What Went Wrong in My Attempt to Make Potassium Chlorate?

[dauphin115]

Very well!
I know that is very difficult to control current efficency I read more and more on www about this, they are some experimental setup for chlorate cell, I read about electrode position into cell, anode on the bottom and catode on the top (anode under catode) the Cl2 gas that are formed at the anode to go up and "meet" the OH- that are formed at the catode, this setup help the formation of chlorate (not more but..), stirring the solution is another way to increase the current efficency because help the dissolution of Cl2 gas.
pH controller:
about this, the probe measure the concentration of H+ ions, the output of probe is a measure in mV that the pHmeter convert in pH value, I don't know more about this but I know that the presence in solution of ionic/cationic species don't influence the mV value ( it depend only on H+ concentration) so is possible to measure the value of mV (with sensible mV meter) and build an apparat that add in the cell HCl if the value of mV change.
The current efficency is more influenced by the value of the pH and you can obtain a good current efficency value only if you control pH.
I have a question for you; You use chlorate for your experiments or use it for preparation of perchlorate?
Hi Emiliano

 

[mrjeffy321]

For right now atleast, I use the chlorate I make for experiments (pyrotechnic, rockets, ...).

 

[Sparkee]

PH Meters...

Glad to hear that it produced for you! Please let me know how your devices turn out. In my case I was able to achieve some spectacular results. One problem was getting the Al processed to a fine enough mesh. If it is not you end up with a fountain instead of a "BANG". BE CAREFUL!
Check out this link for PH/MV/T meters, WWW. Grainger.com

 

[mrjeffy321]

In the mean time, while we wait for my current chlorate cell to compleate, here a question about contruction of the cell.

I know you, Sparkee, made a pretty eleborate cell with lots of electrodes and a cover and it looked very well made.
My cell isn't quite so big, I am reluctant to make an eleborate cell just yet before I can pretty much perfect my process I will use and before I gather the materials needed (and get a better power source).
Right now, what I have is a plastic penut butter jar, about 5 inches tall and 3 inches wide. As my electrodes I use 3 (2 cathodes, 1 on either side of the annode), made of recangular chuncks of graphite. This basic system seems to work well, but my main problem, which I didnt get into before on my last trial (probably because it was outside), is that the copper wire I use to connect the power supply to the electrode gets corroded very easily and breaks off, this breaking the circuit. I have a lot to prevent this, I have wrapped it in tape, then I covered it in hot glue, then I covered it in some rubber cement type glue, then I covered it with both glues, then I got some water putty that dried hard around it and used that, and in all cased, with in 24 hours (many times less) of continuous running, the wire corrodes and needs to be replaced. the problem is occurring because of the chlorine gas being made at the annode that is rising up and corroding the copper, it seems to get through any barrier I give it, eventually.

Any suggestions on how I can prevent this from happening, or at least delay it much longer?

 

[pack_rat2]

...What about this as a way of purifying the product, set the crushed powder in a finter and slowly pour a small amount of cold water over it...

I've been away for a little while due to the holiday season, but now I'M B-A-A-ACK...! ;) As for purification, the accepted method is recrystalization. Heat up water to the boiling point and dissolve as much KClO3 as it can take, and a little more. Pour off the clear solution and cool it down. Pure crystals of KClO3 will precipitate out. Just keep doing that until all the KClO3 has been processed.

 

[mrjeffy321]

Hey, it has been a long time.
But wouldn't this method inevitibly leed to the loss of lots(7g/100mL) of perfectly good KClO3?
For example, if I decided to purify 100 grams, I would need to use about 1.4 Liters of water to dissolve all of it and I would get very little back.
Or is the idea insted not to redissolve it, but rather just get it wet and thus dissolve the impurities?


Any suggestions on the electrode problem?

 

[Sparkee]

Having the cover on my set up helped ,also I used magnet wire (26 ga.) you might try shrink tube also. On the end of the electrode where the wire attaches I used hot glue and shrink tube for some protection and tried routing the wires up and away from any obvious problems. At about the halfway point of the process I did replace all the electrodes as they were eroded to the size of pencil lead. I didnt have any of the wires corrode. I think that having the tight fitting cover helped by allowing me to route the chlorine gas away from any problem areas. Make no mistake corrosion will be an issue! I had mine set up in my shop even with an exhaust fan I still had problems. Anything that was not stainless steel was affected. Several of my hand tools in the vicinity have a nice layer of rust. I still find chloride/chlorate accumulated in places when the humidity is high. From that I learned that when next I run a cell it will be outside.

 

[mrjeffy321]

I find I get best results using a combination of hot glue on the bottom and this runnery type glue called, "goop" on top. Right now I added a middle layer of wax to see if that will do any good, but the jury is still out on that.
I think I will try to set up some type of lid to divert the gasses away, but this will be hard considering how low to the water leve the wire is. it might be a better idea if I just redesign the whole cell, but I wanted to wait before I did that until I got at least one reliable, high amperage, power supply I can count on now breaking, otherwise I'll have to wait years to get a bucket of NaCl(aq) turned into NaClO3.

 

[Chronos]

You can buy the stuff at the grocery store. It's called lite salt.

 

[mrjeffy321]

The 'lite Salt' you are referring to is actually a mix of Sodium Chloride and Potassium Chloride, thus containing less (lite-er on the salt) "salt" than normal salt. But I would need pure Potassium Chloride, no sodium chloride (that is just a by product of this reaction), so I use something called, 'NoSalt', also at the grocery store, but a tad more expensive.

by the way, the wax idea worked terribly.

 

[pack_rat2]

Hey, it has been a long time.
But wouldn't this method inevitibly leed to the loss of lots(7g/100mL) of perfectly good KClO3?...Or is the idea insted not to redissolve it, but rather just get it wet and thus dissolve the impurities? Any suggestions on the electrode problem?

You just say the solution you have at the end of the purification, until your're ready for the next batch. Sure, you'll always have some left over, but if you keep making it, that amount doesn't increase. And you MUST dissolve it in order to purify it, since the impurities are locked into the crystal structure. As for electrodes...platinum is what's recommended! I bet you just loved to hear that. I've read something about stainless steel and carbon rods, for those of us who aren't rich.

 

[pack_rat2]

I posted a link on the thermal method; it also has info on electrolysis. Here it is, again:
http://www.wfvisser.dds.nl/EN/chlorate_EN.html#thermal

 

[mrjeffy321]

platinum is what's recommended!

I, no problem, I will just reach into my vault and pull out a couple bars.
I am unsure on how well platinum would work, or for that matter silver or gold (what about nicrome wire?) would work almost as good, but would a platinum electrode work perfectly with no corrosion or erroding? or would it eventually. I was under the impression that no matter what I used, it would get corroded but at diferent speeds.

Saving the water used for purification, good idea. But then it gets complicated if you want to do a batch a diferent size than the amount of water you have, .. time to get out the measuring cup and esimate what is dissolved already.

Does anyone know what the average purity of KClO3 is without purification, through either method (if there is a diference)?
Then once it is purifies, doesn't it get to be pretty close to 100%


Sparkee [or whoever wants to answer], a while back (many posts), you said that you used an "hour meter" to help you measure the total amhours into your cell. I was looking around, considering getting one, but I don't really know what to look for, I found a wide range of styles, prices and desciptions. I foun something called an hour meter, but it is used to meaure the time elaped on electrical motors and what not and I am unsure if it is the same thing you had. also, there seems to be specifcations on the voltage that the hour meter uses, does this matter if my cell is not within the hour meters range?
example of what I found:
http://amos.shop.com/amos/cc/main/ccn_search/st/%22hour%20meter%22/sy/productsx/ccsyn/260/prd/8197242/ccsid/324920718-20893/adtg/02100541

 

[Sparkee]

It was (is) just a standard analog hour meter using line voltage. Run in series with your power supply line side. The one I use came off an old compressor control panel that I demo'ed a while back. I set it up so that when I switched on the power supply it would engauge a relay and begin recording. Through this I also ran the heater ( aquarium type) so that when I performed the daily maintainance(Ph,etc..) that the heater would also shut down. If you happen to forget to un plug the heater when you pull it out bad thing's can happen. The glass tube encasing it will shatter exposing the element and you have 120v exposed. Not good! I admit that my setup was probably over done. Had a lot of time on my hands. But, What the heck keeps me out of trouble.Let me know if I can be of help. The one your link showed is DC I suppose it would work. Mine ran off 120v so I was able to keep it farther away from the cell (corrosion,etc...)

 

[pack_rat2]

"...[Y]ou said that you used an 'hour meter' to help you measure the total amhours into your cell..."

If you can't find one or can't afford one, you can do it the old-fashioned way. Put an ammeter in series with the circuit, and make a note of the current. Then, at periodic intervals, check the current and record it. For each interval, calculate the average (sum of the current at the beginning and end of the period, divided by 2), then multiply that value by the length of the time interval. Then add up the values of all the intervals for the total. This method isn't as accurate as using a meter that measures current*time continuously, but it should be more than adequate.

 

[mrjeffy321]

that is essentially the way I do it now, but it is so time consuming, keeping all those records of what the current was at each interval.
also, when I can't tend to it all the time (like when I goto sleep), a lot of times it stops because of some problem, and i never know when to estimate the stopping time was. if I can find one cheap enough, it think it would worth it to me convience wise to get one.

I am roughly into my 440th amp hour on my second trial of my chlorate cell, only about 210 more to go.

 

[mrjeffy321]

OK, it is finsished after long last, my second trial is done, the Chlorate has been extracted, dried, and weighed.

Stats:
-Started with 180 grams of NaCl
-dissolved in 500 mL of water
-should have taken 650 ah to convert 90% of it at
-estimated 55% efficency (what I estimated it would be from the begining)
-I ran it for the full 650 ah, by my log (which inclues soem rounding, but more on that later).

Theoretical maximum amound of KClO3 that could have been made by convering 90% of the 180 grams of NaCl: 272 g.

Actual yeild: 140 grams
% success: 51.5$
Actual efficency: 28.3 %


This is pathetic, I am ashamed of these results, it is stuff like this that makes me think I forgot a decimal somewhere because this is horrible!
I let this cell run for the entire month of Feburary to get the 650 ah needed, then I spend a week extracting it and letting it dry, crush it up and weight it, and all I get is a measly 140 grams, (just a small jump from my last cell), and I should have theoritcally gotten 272 grams.
sure is a lot compared to how much I used to be making, but I spent so much time on this, changing electrodes, keeping careful logs, adding HCl, ... and something must have gone terribly wrong for me to get only 28.3% efficency, I could have done nothing and got better than that. I did do some rounding and estimating, but I don't think this could have made that huge an impact on my results.

This really makes me want to redesign my cell, but there are so many complications, I don't know where to start.
if/wheh I redesign it, its main purpose would be to produce chlorate, but I also want to be able to collect/divert all the gasses (speratly) that come off the electrodes.

 

[redwraith94]

mrjeffy321: Boiling bleach decomposes it from 3 x NaClO to 1 x NaClO3, 2 x NaCl

Platinum electrodes can be used, but they have to be uber pure, even .01% rhodium/some other similar group metal will give the electrode a set service life...this is considering electrodes that are usually copper core, niobium alloy 1st plating, then platinum over-plating (usu ~100-250 microns thick or so)

Graphite works fine, and they are much cheaper, I just got a quote for platinum clade copper rods. 2 x rods 1 foot long each with a 100 micron plate 1/4 inch full diameter...90 dollars US...too much money for an electrodes w/ ~5,000 hrs service life? lol.

Finally, don't be ashamed of your results. A big thing that comes into play for electro-chemistry is current density, temp, ph etc. You really want fairly large electrodes for your setup. I am doing research right now, because I am also looking to make a Chlorate/sugar/Ammonium sulfamate/dye based smoke bomb for the fourth.

 

[Letda]

hey guys, I am new at all this so don't judge me right away. I'v been researching how to make the potassium chlorate for about a week now w/o actually doing a lab. I'v read everything that had been posted, but I am still a little lost. I was just wondering if one of you could break down the steps in lame'ns for me. I run an IQ of 147, knew frued before i knew freud, but chem... i sometimes wonder. If anyone can talk one on one with me to help me understand i might be of some value to your conquest. Just E'mail me at -letda13@hotmail.com-. otherwise ill be reading up on your findings and starting my experiments my self. Ill post everything i find i promise :)

 

[mrjeffy321]

Hello, I have been researching/making potassium chlorate for about 9 months now, so I have gotten plenty of experience by now.

Do you have any specific questions, or do you just want general information on the process(es).
Like redwraith94 mentioned, this is a popular time to start making KClO3, only about 2 weeks left until the 4th of July (and all the homemade fireworks that go with it [taking all necesary precautions of course]).
If you want to make a lot of Potassium Chlorate in a short amount of time, I would go with the decomposition of hypochlorite method (boiling bleach), but if you have more time and are patient enough, the potential for gain using the electrolytic method is much greater. I myself prefer the electrolytic method, but I have been plagued by bad luck with it also, using hypochlorite is certainly provides much quicker results (and some might consider it easier).
I actually have a batch of KClO3 drying right now.

 

[Letda]

I guess I’m kinda of an unusual person, I’m a psychology major with a weird fascination with astrophysiology and aeronomics, so I guess I’m not trying to make "just" fireworks for the 4th of July but I want to use concepts from these basic principles to further my know how in such matters...

So, when boiling the bleach, do you just boil until no liquid is left or do you get the crystals before that, and are they what I need in pyrotechnics? And I’m totally unfamiliar with electrolytic, is that just like putting a positive charge on one end of the cup and neg. on the other end? As you can see, at 17, I think I'm a little behind, I was too cool to take chem. serious in school... how sad huh!

 

[mrjeffy321]

The bleach boiling method is easiest to understand.
Bleach is a solution NaOCl (sodium hypochlorite), and generally it has a lot of other stuff in there too, I know that clorox bleach is 6% NaOCl, 5.63% NaCl, and .015% NaOH, and the rest it is just inert stuff and/or water. All you are concerned with right now is the NaOCl.
When you boil bleach, the NaOCl decomposes to form NaClO3 and NaCl,
3NaClO --> NaClO3 + 2NaCl
Sodium hypochlorite is very soluble in water (100 g / 100 mL), but sodium Chloride not so much by comparison. So the trick is getting the maximum possible amount of NaClO3 dissolved in the smallest amount of water possible and not have very much "other" stuff in solution, like NaCl.

This page,
http://www.wfvisser.dds.nl/EN/chlorate_EN.html#therm_starting
gives instructions on how to make chlorate both using electrolysis and thermal decomposition of hypochlorites.

You will see in those instructions that you are suppose to boil 1 L of 4% bleach down to 140 mL. If you do the math (and I have), you will find that this is a lot more than is really necesary to hold the amount of NaClO3 you will have left after decomposing the NaOCl. The reason is because there is all that other stuff in solution too. Actually, in practice, if you follow those instructions, there will be NaCl comming out of solution even before your done boiling.

Anyway, so now you have a solution of NaClO3 and some NaCl. But you wanted KClO3, not NaClO3! to turn the sodium chlorate into potassium chlorate, you can use a double replacement reaction between the NaClO3 and KCl. The potassium ion will push the Sodium out of the NaClO3 and replace it, and then the Na ion will join up with the Chlorine ion,
NaClO3 + KCl --> KClO3 + NaCl

After you do this, you should notice a white percipitate forming. This because unlike NaClO3, KClO3 is not nearly as soluble, not even close.
But to maximize yeild, we want to get all the KClO3 out that we can, so we cool the solution down to just around 0 degrees celcius, and then filter out the percipitate, which will be mostly KClO3 and some NaCl.


The Key to the whole reaction is that bleach (NaOCl) will decompose and form NaClO3, which can them be turned into KClO3.

the electrolytic method is much more complex, but is explained in the web page provided above.

 

[Letda]

I understand this a lot better than before, so thnx. But, where do you get potassium chloride, is that the salt substitute? and is the NaCLO3 worth anything in that form or must the Na be replaced with the K?

 

[mrjeffy321]

I buy my Potassium Chloride as a salt substitute, called, "NoSalt", there are also salt substitutes (I think called "LoSalt"), but these also contain a large part sodium chloride, you want to get the one with as much potassium chloride as possible.
Sodium Chlorate is in itself worth something. It will react very similar to KClO3, but because of its high solubility, it is hard to extract. a lot of the time in chemical formulas for pyrotechnic things, KClO3 and NaClO3 are interchangeable.

 

[Letda]

so let me make sure I am understanding this. When you boil the bleach, you get NaClO3 crystals after filtering the liquid, or is the liquide the NaClO3?

 

[mrjeffy321]

by boiling bleach, you make NaClO3 AND NaCl.
Since NaClO3 is so much more soluble than NaCl, most (or all) of the crystals that percipitate out will be NaCl, and the NaClO3 will remain in solution.

Then when you add KCl, you make KClO3 and NaCl. this time NaCl is much more soluble than KClO3, so most of the percipitate is KClO3 and then NaCl remains in solution.

 

[Letda]

Thnx,i just bought everything 10 mins ago so ill be testing everything tomorrow, ill let you knogw how things o. thnx for all of the help.

 

[Letda]

well, my first run was a complete and utter failure...all i got was a bunch of brown and black stuff. I filtered it out, added the KCl and recooked...same thing...and i got no noticable crystals the first time? i guess ill start round two here in a bit...any suggestions?

 

[Letda]

ok, i managed to get KCl pure crystals using the boiling process, but i don't know how the bleach is suppposed to work, i boil and all i get is a bunch of brown and balck crap. no crystals form, I am i boiling to much or not enought or what?

 

[mrjeffy321]

Are you following the instructions in the link I provided a couple posts back,
http://www.wfvisser.dds.nl/EN/chlorate_EN.html#therm_starting
I found if you follow these instructions pretty closely, you will have very good results, although some deviation can be made to see what works best.

You should boil the bleach in a pyrex / heat resistant glass container optinumy, definatly not metal.

 

[Letda]

i was using metal, it said stainless steel on the site if i remeber right. i guess ill get glass then. Ill get back to you when i use the glass.

 

[mrjeffy321]

I used to use stainless steel, and I kept getting some brown stuff in the mix while boiling. At first I thought it was a product from the reaction, although I couldn't explain what it was, and now I realize that it was most likely Iron Oxide being made when the bleach oxidized the Iron in the pan (my first clue is when it ate throught the pan and I had a big hole in it).

Glass is definatly best, although you need to be more careful with it. I use a old coffee pot that can take the heat.

 

[Letda]

i just bought some glass bake-ware, hopefuly if i don't heat it up too fast it won't shatter. I mean if all else fails... I have on old coffee pot of my own so i can further follow in the steps of my mentor...lol.

you wouldn't happen to have anymore vidoes would you? I'm curiuos to see what you've been doing with 9 months supply. =)

 

[mrjeffy321]

Any more videos? how did you know about those?...o wait, I remember posting those 2 videos to show the difference in flame color of the two batches of KClO3.
I do have a few more of some interesting stuff I did with the KClO3 (ending dramatically on Febuary 18th), but they are too large to show.

Now, I mostly just use it in small (less than 50 grams) pyrotechnic things. Right now, my stock pile is a little less than 200 grams of KClO3. Hopefully I can get my electrolytic cell up and working again.

 

[redwraith94]

I was going to try the electrolytic cell myself, but after reading one of the links that you posted mrjeffy321, I decided to do the bleach method instead. I have tried the electrolytic methid before w/ Sodium chloride, and never was able to spend money for proper electrodes, so it always ended up something that I wasn't happy with. I just bought a gallon of the cheapest bleach that I could find. I'll keep you guys posted on how it goes.