24 replies to this topic

[cooperman435]

if you get

if you get a household sieve with a high mesh. You can seperate them reasonably well. The larger crystals are sodium chlorate.

Sorry to say but this really doesnt work. You cant just assume that all or even most of the depresant crystals are large and that all or most of the sodium chlorate crystals are small as both chems are roughly crushed together and all the grades of powder are used together.

If using sod chl especially for fountains and rockets it is really neccecery to remove the vast majority of the depresant as it melts and forms a very hard crust causing nozzles to slowly shrink and eventually cato.

You will know if the end mix is pure by doing a 50/50 test burn with sugar just mixed in and piled on something non flamable in the open. Ash should be almost non existant and what is there should be light and fluffy. Hard peices of ash are the remaining fire depressant.

[Gary]

It is possible to synthesise KClO3 from NaCLO3 weedkiller containing fire depressant.
I am not sure whether the fire depressant is sodium tetraborate or sodium chloride, but the fact is that it does not need to be removed from the sodium chlorate if you are intending to make potassium chlorate by fractional crystallisation.
I never use sodium chlorate in my pyrotechnic compositions, because it is hygroscopic, dangerous and unstable- more so than KClO3. Also, I am not a great fan of orange-yellows in pyrotechnics. However I do use KClO3 as a burst charge (H3) for small and medium star-shells and also in some sulphurless star comps, for my blue and purple stars. I use 'lo salt' containing 70% KCl as my source of KCl. The NaCl it contains does not need to be removed.
Make highly concentrated, hot (almost saturated) solutions of the 'lo salt' and NaClO3 weedkiller, respectively, using deionised water.
Filter the solutions, whilst hot, to remove the insoluble white scum (magnesium carbonate free-flow agent).
Then add an excess of the hot, concentrated 'lo salt' (KCl) to the the hot, concentrated NaClO3 weedkiller and stir thoroughly.
Allow to cool to about 5 degrees centigrade and filter the pearl-like crystals of KClO3.
Purify the KClO3 by recrystallisation (2 times) from hot deionised water.
This should produce fairly pure crystals of KClO3.

[Caramanos2000]

How good is the yield on this?

[Gary]

How good is the yield on this?

Provided you add an [b]excess of hot, concentrated aqueous KCl ('lo salt') to the hot, concentrated aqueous NaClO3 (weedkiller), I'd say that most of the ClO3- ion is removed (precipitated) from solution as the less soluble KClO3 when the solution is cooled.
This method should give about a good 80% yield of KClO3. Of course, a small amount of a KClO3 will remain in solution (KClO3 is slightly soluble in cold water), but it is mot worth the effort trying to recover such a small amount. I think that this is an excellent method for obtaining KClO3 for small-scale experimental hobby amatuer pyrotechnics.

[hangusman]

Sorry to say but this really doesnt work. You cant just assume that all or even most of the depresant crystals are large and that all or most of the sodium chlorate crystals are small as both chems are roughly crushed together and all the grades of powder are used together.

If using sod chl especially for fountains and rockets it is really neccecery to remove the vast majority of the depresant as it melts and forms a very hard crust causing nozzles to slowly shrink and eventually cato.

You will know if the end mix is pure by doing a 50/50 test burn with sugar just mixed in and piled on something non flamable in the open. Ash should be almost non existant and what is there should be light and fluffy. Hard peices of ash are the remaining fire depressant.

If you get seperate piles of the large crytals and small crystals and mix sugar evenly with each and test the burning rate. The large crytals burn Substantually faster than the small ones. infact the small ones just crackle. Try it.

[cooperman435]

If you get seperate piles of the large crytals and small crystals and mix sugar evenly with each and test the burning rate. The large crytals burn Substantually faster than the small ones. infact the small ones just crackle. Try it.

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Im not saying it wont seperate some or even quite a bit of the depressant from the mix but not nearly enough.

As you say both piles burn at some rate or another so there has to be quite a bit of oxidider in each pile just to do that.

You would expect one pile to fail to ignite at all if it was all or nearly all fire DEPRESSANT.........

[hangusman]

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Im not saying it wont seperate some or even quite a bit of the depressant from the mix but not nearly enough.

As you say both piles burn at some rate or another so there has to be quite a bit of oxidider in each pile just to do that.

You would expect one pile to fail to ignite at all if it was all or nearly all fire DEPRESSANT.........

Yes good point. But I find it works, quite effectively infact.

[cooperman435]

Yes good point. But I find it works, quite effectively infact.

I seem to have come across wrong.


Im not trying to rubbish your techniques just explaining the problems with something you wrote to make it clear to others reading this that its not actually seperating the chems just isolating a maybe majority.

Just saying as before that if you have any fire depressant at all in the portion that you use that it will effect burn rates and leave the hard dross as a result which is not good for rocket propellants.

Also I believe that the finer you ground it into a powder that the more the depressant left will affect your composition in a negative way.

Sorry if I seemed to be being funny

[Zinginex]

Geuss it just depends on what mesh screen you got... I use this method and the sodium chlorate and sugar burn amazingly fast. I lit a pile of it under a little metal pot and it actually launched the pot into the air slightly. There was even holes in this pot so it could vent.

[hangusman]

is it made less dangerous if you used a respirator. Wondering as i never get it that fine, but if i do ill need saftey.