What Went Wrong in My Attempt to Make Potassium Chlorate?

[Letda]

well, i just wanted to let you know the glass worked wonders and i got exactly what i was looking for but...in the midst of all of my happiness, while cooling off...it shattered. i was so disappointed to say the least. Now i can't find anything anywhere to use that's glass and can go on the stove. if you know of anybrand or place to buy it i would be more than happy to hear about it.

OH, and good luck to you redwraith94, its kind of a pain in the butt, but I am sure youll have no promblems once you get going.

 

[mrjeffy321]

but...in the midst of all of my happiness, while cooling off...it shattered.

Oh no, I feel your pain.

Like I said before, I use an old [easily 15 to 20 years old] coffee pot, and as long as I treat it carefully, it works very well. Now-a-days, I don't think they make coffee pots as good as used to, a lot of the ones I see say specifically not to boil water in them, and others NOT FOR STOVETOP USE.
Supposidly, Pyrex brand glassware is good for this type of thing, but even that must be made in different "Grades" of heat resistivity because all the pyrex I see in the store has that "Not For Stovetop Use" warning on them.
there are laboratory glassware peices designed to withstand high temperature conditions, that might be a possibility.

 

[Letda]

My experiments are going to be post-poned for today at least, and probably tomorrow due to an unexpected direct assult from the flu virus...lol. but, not to worry, progress will presume soon enough and you'll know all aoubt it.

 

[redwraith94]

Normal glass is mostly SiO2 (Silicon Dioxide) with a lot of other impurities/color additives as well. Pyrex has B2O3 (Boron Oxide) as an additive.

The thing is that B2O3 expands ALOT less than normal glass (SiO2 + whatever...Na...K...Ca...etc.) so the more Boron in the glass, the less it expands when heated, and the less it contracts when cooled. Since the glass moves less it produces much less internal stresses, which is why lab grade pyrex can usually be heated w/ a propane torch, or a bunsen burner w/ no problems @ all.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=26237&item=7526217836&rd=1&ssPageName=WDVW

This is one that I will probably buy when I get paid since it will hold an entire gallon of bleach @ one crack. I am not sure if this can be used stove top though, I will have to check w/ the seller first, and you probably should too if you go to buy it.

 

[mrjeffy321]

You want to boil an entire gallon of bleach in one batch?
When I use the boiling method to make chlorate, I usually use 1300 mL of bleach (which is all my coffee pot will hold without overflowing when it boils), and it takes quite a bit of time to boil all the excess water away and process the remains. From when I begin to heat the bleach, until when I put the KClO3 solution into the freezer, it takes about 4 hours. Given most of the time is waiting for the liquid to boil and then cool down, but an entire gallon, WOW, someone is patient.

 

[redwraith94]

Yeah, if you think that is patient, wait till you here how I made my first batch. I actually used a pyrex glass bread pan (not lab grade) and put it in the oven until all of the water boiled off. I had to do six batches for the entire gallon.

 

[mrjeffy321]

So, Letda, have you gotten any results yet, give up, still sick?


A [long] while back in this thread, I think I mentioned something about a program thatr could calculate the run time of an electrolytic chlorate producing cell. The program I am/was referring to is here (at bottom of page),
http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/table54.html
As great as this program may be, I think it leaves a lot to be desired, so I decided to make my own.
Here is the link to a website that you can download (283 KB) my program's install file so you can test it out yourself, I assure you it is safe, there is no virus, spyware or anything bad, it is totally safe.
http://www.geocities.com/platapus453/Chlorate_Cell_Setup.zip
I would like for you all to test it out, tell me what you think of it, and possible give me some sugestions on how to improve it.
I personally think my program is wonderful just as it is, but I am looking at it through the eyes of a programmer and I marvel at some features I added that are taken for granted or expected in programs today.

***please note, since this program was written in Visual Basic .Net, it requres that your computer have the .Net framework (version 1.1) installed on your computer, which can be downloaded free from Microsoft***

 

[Cesium]

Alright, I have joined the quest to make potassium chlorate. I have decided to do the electrolysis of NaCl and then precipitation with KCl. I have a small batch precipitating now and I think it is working. Assuming I get KClO3, what ratios do you suggest for burning it with sugar? Anybody else try any cool things?

And also, How do you "manually" find out the amp-hours? I think I can only measure volts.

Thanks in advance.

 

[mrjeffy321]

I personally like the weight ratio of about 3 parts Chlorate to 1 part sugar (sucrose), or to be more precise, 2.86 KClO3 to 1 C12H22O11.
The more complete of a combustion you set it up to have, the cleaner it will be (ie. less smoke), you don't want too much/any excess sugar because when/if that starts to burn, it makes a lot more smoke and leaves a dark residue behind.
I have tried lots of "cool things" with KClO3, many of which included rocketry [notice the past tense]. Then on Feburary 18, 2005 (a date etched [or rather exploded] into my memory), I found out how dangerous the stuff could be.


Measuring the amp hours through the cell is very critical, it will determine how long you should run the cell and how much Chlorate you can expect to get. There are two basic method of measuing amp hours, either directly with a meter (an amp hour meter, which I tried and failed at building [unless someone with electrical skills wants to help ]), or indirectly through taking measurements and keeping a tally. Since I don't have a meter, I have been forced to do it the hard way, measure the current (amps) through the cell with an ammeter, then from that, I estimate an average current for that period of time, which I then can get my amp hour reading from. It is a hassel if you want to do it correctly. The more readings you can take, the more accurate you will be, and when you have to estimate, round down, not up, it is better to put too many amp hours through the cell than not enough.
I recently had an idea about using a watt hour meter as an amp hour meter substitute. Since power (watts) is equal to Volts * Current, and watt hours is power * time (time being in hours), if you divide watt hours by the average voltage through the cell, you should get amp hours. But I can't find any watt hour meters that will measure DC current in a reasonable price range.

 

[Cesium]

I have a multimeter and it only measures volts and ohms. Guess I need to buy an ammeter now.

I am guessing that the current changes by itself as more chlorate is produced. Otherwise you wouldn't have to keep on recording values. If you have a constant source of power and the cathode-anode spacing remains the same, the current wouldn't remain the same also?

 

[mrjeffy321]

Using Ohms law,
V = R*I
Volts = Resistance * Current, if you can measure volts and ohm, then you can determine the current.
However, I don't trust multimeters to measure resistance for me, ESPECIALLY through an electrolytic cell. I would recommend getting yourself an amp meter (preferable one that can meaure high currents, atleast a couple amps).
In a perfect world, the resistance through the cell would remain the same and that would make things much easier. But in reality, the resistance depends on many things, electrolyte concentrate (the solute and solvent will varry as the cell ran), temperature of the cell, temperature of the wires, ... .
The current will change all the time, atleast in my cell it does, sometimes you'll be lucky and it will stablelize for a while, but most of the time it will fluctuate (not drastically, but enough to make a difference).
What is your power source? Make sure it can handle outputting several amps of current if you don't plan on waiting a month for the cell to be finished, the higher the current, the less time you have to wait.
Side Note:
I ran my cell for the entire month of Febuary (1st through 28th, not continuous mind you), I put 653 amp hours through the cell, and I made a total of 140 grams of NaClO3, which gave me an efficeny of 28.3%, quite pathetic. I hope to hear some better results from you.

 

[Cesium]

Yes I have read extensively about your successes and failures. You sure have stuck with it though!

My power source is a battery charger for a drill. It's great because I get a constant flow going without batteries dying and whatnot. It gives 3.5 volts, no clue how many amps. I read on one of the sites that was linked here that 3-4 volts was recommeded.

What do you think about using several anodes and cathodes? Wouldn't the amperage increase by using 2 or more power sources connected to different sets of electrodes in the same cell?

Also, what color is your solution normally after you have run it for a day or so? On one unsucessful attempt it was brownish-yellow because of all the saturated chlorine and hypochlorous ion (I think). This time it was pretty much clear with particles of graphite flowing around.

Thanks again for all your help!

 

[mrjeffy321]

Yes I have read extensively about your successes and failures. You sure have stuck with it though!

I like when people appreciate my work, it makes all the log taking and number tallying worth while. I seem to have become somewhat of an expert on a certain, specialized, topics here.

The power souce is outputting just the bare minimum need for the reaction to occur,
"The supply must be a DC supply with a current capability of at least what you want to run the cell at and a voltage above 3.5 volts (more if you are making perchlorate)." - source
So technically, it would work. Keep in mind, as I said before, the more amp the better, and current is dependent on voltage (V = R*I), so assuming the resistance in the cell stays roughly the same, the higher the voltage, the higher the current. I use a computer AT power supply, I switch back and forth from using the +5V (gives me about 2.5 amps) and +12V (gives me about 8.0 amps) outputs. In this type of cell, I don't thinking having an over voltage will hurt any (until you get down to less than 10% chloride, then you'll start making per Chlorate).

Using more electrodes will increase the current since the combined surface area on the electrodes is greater. I use carbon-graphite electrodes which erode away slowly through use. It is good to have a very low current to surface area density on the annode (+) in order to slow the erosion, however the cathode (-) doesn't seem to erode at all, or atleat non-noticeable amounts. So using several annodes will help reduce the current density, but it will also help distribute the chlorine production thoughout the cell, thus increasing the amount of chlorine dissolved in solution. With less of the chlorine escaping into the atmoshere (besides making it better for you), it will dramtically increase efficency. I wouldn't recommend using multiple cathodes, I don't see the need, if you have the spare electodes, use the for extra annodes if anything (or spares for when one is used up).
Uisng more than one power source on the same cell is tricky and I don't recommend it. For one, it is easy to burn out a power supply that way (I have done it), also, it doesn't seem to help that much I find. You would only need to have one ground connection to one cathode, but then you could have multiple annodes connected to the outputs of several powers supplies, but this makes the total current harder to measure.

Since I use carbon-graphite electrodes, after a day of running it, my solution is as black as the nigh (especially if I use high current most of the say). If I filter the carbon out, then I am left with a yellowish liquid that looks and smells like bleach, because it is. I can then boil that down to decompose the hypochlorite (which I need to do the take a pH reading with my litmus paper), and then it becomes much cleater - almost transparent.

Have you or anyone else had a chance to look at my program to calculate the running times for a chlorate electrolytic cell (mentioned about 6 post back)? I am eager to get some user feedback on it to see how I can improve it.

 

[Letda]

yeah, iv been gone a while...sorry. I have to admit I've almost given up. I have been through 2 more glass "pots", and they keep shattering on me...its extremely frusturating. I'll try again in a few more days, [i have to work mornings now...:-(...so]. and If i break another glass i think I am going to try the electronic method...

 

[Cesium]

Nice work! I downloaded your program today. It's going to be really useful. There's no way I can really tell yet if it is accurate though. Once I get an ammeter, I am going to test it out. I'm going to see what my yield is and then calculate the efficiency of my cell using that.

 

[mrjeffy321]

I first got the idea for the program from this site (program link at bottom),
http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/table54.html
the two programs give the same ansers, so either we are both wrong, or both right.
In the program, I found out how much charge must be used to convert x amount of chloride to chlorate, I believe it is 6 faradays per mol of chloride converted, then it is simply a matter of adjusting for efficency (I think if you just leave the cell alone and not try to adjust pH or anything, you average about 50%, so that is the default efficency in the program).

 

[jeffomatic]

I make potassium chlorate by electrolyzing "diet salt". I use a 1 quart stainless steel kitchen pot with a glass lid that has a hole in the middle, left after removing the plastic knob. I made an anode holder that fits in this hole. I use battery carbon for the anode and a hefty battery charger for the source of DC. I mix a concentrated solution of the diet salt, then start the charger on the lowest (6 volt) setting. I adjust the depth of the anode to get 4 amps and let it run for 24 hours. The I filter the solution and boil it for a while and set it in the fridge. The potassium chlorate crystals will precipitate first. The solution decanted can be returned to the electrolyzer and more salts and water added for another batch. The crystals can be washed with ice water to clean them, then re-disolved in hot water, boiled and crystalized again to purify them.

The diet salt works great, it is a mix of half NaCl and half KCl. The only trouble is that it contains iodine too. It takes extra filtering, as it turns the whole solution dark reddish brown. I filter the iodide out with a cloth filter in a funnel, followed by a toilet tissue wad in a funnel to get more of it out. The iodine forms a dark brown glop which filters out reasonably well, but the filtered solution is still somewhat yellow.

Don't get copper or other metals in the chlorate because it can make it unstable. I only prepare it in small amounts because of the potential for instability. I store it in the fridge with a loose-fitting lid. Don't mix KClO2 with things until you are ready to use it, especially sulfur. Assume all mixtures using chlorates can be impact sensitive, so don't tamp them into any container. Read all you can about hazards and mixtures before messing with chlorates!

 

[mrjeffy321]

The diet salt works great, it is a mix of half NaCl and half KCl. The only trouble is that it contains iodine too.

Don't mix [KClO3] with things until you are ready to use it, especially sulfur.

I don't think using diet salt is the best idea, since you have both NaCl and KCl, you will be making KClO3 as you are electrolysizing the solution. Since KClO3 isn't very soluble, it should percipitate out, so when you filter the dirty solution, you should be loosing some of your product. I still think it best to use just plain (cheap) NaCl to make NaClO3 first...then turn it into KClO3.

You salt has iodine in it? I have got to get me some of that. No, more likely than not, it has Potassium or Sodium Iodide in it, and a very small percentage at that. I think ordinary salt has about .02% NaI by weight, I am not sure about your brand of diet salt, but I can't imagine it is too much higher since in reality, the body doesn't need but just a very little amount.
However you seem to be descirbing that you find iodine crystals/blobs in your solution, implying that there is a lot of Iodine being make, perhaps from alot of NaI in your salt. Does it have a list of ingrdients or something on the side with the % of everything?

You shouldn't be mixing KClO3 with sulfur anyway, don't even bother being careful because you shouldn't put yourself in that situation.
But yes, you need to always becareful when mixing KClO3 with a fuel to burn with, but I have found that KClO3 and sucrose is reasonaby safe/stable to be stored (not that it is a good idea to make a bunch and let it sit just to test the theory). In other words, don't mix it until you want to use it.

 

[gravenewworld]

seriously, what is up with this thread? why doesn't it ever die?

 

[mrjeffy321]

seriously, what is up with this thread? why doesn't it ever die?

Its no longer a thread, it is more of a steel cable now that it has grown to 9 pages long, granted there are longer threads out there, but this one is my favorite for some reason.


And by the way, as long as I am posting, I might as well post some useful KClO3 info pertaining to my experiments.
I have run two more trials in a newly designed cell (actually 2 separate cells but the same design). I have the electrodes positioned at the bottom sticking up through the solution with an open top.
On the first trial with the new cell I had some...interesting...results.
I have 220 grams of NaCl in solution with 600 mL of water. I began assuming 55% efficiency, so I needed to put about 800 amp hours through the cell. Then about half way through the trial, something happened, I don’t know what, but I must conclude it had something to do with my graphite anode eroding away and the solution turned green-ish brown and it wouldn’t filter out. I ended the trial, and long story short I think I had some copper compound that was some how introduced. I ended up making 58.7 grams of slightly off-white colored KClO3 after 403.1 mp hours, giving me an efficiency of about 40%.

After the above trial, I found my cell leaked for some reason, so I rebuilt it new, using the same design, then only difference was that I made a slight change to the electrodes. I greatly increased the surface area of the anode (about double the previous SA) and soaked it in linseed oil for 5 days, let it dry and then installed it in the cell. I had much better results. I did a smaller trial so I could get finished quickly to see how well my changes worked.
I assumed 50% efficiency at the start, dissolved 80 grams of NaCl in 500 mL of water and passed 170 amp hours through the cell. This time the new anode worked wonders, much less (but still considerable) amounts of graphite powder was left in the water and less visible erosion was detected. I ended up making 56.2 grams of KClO3, giving me 43% efficiency. However, this entire trial was designed to be a very quick and dirty experiment to test the new cell and anode design, I didn’t even worry too much about pH control, I am very pleased with the results.

I usually don’t bother to purify my KClO3 after I filter the precipitate out of the solution the first time, causing it to burn with a yellow color (instead of the purple color it should have), but since I got an off-white KClO3 in the first trial I mentioned in this post, I decided to try it.
The color improved, it became much cleaner, but still not the snow white I am used to getting, and it still burned with a yellow flame, so apparently the purification process isn’t fool proof, but what I might do is take maybe 100 grams of the "good" stuff I have just sitting around and try to purify that. I would prefer the purple burning powder, but for what I use it for, the color doesn’t matter much.

 

[dx/dy=?]

Keep it up mrjeffry.

Your perserverance is inspiring.

 

[Cesium]

I'm wondering what thoughts anyone has on preparing KClO3 with K2CO3, described here: http://www.frogfot.com/synthesis/chloratedisprop.html

3K2CO3 + 3Cl2 ==> 5KCl + KClO3 + 3CO2

Ways of making K2CO3:

Fractionally crystallize K2CO3 from Na2CO3 and K salt or

5C12H22O11(s) + 48KNO3(s) => 24K2CO3(s) + 36CO2(g) + 55H2O(g) + 24N2(g)

HIGHLY exothermic and often does not go to completion.

Or make NaClO3 first from Na2CO3 then add KCl to get KClO3

Or can K2CO3 be purchased?

Thoughts, problems, or experience are appreciated.

 

[mrjeffy321]

I don't know anywhere off hand to get any Potassium Carbonate, but perhaps it could be obtained by heating baking soda (Sodium biCarbonate) to make Sodium Carbonate, water and Carbon Dioxide.
Then using a double replacement reaction with KCl, turn the Na2CO3 into K2CO3. Sound good?
I don't like the idea of burning Sugar and Potassium Nitrate to make K2CO3, for one because it is unnecesarily exothermic (it makes for an impressive reaction, but why burn something just to get the byproducts), also, as you stated, you are assuming the combustion is 100%, which we know it will not be, therefore you'll have a bunch of other stuff mixed in with your K2CO3

How do you propose to make and bubble the chlorine through the heated solution? This method seems a little complex and time consuming doesn't it, especially since you making 5 times the number of moles of KCl in the reaction as you are of KClO3.

if you try it, I would love to hear the results and your impressions.

 

[Cesium]

Mainly just throwing it out here because this thread is the ultimate source for all questions dealing with KClO3. I guess I am just frusturated with the difficulty in predicting the yields of NaClO3 by electrolysis of salt and the amount of variables that are involved. But then again, my power source is sucky and I still don't have a multimeter, so I haven't really given it my best shot.

Cl2 would be generated with sodium bisulfate (or any acid) and bleach. I did this as a test and it made LOTS of chlorine gas with tiny amounts of each reagent. If you ever need chlorine do this.

 

[mrjeffy321]

While I am thinking about it, let me just post my results from my recent purification of the "impure" KClO3.

I started with 100.0 grams of KClO3. it had enough [Na] impurities so that when it combusted with Sugar, it was yellow rather than violet.
I dissolved it in about 200 mL of boiling water, le it boil for a little while, then cooled it. Afterward, I stuck it in the freezer overnight only to find that it had frozen solid (which doesn't lend itself to easily filtering out the percipitate) so I had to thaw it and then cool it back down in the refrigerator and then briefly stick it in the freezer.
By the time I filtered it, the solution was somewhere between the highly scientific temperature range of "refrigerator" and "freezer" temperature.

I filtered it, dried it, and weighed the KClO3 extracted back out to be 81.5 grams. When I combusted it with sugar, the light it gave off was very bright more than anything really. There was still some yellow, but it had shifted considerably towards bright white and perhaps just the faintest of hints of violet. So I ended up loosing about 20 grams of KClO3 in order to make some slightly more pure, but hardly noticible, KClO3 cystals.

 

[Cesium]

Keeping this thread alive!

I am happy to report that my first proper attempt at making potassium chlorate was a success. I pretty much used the most OTC methods possible so my cell wasn't too great. 70g NaCl in 200mL water with a graphite anode (from old lantern battery) and stainless steal (4" cap screw) cathode in a polypropylene container. Electrodes were usually around 2-5cm apart and I tried to keep the temperature around 40-50C. Electricity came from a computer power supply of course at 12V (way too much I know...should have hooked multiple smaller cells in series but I only thought of that three-quarters of the way through!) and the current averaged 2.11 amps. HCl was added once or twice a day, but I didn't bother to measure pH. The cell was run for 115.9 hours for a total 9.14 faradays; this corresponds to a 56% efficiency. Of course, the standard horrible and yucky way of logging the amps periodically was used to calculate the approximate charge. This was the only part of the process that was at all annoying...the rest was easy and quite enjoyable

The jet black solution filled with the graphite sludge of several anodes was filtered three times and then boiled to destroy residual hypochlorite. At this point I had a yellow solution (Fe+2) tinted brown due to collodial graphite that could not be removed by filtration. I added 65g of KCl (salt substitute) to 250mL of water, mixed the two solutions, boiled the mix down, and began crystallization. This crop of needle-like crystals were discolored yellow and green due to iron and chromium impurities, respectively (and probably some graphite too). I then redissolved and recrystallized them, washed them with ice-water, and dried them in a toaster-oven. I ended up with about 48 grams of a nearly perfectly white powder which is a 46% yield. Not too great, but I think I actually needed to run the cell longer.

This is probably the only section of my post that merits a response. The stuff burns with a nice lilac flame, but it tests positive for chloride ions when silver/copper nitrate is added (a white precipitate forms). The flame color, however, indicates that they are very few sodium ions in the product. I guess there could be KCl but doesn't make too much sense due to its higher solubility. There were some other impurities listed in the salt substitute (calcium or magnesium silicate and something else that I can't remember) so perhaps this is what is precipitating. Or else there are just so few Na+ ions in there that there are overpowered by the K+? This is doubtful because flame tests are very sensitive to sodium ions...odd.