Sciencemadness Discussion Board

Potassium Chlorate from TCCA

opfromthestart - 18-4-2019 at 12:11

I have heard of the synthesis of Potassium Chlorate by boiling a Sodium Hypochlorite solution and precipitating with Potassium Chloride. I am also aware of the usage of a chlorate cell, however, that is less pertinent.

TCCA (Trichloroisocyanuric Acid) is pool chlorinator and a simple source of relatively concentrated Cl in the +1 oxidation state. I was wondering if TCCA could be used along with NaOH to create either concentrated NaClO or if concentrated, NaClO3 directly.

I have added TCCA and Sodium Hydroxide together and it appeared to react very exothermically, but I am pretty much unaware of what reaction would be occurring.

Microtek - 19-4-2019 at 01:00

If you do that you may produce some sodium chlorate, but it will be mixed with large amounts of organic impurities from the cyanuric acid part of the molecule. I think a better option would be to generate chlorine gas from TCCA and HCl, and lead this into hot NaOH solution. This will produce hypochlorite, which will immediately disproportionate to chlorate and chloride.

Jules - 17-5-2019 at 05:08

I was led to believe it is more efficient to chlorinate a solution of calcium hydroxide to saturation and then heat the solution to boiling, passing more chlorine until the Ca(OH)² is again saturated with it. The potassium salt is obtained by adding KCl and crystallizing out the much less soluble KClO³, at 20°c only 8g or so in 100ml while the CaCl² stays in solution as it will dissolve around 80g per 100ml. I did this years ago in a bucket using builders lime and generating chlorine with common toilet cleaners, using LoSalt I got a mixed potassium and sodium product but it worked and was easy to purify. If I am mistaken in this I would appreciate being corrected, if someone can explain why.

Herr Haber - 19-5-2019 at 02:29

Quote: Originally posted by Microtek  
If you do that you may produce some sodium chlorate, but it will be mixed with large amounts of organic impurities from the cyanuric acid part of the molecule. I think a better option would be to generate chlorine gas from TCCA and HCl, and lead this into hot NaOH solution. This will produce hypochlorite, which will immediately disproportionate to chlorate and chloride.


Funny, I was just doing that last night except it was bubbling into 2.5 L of cold and old 14% sodium hypochlorite to fortify it while the chlorine was being used up for another reaction.
Worked wonderfully well :P

TGSpecialist1 - 20-5-2019 at 20:31

You could directly make calcium/sodium/potassium hypochlorite from TCCA and work from there.
2 C3Cl3N3O3 + 6 Ca(OH)2 = 3 Ca(ClO)2 + Ca3(C3N3O3)2 + 6 H2O
3 Ca(ClO)2 + 2 KCl = 2 KClO3 + 3 CaCl2

Calcium cyanurate is insoluble and useful for other things.
The reaction may work better if you first dissolve the TCCA then precipitate the Ca3(C3N3O3)2.
2 C3Cl3N3O3 + 12 NaOH + 3 CaCl2 = 6 NaClO + Ca3(C3N3O3)2 + 6 NaCl + 6 H2O

Fluorite - 2-1-2021 at 09:14

i added TCCA to sodium hydroxide and i saw a black solid! its like adding cotton to piranha solution! i dropped a small TCCA chunk in concentrated sodium hydroxide can this reaction release cyanogen or something??