KClO3 from weedkiller

[Stinger]

Hi

 

I will get some weeedkiller with 75% NaClO3 in it, the rest is an inert filler: NaCl

Now I want to convert it into KClO3 to make it useful in pyrotechnics.

 

I calculated a bit and got this:

 

NaClO3+KNO3 ------>KClO3+NaNO3+NaCl

106g + 101g -----> 122g + 85g + 35g

 

Now, because of the NaCl in the weedkiller, there is some NaCl left after the reaction.

And because of that I calculated this:

 

106g of sodiumchlorate is needed to convert it into 122g of KClO3.

Then I have to take 141g of weedkiller, because only 75% are pure NaClO3

141:100*75>>> 106g of pure chlorate.

 

So, is this the correct equation?

How much water should be taken to dissolve the weedkiller and the KNO3 to get the highest rate of KClO3 precipitated out of the solution by this process?

 

Wikipedia says the aqueous solution of NaClO3 is slightly acidic, is it enough if I wash the KClO3 with ice cold water or does it need to get neutralized?

 

Thanks very much for some advices.

[oskarchem]

How would you separate the NaNO3 and the KClO3? Because NaNO3 ils very hydroscopic and all 3 salts dissolve in water

[lja]

Why not use KCl instead of saltpeter? You can get is as a water softener salt for about $12 for a forty pound bag.

 

The KClO3 will mostly precipitate out, get your solution cold and more will come out, the NaCl will mostly stay dissolved.

 

You'll need to recrystallize once or twice if your plan is to use the KClO3 for colored stars. The NaCl contamination will add yellow to everything if you don't.

[BLAST420]

wow.... I could never inmagin havin so much time on my hands that I'm fartin around with weed killer an all sorts of yip yap just to get some pot. chlo ....lol

[oskarchem]

Well, could you imadgine that some country's apart from the Us actually exist and that the law's are different. Unfortunatyly in alot of countrys you have a MUCH harder time on getting pyro chemicals, Europe and Australia are one of them... In Aus, you can have great problems finding KNO3.

[InRainbows]

Why don't you try making an actual chlorate cell? With a purity that's already reasonably high, your cell would actually be a lot faster.

 

And you would have to purify the stuff either way, NaCl ruins a lot of colored stars.

[justanotherpyro]

Cells are a lot of work to screw around with and expensive. It's not as easy as it looks. It is simpler to just do a few displacement reactions. KCl is 5x more soluable in water than KCLO3 but you will still lose a fair ammount in solution.

[Sylar]

I also thought about that. I can get 89% weedkiller for €2,5/kg!

 

Perchlorate cells are a mess though ... but with this good a deal, it's allmost like I get 75% of the messy stuff done for me.

Perchlorate cells are in need of a high quality anode aswell, and that's most of the problem for me. Pt-wire doesn't grow on trees around here.

 

Once you have perchlorate, all that needs to be done is adding K-ions to make the very insoluble KClO4 precipate out.

[flamingape]

yeah but it likes to make its home in catalytic converters...

 

junkyards FTW

[Sylar]

Good luck extracting Pt from a car catalyst ...

 

First you have to soak in warm/hot aqua regia for several weeks. Then you have to deposit it out of solution. Then you'll have to melt it into a usable form (roll a wire out of it in some way?).

And then you'll find out that there isn't all that much Pt in a car catalyst to begin with! Ofcourse, if you can get the catalyst for free, it's gonna be cheaper then buyng wire.

[oskarchem]

Or, you could just plate a wire with the Pt, jumping the step of melting it...

[Boomer]

It would be a lot easier to first remove the NaCl. It's only a few percent more soluble in hot water (read boiling) compared to cold (near 0C), while NaClO3 is a few *hundred* percent more soluble.

 

Simply dissolve as much weedkiller as possible in boiling water, filter (or simply decant), add 5% more water and cool to near freezing, then filter again. This should give you 99% chlorate in one fast and simple step.

 

After converting to K chlorate with KCl or saltpeter, recrystallize again. I honestly don't know how little Na is needed to spoil colours, but I know it's not much. The same goes for residual chlorate in the perc, if you want to use it with sulfur (or prime with BP.....). In this case, you might try to destroy it with heat, since the perchlorate is more resistant. There may even be a reducer that reduces the ClO3 ion but not the ClO4 ion.

[psyco_1322]

It should be ok with a little Na contamination if your just using it for things like whistle, flash, or bursts of some kind. Anything not color dependant.

[Mumbles]

Are you really advocating the use of chlorate based whistles, flashes and breaks. H3 is about the only sane option of the bunch. Not to say the others are possible, but not what I would be advising to people who still need to get chlorate from weed killer.

[Sylar]

Come on, you're acting like chlorate is the devil or something ...

As long as it's used with proper caution (as all fireworks should) it can be allmost just as safe as perchlorate in flash and whistle.

 

All that needs to be taken into account are the chemical incompatibilities like sulfur and other possible acidics and the slightly higher reactivity.

 

 

I happen to believe that storebought xClO3 (including weedkiller) is still alot safer that the stuff made straight from electrolysis. Industrial anodes and processes leave alot less contamination in the endproducts.

[WarezWally]

I happen to believe that storebought xClO3 (including weedkiller) is still alot safer that the stuff made straight from electrolysis. Industrial anodes and processes leave alot less contamination in the endproducts.

..... you do realize that all chlorates and perchlorates are made via electrolysis

[justanotherpyro]

They don't have to be. They can be synthesized by other means but I assume you are referring to industrial production in which case you would be correct. Electrolysis is very efficient and its cheaper for industry to produce using electrolytic cells but for the OTC DIY chemist electrolysis is more difficult but still more efficient ( and also opens the door for perchlorates rather than chlorates) than a synthesis. You gotta do what you gotta do though.

[psyco_1322]

Ive seem chlorate whistles. They are a lot faster and way more touchy than the perchlorate ones, they either fly or dont. No actually I was thinking perchlorate when I made that post. So thats a mistake on my end, sorry.

[Stinger]

Hi

 

Just for you to be sure:

 

I will NEVER mix it with sulfur or sulfates and phosphates.

It should be a fine chemistry experiment for SMALL amounts of flash powder(0,5-1g).

I could buy the chlorate, but it is much more exciting to make chemicals and being very proud of your own result and because I have weedkiller, I want to try it out.

I always prefer the selfmaking of chemicals instead of just buying, thats the point where pyro is going to be really interesting

As you might know now, I am not a kewl anymore, like the old "Polumna", so much has changed and some members here dont need to be feared that I am doing something very dangerous.

 

Thanks for the advices!

 

I will try it this weekend and post some pictures of course.

 

Greets,

 

Stinger

[Niter]

Wikipedia says the aqueous solution of NaClO3 is slightly acidic, is it enough if I wash the KClO3 with ice cold water or does it need to get neutralized?.

 

 

The best thing you can do for safety and high quality is to perform multiple recrystallizations. You are doing it for the science you say, so no trouble at all in doing some more of it, if it gets you a superior product.

 

You are talking small scale here so I won't recommend getting KCl (which is better) because KNO3 is what you have.

 

- Bring some water to a boil and saturate it with your NaClO3/NaCl mixture. While still boiling hot, pour it through a fine cloth to filter it.

 

- Bring another quantity of water to a boil and saturate it with KNO3, filter if necessary.

 

- Combine both boiling solutions and very slowly let this cool to room temperature. You want to do this slowly so there will be bigger crystals, which are easier to filter. When cooled, filter through a clean cloth.

 

- Pour a bit of water over the crystals in the cloth.

 

You now have crude potassium chlorate. Crude, so of no use to you now without purification.

 

- Boil a quantity of water and saturate it with your crude KClO3.

 

- Let this slowly cool and filter off the crystals.

 

- Now boil a quantity of distilled or demineralized water and saturate it with the purified crystals. Slowly let this cool and filter.

 

Now as to dry them.

 

- Boil a pot of water and put a dinnerplate or bowl on it as a lid.

 

- On the dinnerplate, spread out the crystals of your crop. They will dry rather well on the steam bath.

 

- When dry, put the hot crystals in a dry bowl and let it cool some place with low humidity.

 

Once thoroughly dried, pulverize and store airtight.