
and II is of the reaction mixt., resp.) in muller-type mixers or screw conveyors having provision for intensive mixing and rubbing and a suitably
efficient heat transfer arrangement. A small excess of urea (.apprx.2%) is desirable to eliminate contamination from unreacted alkali metal
carbonate. The low operating temps. employed in the process (95-150° and 95-225° being the optimum ranges for I and II, resp.) do not cause severe
corrosive conditions and permit the use of cast iron, wrought iron, or stainless steel reaction vessels and batch or continuous operations are
practicable. Heating times of 4-7 hrs., depending on mixing and heat transfer characteristics are required for completion of the reaction. Cyanide
impurity detected in the end product is <1 ppm. Thus, charge a jacketed, stainless steel, double-arm mixer, heated with steam at 110 psig. (173°)
with 5.20 parts of heel of I of 98% purity. Engage the blades turning at 50 rpm. and heat for 1.8 hrs. to 164°. Add 2.25 parts soda ash and 8 min.
later 2.25 parts of shotted urea. Heat the slightly wet and lumpy charge for 6 hrs. After 2 hrs., the batch becomes free-flowing and dusty. Vent
off the discharge gases throughout the heating period. The yield obtained of 7.8 parts I from the mixer is 99.5% based on the starting amt. of urea,
with a purity of 98% and shows <1 ppm. cyanide. About 86% I is formed during the 1st hr. while the temp. of the mix reaches 140° and 94.9% of the
total product synthesized is formed in 2 hrs.
and
US4000249
Sochol, et al. December 28, 1976
Preparation of alkali metal cyanates
Abstract
Process for the preparation of alkali metal cyanate by the reaction of urea and alkali metal carbonate. The addition of water to the reaction in an
intermediate step activates partially blocked alkali metal carbonate and provides an alkali metal cyanate product of high purity.
Chemistry is our Covalent Bond
|
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
Calcium cyanurate decomposes to HOCN gas and solid calcium cyanamide under mild orange heat. The HOCN could be bubbled through NaOH or KOH leaving
the cyanate.
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
YEe Ha indeed  .
Just to save the search:
http://www.sciencemadness.org/talk/viewthread.php?tid=8594&a...
Cheers,
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
Hilski
Hazard to Others
Posts: 197
Registered: 13-9-2006
Member Is Offline
Mood: No Mood
|
|
| Quote: | Abstract
Process for the preparation of alkali metal cyanate by the reaction of urea and alkali metal carbonate. The addition of water to the reaction in an
intermediate step activates partially blocked alkali metal carbonate and provides an alkali metal cyanate product of high purity.
|
I tried that procedure also. I didn't see any difference in yield, but the product possibly could have been more pure. I have no way of knowing.
\"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety. \"
- Benjamin Franklin
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
The_Davster says:
| Quote: |
Calcium cyanurate decomposes to HOCN gas and solid calcium cyanamide under mild orange heat. The HOCN could be bubbled through NaOH or KOH leaving the
cyanate.
|
That's an interesting approach. I wonder what the relative poisonous level is of HOCN vs HCN? 
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
Polverone
Now celebrating 21 years of madness
Posts: 3186
Registered: 19-5-2002
Location: The Sunny Pacific Northwest
Member Is Offline
Mood: Waiting for spring
|
|
I would use the procedure found in Inorganic Syntheses vol. 2. They've already done the heavy lifting of adapting and validating the patent literature
for lab scale preparations.
PGP Key and corresponding e-mail address
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Thank you, Polverone. I'll check out that reference.
I just dissolved some of my preliminary KOCN in water and then added some AgNO3. I did get a white precipitate. So it likely is at least partially
composed of KOCN. Could be some cyanide in there too I suppose. But I don't think it was ever hot enough to form that.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
Cesium Fluoride
Harmless
Posts: 48
Registered: 26-1-2005
Member Is Offline
Mood: Cupric
|
|
What about decomposition of potassium cyanurate directly into potassium cyanate? I have a couple of sources that say that cyanurates decompose into
cyanates. I suppose a potential problem would be that the cyanatewould further decompose into cyanide.
Is this at all a practical method?
|
|
|
The_Davster
A pnictogen
Posts: 2861
Registered: 18-11-2003
Member Is Offline
Mood: .
|
|
From the depths: https://sciencemadness.org/talk/viewthread.php?fid=2&tid...
Cyanuric acid can be fused with alkali carbonate.
|
|
|
Cesium Fluoride
Harmless
Posts: 48
Registered: 26-1-2005
Member Is Offline
Mood: Cupric
|
|
Thanks I was actually looking for that patent but I lost it in my files. It states that significant decomposition of cyanate to cyanide takes place at
temperatures lower than 500C when operated in air so that's why a CO2 atmosphere is employed.
From what I can tell, it doesn't matter whether the free acid is fused with carbonate or if a salt of cyanuric acid is heated- both will result in
cyanate, and in an oxygen environment, a good deal of cyanide.
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
Heating plain cyanuric acid to around 300 - 380 C gives cyanic acid and other products. You could condense it at 5 C or so to separate it from some
of the less condensible products, and continuously & immediately react it with a base to get the cyanate salt.
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Cesium Fluoride
Thanks I was actually looking for that patent but I lost it in my files. It states that significant decomposition of cyanate to cyanide takes place at
temperatures lower than 500C when operated in air so that's why a CO2 atmosphere is employed.
From what I can tell, it doesn't matter whether the free acid is fused with carbonate or if a salt of cyanuric acid is heated- both will result in
cyanate, and in an oxygen environment, a good deal of cyanide. |
That does not make any sense. How can HOCN be reduced to HCN (or cyanates to cyanides) in the absence of a reducent? And why would an oxidative
atmosphere help the reduction and absence of O2 prevent it?
In my experience the trisodium or tripotassium salt of cyanuric acid easily decomposes to NaOCN or KOCN if heated already on a hotplate (I would say
that is about 300°C or less). Of course, no cyanide formed even though the heating was done on air.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
|
|
|
Cesium Fluoride
Harmless
Posts: 48
Registered: 26-1-2005
Member Is Offline
Mood: Cupric
|
|
| Quote: | | That does not make any sense. How can HOCN be reduced to HCN (or cyanates to cyanides) in the absence of a reducent? And why would an oxidative
atmosphere help the reduction and absence of O2 prevent it? |
I understand what you mean, but I was simply summarizing patent GB710143. Here is direction citation:
| Quote: | | Alkali metal cyanates have been found, however, to decompose in air at 500-900C to give a variety of products including cyanide. We have indeed found
that such decomposition occurs even below 500C in air. Even in an atmosphere nitrogen free from oxygen, decomposition of cyanate to cyanide has been
found to occur, although no sources of ammonia or hydrogen were present. Even at 500C, 7% decomposition occurs on heating sodium cyanate in nitrogen
for one hour, and sodium cyanide is prominent amongst the decomposition products. Such formation of cyanide is obviated at temperatures up to
550C by operating in an atmosphere of carbon dioxide, whether in reactions with calcium cyanamide as described in USP 2,208,033, or in
reactions in absence of calcium salts according to the process of the present invention. |
You tell me...completely bogus?
| Quote: | | In my experience the trisodium or tripotassium salt of cyanuric acid easily decomposes to NaOCN or KOCN if heated already on a hotplate (I would say
that is about 300°C or less). Of course, no cyanide formed even though the heating was done on air. |
Great! That's probably exactly what I'll end up doing. A bit of cyanide doesn't even really bother me, but according to the above info, you produced
at least some CN-.
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
I was able to find a copy of the potassium cyanate procedure in Inorganic Syntheses, vol II.
It calls for the mixing of 70 g of K2CO3 with 80 g of urea in a porcelain evaporting dish and heating until a melt results.
My first attempt was with a 1/3 scale batch in a 6" porcelain evaporating dish. Because of too rapid and/or uneven heating the dish cracked.  I didn't use a wire gauze either.
Today I heated a 1/10 scale batch in an aluminum drinking cup placed on a wire gauze. At first there is some melting (urea I suppose) and
off-gassing. Then some more off-gassing. Eventually this stops. Then gradually turning up the heat it begins to char and at full heat it melts with
some foaming. I then placed the mostly solidified melt into a mortar and ground it to a powder.
The procedure claims a clear melt and says nothing about charing. I didn't see this. It claims a 94% yield. Mine was 77%, but I did have a much
smaller batch.
The powder dissolves very quickly in water and gives a strong test for cyanate. (The cyanate test is given in the procedure and merely consists in
adding a few drops of a solution of a cobalt salt to a small sample. A blue color is positive for cyanate.) It also tested positive for carbonate.
(This test calls for Ba(NO3)2 and is also in the procedure. The procedure also provides tests for ammonium ion, urea, and cyanide.)
The picture below shows the KOCN in the weighing pan. The two test tubes with blue solution are the results of the cyanate test.
This procedure was written by Allen Scattergood and checked by Don R. McAdams and James P. McReynolds and I would think it should be pretty solid.
What puzzles me most is that they make no mention of charing and refer to a clear melt that I never saw. One possibility is my materials. They call
out USP grade K2CO3. Mine is pottery grade. My urea is fertilizer grade. They likely used a lab grade.
If others have tried this procedure I would be very interested in hearing of their results. I would also be interested in any ideas as to why I'm
getting this charing.
Edit: Later testing (titrating wth dilute HCl) showed the product is at least 50% K2CO3.
[Edited on by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
Aqua_Fortis_100%
Hazard to Others
Posts: 302
Registered: 24-12-2006
Location: Brazil
Member Is Offline
Mood: †
|
|
just a doubt..
If the trisodium or tripotassium salt of cyanuric can form cyanates, will worth a try mixing powdered stoichiometric amounts of trichloroisocyanuric
acid and KCl , moist and heat very mild to give chlorine and then washing with alcohol ,dring a bit and heat with care (or not) depending if you want
make KOCN or KCN (?) I think that this can be made, although Polverone related in other thread which cyanates undergo hydrolisis,decomposing, and
also some of the reactants would probably contaminate the formed salts..
But maybe the main advantage can be the fact that making KCN is easily than NaCN (also explained by Polverone) by pyrolising KOCN and also KOH
(watched chemical in many places) isnt needed,since we would be using OTC KCl.. and as side benefit you can get chlorine...
I'm remembering also which this is a subject in a thread on E&W, but cann't remember..
so, what about?
"The secret of freedom lies in educating people, whereas the secret of tyranny is in keeping them ignorant."
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Aqua_Fortis, I don't see what the driving force for your proposed reaction would be.
Making KOCN in decent purity has become an obsession for me. I don't have any great purpose for it. It's just pissing me off that I can't prepare
it.
I have tried numerous patents that claim it can be made with urea + K2CO3, or KOH. None have been satisfactory in my opinion. The prep from
Inorganic Synthesis did produce some poor quality KOCN, however.
Right now I have two slow preps going simultaneously in my lab. The first is KOH refluxing with urea in denatured ethyl alcohol. I found a reference
to this in a book on nitrogen chemistry. It refered to a paper in Ber,1887, a very old German paper I imagine. (I don't have the paper per
se.) Some wispy white ppt is forming but only very slowly. NH3 is drifting out of the top of the reflux condenser equally slowly.
The second is an isocyanuric acid + KOH solution being evaporated down to, hopefully, potassium cyanurate. Then I'll heat that to form KOCN.
If these two methods also fail I will be left with decomposing isocyanuric acid to HOCN and piping this into a KOH solution. This is understandably
the last on my list.
I have no intention of trying to make it by oxidizing KCN. Not that that wouldn't work, it just seems like cheating,
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
Aqua_Fortis_100%
Hazard to Others
Posts: 302
Registered: 24-12-2006
Location: Brazil
Member Is Offline
Mood: †
|
|
Oh Magpie , sorry.. I really should have missed something..
| Quote: | Originally posted by Magpie:
I don't see what the driving force for your proposed reaction would be |
well if I understod correctly, if you react HCl with TCCA and some heat to complete the reaction, you will get Cl2 and cyanuric acid, right? So the
same can probably apply to alcaline chlorides,etc..being 3 mols of xCl for each of TCCA..
| Quote: | If these two methods also fail I will be left with decomposing isocyanuric acid to HOCN and piping this into a KOH solution. This is understandably
the last on my list.
|
well, if you are obcessed with purity, this don't seem to be much reliable .. Since cyanuric acid decompose not only to HOCN, but a lot of more
products, as said before..
| Quote: | The second is an isocyanuric acid + KOH solution being evaporated down to, hopefully, potassium cyanurate. Then I'll heat that to form KOCN.
|
What the difference ,in your viewpoint , advantages and disadvantages between fusing cyanuric acid and a hidroxide without water and reacting both in
an aqueous solution ? I'm little confused about that (side reactions,etc) , but still betting in aqueous solution + alcohol method..
I'm obsseced also in these chemicals..but more in KCN(for recovering gold from E-stuff and also from local ore) than KOCN, and the last seem to be
great as start for me.
BTW , also planning in making my own TCCA , just for fun
[Edited on 12-10-2007 by Aqua_Fortis_100%]
"The secret of freedom lies in educating people, whereas the secret of tyranny is in keeping them ignorant."
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Aqua says
| Quote: |
well if I understod correctly, if you react HCl with TCCA and some heat to complete the reaction, you will get Cl2 and cyanuric acid, right? So the
same can probably apply to alcaline chlorides,etc..being 3 mols of xCl for each of TCCA..
|
I suspect that part of the driving force for the HCl reaction is the formation of the weak acid: cyanuric acid. But by all means try the KCl. 
By Aqua:
| Quote: |
well, if you are obcessed with purity, this don't seem to be much reliable .. Since cyanuric acid decompose not only to HOCN, but a lot of more
products, as said before..
|
I thought it just decomposed to HOCN.
Aqua:
| Quote: |
What the difference ,in your viewpoint , advantages and disadvantages between fusing cyanuric acid and a hidroxide without water and reacting both in
an aqueous solution ? I'm little confused about that (side reactions,etc) , but still betting in aqueous solution + alcohol method..
|
Making the potassium cyanurate in aqueous solution avoids dealing with HOCN. This is then heated to form KOCN. It may or may not work - time will
tell.
My attempts at fusing KOH and K2CO3 with urea or isocyanuric acid have not been satisfactory, despite all the patents.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
Polverone
Now celebrating 21 years of madness
Posts: 3186
Registered: 19-5-2002
Location: The Sunny Pacific Northwest
Member Is Offline
Mood: Waiting for spring
|
|
Magpie, I've seen the charring you refer to before, though I was always on the way to cyanides and didn't mind the addition of a little more carbon. I
don't know if it's something expected but generally not mentioned, or if it's a consequence of using fertilizer grade urea. Personally, I would try
the Inorganic Syntheses procedure again, this time using pure urea and K2CO3, before attempting obscure century-old procedures.
If you have any high-grade potassium hydroxide or bicarbonate on hand, I'd try using those to prepare the K2CO3 that you will use. If not, it might be
worth ordering a bit of reagent K2CO3, KHCO3, or KOH to satisfy your burning curiosity. The same may be said of the urea, or you might want to just
try purifying the fertilizer before using it.
According to at least some references, even dilute acids will cause cyanates to liberate cyanic acid with decomposition to ammonia and CO2. I'm not
sure that hydrochloric acid titration is a reliable carbonate indicator.
You could also order a minimal quantity of reagent potassium cyanate so that you have a reliable standard to work against.
PGP Key and corresponding e-mail address
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
After refluxing for 11 hours there was no significant production of insoluble KOCN in the alcoholic KOH/urea. It gave only a slight positive (blue)
when tested with Co++.
I haven't tried heating my tripotassium cyanurate yet, if that is indeed what it is.
Polverone it seems like you have a good point about the reaction of HCl and KOCN. Using the brown powder previously made with the Inorganic
Syntheses procedure, I get a strong blue test before the addition of HCl, and no blue once all fizzing stops after adding HCl. It would be
better to test for CO3-- using Ba++ as the Inorganic Syntheses procedures recommends.
I will try the Inorganic Syntheses procedure again. I should be able to purify my urea and K2CO3 via recrystallization.
I may just have to accept some charring and/or remove this in a workup of some kind. I think this could be minimized if a hot bath was used to get the
KOCN to a melt (320C) instead of my propane bunsen burner. I just don't happen to have any Wood's metal or such on hand.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
I've had some encouraging results today in my quest for KOCN:
Yesterday I had dissolved 4g of swimming pool grade isocyanuric acid in 400 mL of water. Then a stoichiometric amount of KOH was added to form the
tribasic salt. (I later found out that isocyanuric acid is soluble in aqueous KOH, so it would have been wiser to do this in reverse order and cut
way back on the water.) My salt solution was then reduced to dryness by evaporation on a hotplate, resulting in a slightly crumbly white powder.
Today I heated this powder to a liquid in a small aluminum cup using a bunsen burner w/gauze. Once the bubbling stopped I poured the melt into a
mortar and ground it to a powder. There was very little charring and the final powder was white.
Now I carefully tested it with Co++ (for OCN-) and Ba++ (for CO3--) against the brownish KOCN I had made earlier using urea and K2CO3. For the Co++
test the blue was just slightly more intense for that made with the acid. For the Ba++ test first results were much more favorable for the KOCN made
from acid, with no ppt. Further testing showed BaCO3 ppt was formed, but it still seemed to be an improvement.
I am now contemplating firing both of these products in my muffle furnace in an attempt to convert them to KCN. This could then be titrated with a
standard AgNO3 solution to determine the %KOCN.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
ciscosdad
Hazard to Self
Posts: 76
Registered: 6-2-2007
Member Is Offline
Mood: Curious
|
|
Nice work Magpie.
Keep at it.
I've seen Cyanuric acid on the shelf while cruising the pool chemicals section in the local hardware store (as we all probably do!). It seems such an
interesting chemical.
I've had a brief look around, but there does not seem to be much said about Cyanuric acid in the literature (reactions). Has anyone seen anything
comprehensive? Everything I've seen is frustratingly brief.
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Thanks ciscodad. It seems my efforts are finally starting to pay some dividends.
This whole investigation of urea/cyanuric acid/KOCN/HOCN/biuret chemistry has been both interesting and perplexing. There is some information out
there but as you say it can be hard to find. It seems most of the work was done back in Wohler and Lebig's time and has been forgotten since. What
was most frustrating for me was trying a bunch of patents that didn't pan out.
Cyanate is pretty much insoluble in everything except water. Then in water it's subject to hydrolysis. KOCN also has a tendency to convert to K2CO3.
So it's hard to work with.
Some results from recent tests on my product made from isocyanuric acid:
1. Placed ~30mg on a watchglass then added 3-4 drops of 10%HCl. Got a biting whiff of "acetic acid smell." This should be HOCN and is a good sign.
2. Realized that Co(OH)2 and CoCO3 are insoluble. So treated some KOCN solution with the BaNO3 first to take down the carbonate. Centrifuged.
Added the Co(NO3)2 solution to the supernate for a strong blue color that persisted. Final pH was 8. It's too bad I don't have a spectrophotometer
and some standard KOCN. With these I could likely determine the purity of my product.
3. Treated the centrifuged residue with 10%HCl. Surprisingly not much bubbling here. So not a carbonate. What it is I don't know.
4. Treated the supernate with some 10%HCl. Little stream of bubbles. When gently heated a great deal of bubbles. Assumed that the bubbles were
HOCN.
I have hope that I can make some more product of even better quality. I'm trying to avoid use of K2CO3 as this is what I don't want in my product.
My plan for tommorrow is to make a larger batch from the isocyanuric acid and do some more testing.
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
