making potassium (per) chlorate

[MrB]

The other problem is you can't just use a computer power supply to power a perchlorate cell because I've tried it and fried a bunch of anodes... it pushes too little current at 5v and way too much at 12v (which would destroy most power supplies)

 

There is a bunch of other options, from which "other" power-supplies probably is the better route to go, but that said... You have, at least, 3.3, 5, 7, 8.7, 12, 15,3, 17, and 24v available from a PC power-supply, without modifying it. If you are lucky enough to have a ATX 1.0 power-supply, you would have 8.3, 10, and 17v as well. And if 5v isn't pushing enough, then 3.3v wont do you much good, and the same would hold true for the range above 12v. But 7, 8.3, 8.7 & 10v could all be in the right neighborhood as far as your post goes. I do however believe "most" systems run on 6.5-7v?

The main issue however, is that the cell voltage changes as the process moves along, to maintain the current. Whats really needed is a constant current power-supply, and while i suppose you could use a PC power-supply to feed a controller, it's probably cheaper to buy a combined unit to start with. LED power sources comes to mind. Which brings us back to where i started. Another power-supply, over a PC one, is probably a wise choice.

B!

Edited October 23, 2016 by MrB

[WSM]

I'm in the US, theirs just so much out there it's mind blowing. And some of which I have doubts on working. Kind of like all the videos on YouTube where colored smoke is as easy as crayons, sugar and KN03.

 

You can likely get potassium chloride water softening salt at either a grocery store or large home repair center such as Home Depot. I've found various types of DC power supplies, as well as MMO anode on CP titanium mesh material, on eBay for reasonable costs.

 

Making potassium chlorate is a simpler process than most others, and a good place to start. After you get started and realize a degree of success, you may wish to expand your efforts and try your hand at making other chlorates and even perchlorates. We will be here to cheer on your efforts and successes.

 

If you have questions or want to know more about particular parts of the process, feel free to ask. Several people here will be happy to give suggestions or assistance.

 

Welcome to the discussion.

 

WSM

Edited October 25, 2016 by WSM

[WSM]

perchlorates require anodes that are either expensive (platinum) and a pain to work with, or LD which could be cheap but nobody makes them commercially, so it means we'd have to make it ourselves and that requires some serious lab equipment. In the US it makes little sense since it's readily available so anyone doing it is only doing it to show they could do it. The other problem is you can't just use a computer power supply to power a perchlorate cell because I've tried it and fried a bunch of anodes... it pushes too little current at 5v and way too much at 12v (which would destroy most power supplies)

 

It's not that no one makes LD anodes commercially; it's that small, affordable lead dioxide anodes aren't offered for sale to the public locally. From time to time I see an offering in specialized publications or online, LD mesh anodes in small sizes. These are very specialized items and not large movers, so they're not generally seen on the open market.

 

It's not that they're unavailable, but that they're rare; so we need to be vigilant in our search for them (and please share when and where you find them) and don't give up.

 

As for platinum anodes, I've found some platinized titanium mesh on eBay for roughly $10 each, delivered, that are roughly 2" by 4" (or slightly more than 50 cm² per single side). They don't come with a lead, but that can be handled by any number of means. See eBay item number: 221992630862 for an example.

 

I've recently found variable DC power supplies that have CV and CC capability, for about $60 delivered. So, if you have or can make sodium chlorate for feedstock, making perchlorates is possible. How long these materials will work or how much material can be made, I'm unsure, but it is possible.

 

WSM

 

Edit: I should mention the platinum plating on these mesh anodes is fairly thin (about 5 microns if I remember correctly) and probably won't last as long as those with a thicker platinum layer. They may also make an excellent foundation for lead dioxide plating, if you're set up to do that. The main feature of these anodes is their low cost and worldwide availability.

Edited October 25, 2016 by WSM

[WSM]

There is a bunch of other options, from which "other" power-supplies probably is the better route to go, but that said... You have, at least, 3.3, 5, 7, 8.7, 12, 15,3, 17, and 24v available from a PC power-supply, without modifying it. If you are lucky enough to have a ATX 1.0 power-supply, you would have 8.3, 10, and 17v as well. And if 5v isn't pushing enough, then 3.3v wont do you much good, and the same would hold true for the range above 12v. But 7, 8.3, 8.7 & 10v could all be in the right neighborhood as far as your post goes. I do however believe "most" systems run on 6.5-7v?

The main issue however, is that the cell voltage changes as the process moves along, to maintain the current. Whats really needed is a constant current power-supply, and while i suppose you could use a PC power-supply to feed a controller, it's probably cheaper to buy a combined unit to start with. LED power sources comes to mind. Which brings us back to where i started. Another power-supply, over a PC one, is probably a wise choice.

B!

 

I've used several kinds and types of DC power supplies, EXCEPT a modified computer power supply, so I won't talk about them.

 

I've had experience with the type of supply mentioned as used for LED lighting systems. I've also been fortunate enough to find decent prices on a few variable output DC power supplies that have constant current (CC) capability.

 

Currently, on eBay, there are a few lab type, variable output DC power supplies available for about $60 US, delivered. For example, check out items numbered:

 

251705177148

272390875798

201639714502

282008777000

 

I haven't seriously investigated them yet, but most appear to have CC capability, which I've found be a factor in the success I've had in making sodium perchlorate.

 

Good luck.

 

WSM

[WSM]

There is a bunch of other options, from which "other" power-supplies probably is the better route to go, but that said... You have, at least, 3.3, 5, 7, 8.7, 12, 15,3, 17, and 24v available from a PC power-supply, without modifying it. If you are lucky enough to have a ATX 1.0 power-supply, you would have 8.3, 10, and 17v as well. And if 5v isn't pushing enough, then 3.3v wont do you much good, and the same would hold true for the range above 12v. But 7, 8.3, 8.7 & 10v could all be in the right neighborhood as far as your post goes. I do however believe "most" systems run on 6.5-7v?

The main issue however, is that the cell voltage changes as the process moves along, to maintain the current. Whats really needed is a constant current power-supply, and while i suppose you could use a PC power-supply to feed a controller, it's probably cheaper to buy a combined unit to start with. LED power sources comes to mind. Which brings us back to where i started. Another power-supply, over a PC one, is probably a wise choice.

B!

 

I forgot to mention, in my successful sodium perchlorate experiments last year, I ran the cells at between 4.2 and 4.9 Volts DC. Maybe in a larger system higher voltage might be the norm, but in my "proof of concept" experiments, the lower voltage worked just fine, plus with little observable wear to the electrodes. As with other chlor-alkali cells, the voltage has to be "just high enough", but the critical element is the current delivered.

 

I ran out of sodium chlorate, so hence my interest in making my own sodium chlorate feedstock from sodium chloride, since that time. The final goal is to produce high quality potassium perchlorate (pyrotechnics grade), to prove it's possible and practical if unavailable any other way.

 

WSM

 

Edit: plus I like the sense of being self sufficient for oxidizers, that it gives me.

Edited October 25, 2016 by WSM

[Visco]

So using a sodium chloride solution makes perchlorate when reacted with a potassium chloride solution? But only after it has run in the cell? And starting off with a potassium chloride solution makes chlorate correct? If so can the chlorate be decomposed thermally to make perchlorate? I have some more reading to do but think this is something I would like to persu in the feuture. I know a chemist friend that may be willing to help me since he also likes to experiment and likes to make his own equipment on the cheep.

[WSM]

So using a sodium chloride solution makes perchlorate when reacted with a potassium chloride solution? But only after it has run in the cell? And starting off with a potassium chloride solution makes chlorate correct? If so can the chlorate be decomposed thermally to make perchlorate? I have some more reading to do but think this is something I would like to persu in the feuture. I know a chemist friend that may be willing to help me since he also likes to experiment and likes to make his own equipment on the cheep.

 

Sodium chlorate can be electrolyzed to make sodium perchlorate, with the right electrodes and conditions. That sodium perchlorate (after being purged of any residual chlorate) can be converted to potassium perchlorate by adding potassium chloride solution.

 

Potassium chloride solution can be electrolyzed to directly form potassium chlorate (the easiest oxidizer to make in my opinion).

 

Swede proved it's possible to convert potassium chlorate to potassium perchlorate with a platinized titanium anode, but it's difficult and jams the electrodes with KClO₄ crystals as soon as they form.

 

Sodium chlor-alkali salts get more soluble as the oxidation level rises, where potassium chlor-alkali salts get less soluble as the oxidation level rises. This means that potassium chlorate drops out of solution as it forms, making for a simple, direct oxidizer production. Sodium chlorate is more soluble than sodium chloride and sodium perchlorate is more soluble than sodium chlorate. Even though potassium chloride and sodium chloride solutions have almost the same solubilities, sodium perchlorate is about 100 times as soluble as potassium perchlorate (which is why solid, powdered potassium perchlorate forms instantly when KCl solution is added to NaClO₄ solution).

 

There's more to it, but it's late, I'm tired and I have to go to sleep now.

 

WSM

[Arthur]

Commercially sodium salts are electrolysed because it's less damaging to the electrodes, which at the cost of platinum is important. When the reaction proceeds to the intended degree then the sodium ion is substituted for an other more useful ion. Also K perchlorates ppt out before K Chlorates which is another useful means of purifying the product.

[Visco]

I read an article where I believe potassium chloride solution was used to make potassium chlorate then it was heated or melted and held at a melted point for a while to kill the chlorate and became perchlorate. Is this possible? When using sodium chloride solution to make sodium perchlorate what exactly purges out the chlorate?

[greenlight]

I think I have seen a youtube video on converting chlorate to perchlorate with heat in a mini crucible before but can't remember the details...I beleive it is on chemplayers channel.

 

Here is photo of the inside of the power supply. I found one random bit of metal and I can't figure out where it came from but it looked like it caused the problem cause there is darkened burning around where it was touching. It is lying in top left of power supply box in photo. I also uploaded a photo of it and when I disconnected the wires I noticed one of the positives was black compared to the other still new looking copper one.

Edited October 24, 2016 by greenlight

[WSM]

I read an article where I believe potassium chloride solution was used to make potassium chlorate then it was heated or melted and held at a melted point for a while to kill the chlorate and became perchlorate. Is this possible? When using sodium chloride solution to make sodium perchlorate what exactly purges out the chlorate?

 

I've heard that too, but the perchlorate formed by heat is impure (KCl contamination) and low yield for the energy input.

 

To destroy the residual chlorate in the sodium perchlorate solution, the common method involves bubbling SO₂ gas through the solution. The simplest method uses sodium metabisulfite solution injected slowly, deep under the surface of the electrolyte; to keep the sulfur dioxide gas in the solution where it destroys the chlorate, but leaves the perchlorate alone, plus the residue remains dissolved when the sodium perchlorate is converted to potassium perchlorate (which drops out of solution immediately) by metathesis through adding KCl solution.

 

WSM

Edited October 25, 2016 by WSM

[WSM]

Here is photo of the inside of the power supply. I found one random bit of metal and I can't figure out where it came from but it looked like it caused the problem cause there is darkened burning around where it was touching. It is lying in top left of power supply box in photo. I also uploaded a photo of it and when I disconnected the wires I noticed one of the positives was black compared to the other still new looking copper one.

If I'm seeing it clearly, it looks like the fuse is blown. Now that you've removed the metal piece shorting the power supply, you may want to replace that fuse and see if the power supply functions properly.

 

Good luck.

 

WSM

Edited October 25, 2016 by WSM

[TomasBrod]

I must have really bad luck or my MMO is bad. I set up another cell 47hours ago, smaller one, a bit less than a liter.

With 55x37mm anode mesh area submerged and the failed mmo from previous run as cathode.

This time I took care and bought salt that explicitly says no iodine. I dissolved it in distilled water and filtered

some insoluble (probably the anti-caking agent). Current demand was calculated 6.1A and

at 4.5V 5.7A was flowing. Then only after 47 hours current slowly dropped to 3A and going down.

After the initial chlorine production phase, only very could be smelt. Liquor is clear.

I bumped the voltage a bit. We will see how it goes.

And good luck with the power supply Greenlight.

[Visco]

Sorry for all the questions. So is the sodium metabisulfate injection taking place during or after the time in the cell? I only ask these questions because I know it's not as easy as some reading and videos make it seem. It's not about making someone else do the hard work to my benefit. I'm just trying to learn as much as I can before I dive in with both feet.

[greenlight]

Thanks guys I will have a look tomorrow at the fuse.

 

@visco, I believe the sodium metabisulfite injection is done after you have converted most of the chlorate to perchlorate. So after the run right before you double decomp with potassium chloride.

I know what you mean, I have been trying to figure out how to go all the way to perc for a while now and only just started actually trying to run the cell

[Mumbles]

You may also want to check the fuse in the bottom right of your picture. I can't tell from the image entirely, but it looks fairly cloudy and like it may have burned out. It could just be dirty too. They're a cheap fix luckily if that is one of the issues.

 

The thermal decomposition of chlorate into perchlorate is not a particularly viable route. It's not a clean or efficient or very high yielding reaction. The temperature must be closely controlled to prevent it from going too far and producing potassium chloride and oxygen instead. In all actuality, you can't have one without the other. Both pathways are simultaneously active. At least the side-product is potassium chloride in both cases, which simplifies the cleanup at the end. If you want a useful quantity of perchlorate electrolysis of chlorate is really the only way.

 

To destroy residual chlorate from perchlorate, sulfite or bisulfite is regularly used. While a one shot chloride to perchlorate method would be ideal, the conditions on a home scale have not yet been worked out. As of right now, it's better to go chloride to chlorate, do an intermediate cleanup, then electrolyse chlorate to perchlorate and do another cleanup.

[Mumbles]

Oops, missed the second new page of replies. Looks like everything was basically covered already. It's always reassuring when someone like WSM agrees with you on something like that fuse as well.

 

This is a complex topic. There are some 200 odd pages to this thread which are a goldmine if you want to look through them. I also suggest WSM's and Swede's blog entries.

[Maserface]

I am looking into a solution for the "unavailable" LD anode problem; I will make them available on the forum if/when I have it sorted out.

[WSM]

I am looking into a solution for the "unavailable" LD anode problem; I will make them available on the forum if/when I have it sorted out.

 

 

Excellent!

 

If you get both LD on titanium mesh AND LD on graphite, I'll be your first customer !!!

 

You are looking for hard crystalline, beta form lead dioxide, right? I think that (the BfLD) crystal pattern lends itself to the best (and longest lasting) perchlorate anodes available.

 

WSM

Edited October 25, 2016 by WSM

[Visco]

What would be the optimum size of a lead dioxide anode for a home perchlorate cell? And what would be the optimum thickness of the lead oxide coating? I've never made perchlorate and want to and may have found a supplier and need to know about these things to get a price for manufacture. Edited October 28, 2016 by Visco

[taiwanluthiers]

I think a normal 2" x 6-8" anode size is good, as for coating thickness it does not need to be really thick... ones I seen aren't more than .5mm thick.

[Arthur]

If you have found a good reliable supplier we'd take a standard size from them! Even if we create the standard! 2" by 2" would be a minimum, 3" x 9" would be a maximum.

 

Realistically the few who want a big cell could put two or three anodes and cathodes into a bucket cell lid.

[WSM]

taiwanluthiers and Arthur are both correct.

 

The two sizes I currently have are 2" by 6" and 4" by 4" (or 50mm by 150mm and 100mm by 100mm). They're beta form (hard crystalline) lead dioxide on CP titanium mesh. I used the 2" by 6" anode for my perchlorate experiments in June, 2015 and it worked beautifully. When I harvest a large enough stock of NaClO₃, I plan to try my other LD anode as well as a couple different platinized titanium anodes I've purchased.

 

I'm sure we can adapt whatever lead dioxide anode becomes available to electrolyze chlorates to perchlorates. The nice thing about smaller anodes is that the current demand will be modest, and a smaller CC capable, variable DC power supply is so much more affordable than larger units (+- $60 US).

 

Let's see what Maserface is able to find.

 

WSM

[Visco]

I will contact them today about the anodes I myself was thinking 2"x6". No guarantee but I will try my best and see if it works out. That's all I can do.

[WSM]

What would be the optimum size of a lead dioxide anode for a home perchlorate cell? And what would be the optimum thickness of the lead oxide coating? I've never made perchlorate and want to and may have found a supplier and need to know about these things to get a price for manufacture.

 

Hi Visco,

 

I don't mean to chastise you, but for your information;

 

The lead oxides available are numerous and we need a specific one for the most effective use on our anodes. By saying lead oxide, it's usually inferred to mean lead monoxide or litharge, which is not what we want. Lead dioxide (PbO₂) is called for, and even then, not just any lead dioxide; but the beta lead dioxide which has a hard crystalline form and works the best (and longest lasting) in perchlorate cells.

 

If we keep our terms accurate, we'll avoid confusion and communicate clearly.

 

WSM