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ManyInterests
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Sodium perchlorate synthesis issues
I know what you're thinking: Didn't you use the search option? Well I did, and I didn't find what I was looking for, so I decided to make a thread
about the matter.
My first foray into chemistry was making chlorates, I wasn't thinking about perchlorates at the time, but seeing how ammonium perchlorate is very
useful in many applications, I wanted to expand into that. Back in 2022 I worked with Naruchan (AKA MysteriusBhoice) to make both sodium and potassium
chlorate, and while my yields were not good, the results were fantastic. I made a good deal of extremely pure chlorates and I meticulously noted the
processes, pH control, and everything. Then I wanted to get into perchlorate synthesis. I originally had a platinum electrode to use as an anode, but
it failed half-way in the synthesis. I did succeed in making some perchlorates, but clearing it away from the remaining chlorate was very difficult,
but I ultimately succeeded. I made some ammonium perchlorate with that and it did work in making things like iNAP which I have used, so I know it is
at least 'good enough'.
After that I was just tired of chlorates and perchlorates and decided to move onto other things. I wanted to come back to the matter earlier this
year, I even made my own PbO2 electrode from my no longer needed MMO electrode, but I did not use it. I instead opted to buy a PbO2 electrode, but my
choice could have been better (I should have bought from Feanor Forges from Ebay, maybe I might end up doing that later).
So here was my setup: I used 550g of sodium chloride in a 2000ml 3.5g/l sodium persulfate (made from ammonium persulfate via double displacement)
solution and I setup my electrodes 2.5cm apart. The PbO2 anode in the middle with the titanium on the sides. I used clamps (amateurish, I know, but
MysteriusBhoice and I found that useful), I ran it for around 92 hours total with an temperature range between 45 and 58C and the voltage was never
below 5.4, and the amperage peaked at 25, but did start to drop at the end. I replenished the liquid as it evaporated with more 3g/l sodium persulfate
solution.
I decided to filter it from the corroded PbO2 metal and I added some Methylene blue, which should turn purple to indicate the presence of
perchlorates, but no color change happened. It remained blue. I am lead to believe that I most probably have chlorate solution and not perchlorate.
How pure are the chlorates? Not sure yet, but I still got plenty of sodium chlorate from the 2022 synthesis.
So now that I shared my experiences thus far, what can I do to improve things? I would really like to be 'good enough' at making perchlorates as I am
chlorates. Where did I go wrong? Was the current too low?
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Deathunter88
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Look up how to do the methylene blue test properly, you need to strongly acidify the solution with HCl first.
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Radiums Lab
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Why don't you use KCl? It is better at turning into KClO4. KClO4 is less hygroscopic too.
Water is dangerous if you don't know how to handle it, elemental fluorine (F₂) on the other hand is pretty tame if you know what you are doing.
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ManyInterests
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| Quote: | | Look up how to do the methylene blue test properly, you need to strongly acidify the solution with HCl first. |
I was not aware. Thank you for telling me about that. I am assuming that this link (http://www.chlorates.exrockets.com/tests.html) will have sufficient information? It does not mention HCl for perchlorates though.
| Quote: | | Why don't you use KCl? It is better at turning into KClO4. KClO4 is less hygroscopic too. |
Because I remember making potassium chlorate and sodium chlorate... the sodium chlorate was so so so so much easier than potassium chlorate.I figured
the same would be for perchlorates, and since the starting reagent for sodium chlorate and perchlorate is the much more easily and cheaply obtainable
sodium chloride I figured I would go that route, and if I want or need potassium perchlorate, I can make some from sodium perchlorate via double
displacement with KCl (and I have a good deal of KCl on hand). This is my interest in making sodium perchlorate. Because I want to turn it into
ammonium perchlorate mostly.
But I need to mention a development in what happened... I dried all my stuff and I decided to do some simple burn tests. I made a 50:50 mixture with
sugar and it ignited readily. the fire wasn't too strong or quick, and it did leave behind a lot of residue... but then I decided to do a different
test. Since chlorate/sugar mixtures readily ignite when exposed to sulfuric acid, and I was told that sodium perchlorate/sugar mixtures do not, I
decided to try... and I made another 1 gram mixture and put a few drops of sulfuric acid. I heard some crackling and spitting, but no fire. I then put
on a few ml of sulfuric acid (pure stuff, not drain opener, BTW) and still no fire. It did crackle, turn a little yellow, and have a putrid, toxic
smell (I had to turn on all ventillation to get rid of it and I felt it for a bit).
I did hear that added sulfuric acid to sodium perchlorate will result in sodium sulfate and perchloric acid. Am I correct? Maybe I DID succeed in
making some sodium perchlorate? Or maybe it is all sodium perchlorate?
I need to know what tests I can do, and If a good deal of IS perchlorate, I need look up on http://www.chlorates.exrockets.com/chlorate.html to follow the steps to fully destroy all remaining chlorates that do exist so I can make some
good pure ammonium perchlorate! 
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woelen
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Based on the results of your test with H2SO4, I think that you have perchlorate, but with quite some chlorate impurity.
If you have pure perchlorate, then no yellow color is observed at all, when H2SO4 is added. The yellow color is due to formation of HClO3, which
quickly decomposes, one of the decomposition products being the deep yellow ClO2.
Try adding a few drops of H2So4 to your powder, without any sugar in the mix. If it still turns yellow, then you certainly have chlorate in it.
The fact that it does not ignite immediately means that it is not mostly chlorate. The remainder most likely is perchlorate (or less likely,
chloride).
Is your mix hygroscopic? NaClO4 is extremely hygroscopic, and obtaining dry crystals of this is very difficult.
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Alkoholvergiftung
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Couldn t you use the Aceton purification methode? Sodiumperchlorate is soluble in aceton chlorate not. If it disolve you can be sure its Perchlorate.
[Edited on 22-10-2025 by Alkoholvergiftung]
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Radiums Lab
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I always suggest you to make KClO4 because it's less hygroscopic and it's easy to store. The solubility at room temp is less but if you heat it enough
it's pretty soluble, purification is easy and ion exchange reactions are pretty easy when KClO4 is used compared to NaClO4, advantage of NaClO4 is
it's better solubility.
Water is dangerous if you don't know how to handle it, elemental fluorine (F₂) on the other hand is pretty tame if you know what you are doing.
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ManyInterests
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| Quote: | Based on the results of your test with H2SO4, I think that you have perchlorate, but with quite some chlorate impurity.
If you have pure perchlorate, then no yellow color is observed at all, when H2SO4 is added. The yellow color is due to formation of HClO3, which
quickly decomposes, one of the decomposition products being the deep yellow ClO2.
Try adding a few drops of H2So4 to your powder, without any sugar in the mix. If it still turns yellow, then you certainly have chlorate in it.
The fact that it does not ignite immediately means that it is not mostly chlorate. The remainder most likely is perchlorate (or less likely,
chloride).
Is your mix hygroscopic? NaClO4 is extremely hygroscopic, and obtaining dry crystals of this is very difficult. |
I just did a test today. I put in 0.82g in a glass and I put in 4ml of sulfuric acid. There was both yellow and red in the liquid. I neutralized the
liquid with bicarbonate solution (I should have poured in the solution instead of spraying! I had a small explosion But thankfully nothing got on me
and nothing was damaged, even the glass.) So as you put it, it has perchlorate with a good deal of chlorate contamination. I will need to destroy the
chlorate with HCl (and I must do very slowly because there will be a large amount of chlorate and chlorine gas is both dangerous and explosive) I
assume.
Quote: Originally posted by Alkoholvergiftung  | Couldn t you use the Aceton purification methode? Sodiumperchlorate is soluble in aceton chlorate not. If it disolve you can be sure its Perchlorate.
[Edited on 22-10-2025 by Alkoholvergiftung] |
Not yet. But I will be doing that tomorrow and post again on the results. I will be grinding up what I have into a fine powder and weigh it before
using the appropriate amount of warm acetone to see how much dissolves.
| Quote: | | I always suggest you to make KClO4 because it's less hygroscopic and it's easy to store. The solubility at room temp is less but if you heat it enough
it's pretty soluble, purification is easy and ion exchange reactions are pretty easy when KClO4 is used compared to NaClO4, advantage of NaClO4 is
it's better solubility. |
Most documentation is about sodium perchlorate though... This makes me wonder. What about barium chlorate and perchlorate? The reason why I ask is
that if I can make barium perchlorate, then using that to make ammonium perchlorate will be even easier... since if I use something like ammonium
carbonate to do an ion exchange, the resulting barium carbonate is practically insoluble in water, meaning all what will be left in solution is
ammonium perchlorate and excess ammonium carbonate, the latter is very easy to get rid of as it decomposes with even mild heating.
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ManyInterests
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Ok so I finally got to trying to dissolve some of my product... and I got something! I measured out 50g of finely powdered stuff and I used 200ml of
acetone (an excess, as sodium perchlorate is around 50g per 100ml or so of acetone) and I heated it up to boiling. Then with strong stirring I added
all the of the powder. Some of it definitely did dissolve. How much? I don't know. I am drying out the stuff that didn't dissolve so I can weigh it
out, but at least I got something.
So I started a 2nd synthesis. This time I am using 600g of sodium chloride, 4g/l persulfate, an 2000ml of water. I put the electrodes MUCH closer
(1cm) and the current is able to be much stronger. But my wires are burning out. I think I know why, but one problem is that I will need to halt the
synthesis and cut out the corroded part of the wires and bring fresh wire on the electrodes, that does bring the current back up. Clamps are also
necessary for a good connection. Electrical wire is no good as it appears to be burning due to the heat.
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woelen
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If you have red material on addition of conc. H2SO4, then you have considerable chlorate contamination. This red/orange material is highly
concentrated ClO2 in liquid (dissolved) form, which is very unstable and easily explodes (as you have noticed). From here, I cannot tell how much
perchlorate you have, but I am afraid that at best you have a few tens of percent of perchlorate, the rest being mainly chlorate (and possibly some
chloride).
The connection at the electrodes with the wires is the most vulnerable part of an electrolysis cell. You need really thick wire and you must protect
the wire from the droplets/mist, produced by the electrolysis cell, due to strong bubbling of H2. The mist is very corrosive and electrical wire with
thin strands is quickly oxidized away to a dark goo. I used Feanor Forge's electrodes for making chlorate, with his plastic covers, using screw
connections and a protective PTFE-like ring, which keeps away the corrosive mist from the connections quite well. Even with that I had issues and had
to refresh the connections after a few days of running the cell.
[Edited on 27-10-25 by woelen]
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ManyInterests
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| Quote: Originally posted by woelen | If you have red material on addition of conc. H2SO4, then you have considerable chlorate contamination. This red/orange material is highly
concentrated ClO2 in liquid (dissolved) form, which is very unstable and easily explodes (as you have noticed). From here, I cannot tell how much
perchlorate you have, but I am afraid that at best you have a few tens of percent of perchlorate, the rest being mainly chlorate (and possibly some
chloride).
The connection at the electrodes with the wires is the most vulnerable part of an electrolysis cell. You need really thick wire and you must protect
the wire from the droplets/mist, produced by the electrolysis cell, due to strong bubbling of H2. The mist is very corrosive and electrical wire with
thin strands is quickly oxidized away to a dark goo. I used Feanor Forge's electrodes for making chlorate, with his plastic covers, using screw
connections and a protective PTFE-like ring, which keeps away the corrosive mist from the connections quite well. Even with that I had issues and had
to refresh the connections after a few days of running the cell.
[Edited on 27-10-25 by woelen] |
the explosion was quite unnerving, I am glad I am OK and nothing got busted.
And seeing the contamination makes me wonder how to make best of a bad situation. Chlorates were challenge to me (and they were the first thing I did
when I got into chemistry). I got the process down as best I can with what I have, but my yields were always terrible.
I have to cut the wires on a daily basis to ensure proper connection (right now when I woke up the current was 18a, but when I cut the wires it went
up to 26.5a)
One other thing that I think I need is more run time. If you said I have a few ten percents then... well, like I said, that is indicative of me of a
terrible run, and in my next attempt I need not only more current on average, but considerable longer run time. Chemgineer said he did a similar run
(but with no persulfates and a higher concentration of chlorides) for 60 days at 10A and he has very little chlorate contamination. I kept my run for
barely 4 days. My current run that has been going on for 1.5 days so far I will try to keep going for 14 days or a little more since the amperage will
vary. So maybe 15 days total if I can, or maybe 3 weeks if possible?
He replenished his electrolyte with more chloride. I am doing it with more persulfate solution.
And Feanor Forge's setup is awesome! I legit wish I got his PbO2 setup instead of the crap that I have. In fact, maybe sometime next year I might buy
one of his setups just for the hell of it. But for now I will have to make due with what I have.
Speaking of which, you said that I mostly have chlorates in my old batch with maybe some chloride? Many synthesis state to start with chlorate and not
chloride. Perhaps I can make an electrolyte with that instead for another run?
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Alkoholvergiftung
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ManyInterests.
In old chemistry book they wrote for Perchlorate manufacture. They used Potassiumchlorate filled it in an sack and hang it in reaction fessel. It must
be Chloride free if you have more than 5% Chloride contend no Perchlorate is formed. It must be under 27C. It must be neutral or acidic . They did it
with an CO2 bubbler you can buy some diy bubbler on amazon. In alkalien conditions only at the beginning and only with high currents there are small
amounts of Perchlorate formed. the Cathode must be only 40%to 45% survace era than the Anode because if you have an current of 150mA cm2 you have max
efficency of 54% if you have an current of 190mA cm2 you have 85% (Cathode current). hope this helps
Anode was Platin and Cathode Titan because Nickle gets correded in Perchlorate cell.
[Edited on 27-10-2025 by Alkoholvergiftung]
[Edited on 27-10-2025 by Alkoholvergiftung]
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ManyInterests
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| Quote: Originally posted by Alkoholvergiftung | ManyInterests.
In old chemistry book they wrote for Perchlorate manufacture. They used Potassiumchlorate filled it in an sack and hang it in reaction fessel. It must
be Chloride free if you have more than 5% Chloride contend no Perchlorate is formed. It must be under 27C. It must be neutral or acidic . They did it
with an CO2 bubbler you can buy some diy bubbler on amazon. In alkalien conditions only at the beginning and only with high currents there are small
amounts of Perchlorate formed. the Cathode must be only 40%to 45% survace era than the Anode because if you have an current of 150mA cm2 you have max
efficency of 54% if you have an current of 190mA cm2 you have 85% (Cathode current). hope this helps
Anode was Platin and Cathode Titan because Nickle gets correded in Perchlorate cell.
[Edited on 27-10-2025 by Alkoholvergiftung]
[Edited on 27-10-2025 by Alkoholvergiftung] |
Thanks. I think I can make it work with my potassium chlorate supply. But the details are a bit scant. I am sure I can research it a bit more.
But again... for now I need to make sure my current run finishes OK. I need to cut a fuckload of wires since they are going to keep getting corroded.
I am barely 48 hours in and it is being a pain. It isn't THAT bad, but still annoying.
I think I will replenish the electrolyte with persulfate and some sodium chloride going forward. If I do a third run after this (in a few weeks! I
hope!) I will use the chlorate that resulted from the previous two runs.
Speaking of which, I would like to know... how can I separate my sodium chlorate from sodium chloride?
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ManyInterests
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I asked chatgpt (through duck.ai) about how to removed sodium chloride from chlorate. I will post it here... is it hallucinating or is it being
factual?
| Quote: | Selective Precipitation Using Magnesium Sulfate
Using magnesium sulfate (MgSO₄) to selectively precipitate sodium chloride (NaCl) from a mixture of sodium chloride and sodium chlorate can lead to
the formation of the following salts:
Resulting Salts
Sodium Chloride Precipitation:
When magnesium sulfate is added to the solution, it reacts with sodium chloride to form magnesium chloride (MgCl₂), which remains soluble.
The sodium chloride will precipitate out: MgSO4+2NaCl→MgCl2+Na2SO4(solution)
The precipitation of NaCl can also occur under certain conditions, primarily if there is sufficient concentration or if the ionic strength of
the solution changes significantly.
Sodium Chlorate in Solution:
Sodium chlorate (NaClO₃) remains in solution and does not precipitate by this process since it is more soluble than sodium chloride.
Considerations
Stoichiometry:
From 100 g of the 50:50 mixture, there are 50 g of NaCl and 50 g of NaClO₃.
The molar masses are approximately:
NaCl: 58.44 g/mol
NaClO₃: 105.44 g/mol
Moles of each:
nNaCl=58.44g/mol50g≈0.856mol
nNaClO3=105.44g/mol50g≈0.474mol
Steps to Execute the Process
Dissolve Sodium Salts:
Properly dissolve your 100 g of the sodium salts (50 g NaCl and 50 g NaClO₃) in 500 mL of water.
Add Magnesium Sulfate:
Gradually add magnesium sulfate to this solution. The amount needed will depend on the equilibrium and precipitation observed.
Precipitate Formation:
Watch for NaCl precipitation during the process. Monitor the solution clarity and turbidity.
Filtration:
After allowing time for precipitation, filter the mixture. The sodium chloride should be captured on the filter paper.
Washing and Collection:
Wash the precipitated sodium chloride to remove adhering chlorate solution.
Resulting Solution:
The remaining solution should now contain the various soluble salts (mainly the magnesium sulfate and sodium chlorate).
Summary
By adding magnesium sulfate, sodium chloride will precipitate out while sodium chlorate remains in the aqueous phase. You’ll end up with solid NaCl
and a solution containing NaClO₃ and dissolved magnesium sulfate (which may also precipitate out as MgSO₄·7H₂O upon cooling if sufficient
quantities were added).
If you would like more information on any specific steps or dosages, let me know! |
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bnull
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| Quote: | | When magnesium sulfate is added to the solution, it reacts with sodium chloride to form magnesium chloride (MgCl₂), which remains soluble. The
sodium chloride will precipitate out: |
Does it make any sense to you? If you were introducing more chloride ions by using magnesium chloride, then yeah, there's the common ion,
NaCl is the less soluble of whatever is in solution and would fall to the bottom. But adding magnesium sulfate, where magnesium chloride and chlorate
are soluble and sodium sulfate is soluble too, amounts to nothing.
No matter how you ask AI, chances are it will mess up its responses. It has facts and information, not knowledge. ChatGPT is good with translations
and finding literature. Don't trust it for the rest. For these things we have articles and books and people.
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Alkoholvergiftung
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I think they used first Potassiumchlorate because it is easyier to clean (recrystallize) than sodiumchlorate.
With lead dioxide it should be possible to go in one run but i think the elektrolysis takes much longer because i ve read when 50% of chloride is
conferted to chlorate the rate drops and it goes slower on slower so you need much more time to convert the last 5% than you needed for the first 50%.
Thats why they put an bag of chlorate inside the reaction vessle so it holds the chlorate level constant.
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woelen
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I recently made a lot of KClO3, using Feanor Forge's MMO electrodes with the plastic lid. A web page will come about that in due time. Yield is quite
good. I used plain KCl, with a little K2S2O8 added. In each run I took appr. 500 grams of KCl and a small teaspoon full of K2S2O8. When the liquid
level dropped a few cm, I added more solution of KCl and a pinch of K2S2O8, a little amount on the tip of a big screw driver.
I think I now have appr. 1000 grams of KClO3, recrystallized from distilled water to make it really pure. During the electrolysis I had to take out
solid KClO3. I also used a long narrow flower vase to assure that the electrodes did not get stuck in the solid crystal mass. That is a disadvantage
of using KCl instead of KClO3, but the great advantage is that you very conveniently can get solid KClO3 totally free from sodium ions.
Recrystallizing KClO3 from water also works like a charm. It is really pure (only the slightest opalescence with silver nitrate) after
recrystallization, but taking the crystals out of the vase and just briefly rinsing with ice cold water and pressing dry in a coffee filter with paper
tissue around it already gives quite a good product (I think better than 99%, some opalescence with silver nitrate, but no real precipitate).
My next experiment will be to make perchlorate. For that I will first use MMO to make a concentrated solution of NaClO3 (with maybe 10% chloride left)
and then I'll use that to make NaClO4 with a PbO2 anode (also from Feanor Forge). Run times must be sufficiently long.
One mole of electrons is almost 100000 Ampere-seconds of charge (actually, a little bit less, but there always will be some losses, so in practice
this 100000 Ampere-seconds is a good approximation and is convenient for hand-calculations). For one mole of KClO3 you'll need 8 to 10 mole of
electrons in a simple home-made cell. I needed well over 1 week running at 10 A, using a CC/CV power supply, limited at 10A/4.5V. Cell voltage started
at 3.3 volts or so. I switched it off, when cell voltage went well over 4.1 volts.
For th NaCl cell, I simply will run it for well over a week at 10A. There will be no visual feedback, as NaClO3 is much more soluble in water. After
that, I'll switch to PbO2 and run for another two days, maybe 3 days. Going from NaClO3 to NaClO4 only requires 2 electrons per ion. On Feanor Forge's
website I read about issues with cells, working perfectly fine up to the NaClO3 stage and then stopping at that point, giving no NaClO4. I hope I will
not be one of those people. I have the impression that making perchlorate is a matter of art, some luck, and maybe a little science 
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markx
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Perchlorates can be finnicky stuff and sometimes the synthesis halts or delays itself for no obvious reasons.....I've had my fair share of adventures
with it. But usually given enough time and keeping things from extremes (cell voltages, currents, additive package) it will complete itself at some
point and produce a nice batch of product. Even if things seem not to progress good at all starting off.
I've even managed to witness the direct formation of KClO4 on a Pt coated anode in saturated KClO3 solution. It formed as a loose layer of cristals
that flaked off and collected as a pile under the anode. Quite a sight it was, as all the sources at that time pointed towards this kind of process
being impossible
https://www.youtube.com/watch?v=zD9PlBT1laM
Exact science is a figment of imagination.......
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Alkoholvergiftung
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Sometimes is the imposible possible. Sometimes Perchlorate emerge in alkalien cells. they think if the bubbles of gas on the anode and cathode mix and
stir together it can be formed there also (as an example). But an direct conversion on pt anode is an feat. 
[Edited on 28-10-2025 by Alkoholvergiftung]
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ManyInterests
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| Quote: | Does it make any sense to you? If you were introducing more chloride ions by using magnesium chloride, then yeah, there's the common ion, NaCl is the
less soluble of whatever is in solution and would fall to the bottom. But adding magnesium sulfate, where magnesium chloride and chlorate are soluble
and sodium sulfate is soluble too, amounts to nothing.
No matter how you ask AI, chances are it will mess up its responses. It has facts and information, not knowledge. ChatGPT is good with translations
and finding literature. Don't trust it for the rest. For these things we have articles and books and people. |
Now that I think about it I feel like an idiot... yeah, this isn't going to work. I'm going to try to coax it for sources and other information...
maybe it might accidentally tell me what I need to do. Speaking of which what can I do about sodium chloride left over?
| Quote: | I recently made a lot of KClO3, using Feanor Forge's MMO electrodes with the plastic lid. A web page will come about that in due time. Yield is quite
good. I used plain KCl, with a little K2S2O8 added. In each run I took appr. 500 grams of KCl and a small teaspoon full of K2S2O8. When the liquid
level dropped a few cm, I added more solution of KCl and a pinch of K2S2O8, a little amount on the tip of a big screw driver.
I think I now have appr. 1000 grams of KClO3, recrystallized from distilled water to make it really pure. During the electrolysis I had to take out
solid KClO3. I also used a long narrow flower vase to assure that the electrodes did not get stuck in the solid crystal mass. That is a disadvantage
of using KCl instead of KClO3, but the great advantage is that you very conveniently can get solid KClO3 totally free from sodium ions.
Recrystallizing KClO3 from water also works like a charm. It is really pure (only the slightest opalescence with silver nitrate) after
recrystallization, but taking the crystals out of the vase and just briefly rinsing with ice cold water and pressing dry in a coffee filter with paper
tissue around it already gives quite a good product (I think better than 99%, some opalescence with silver nitrate, but no real precipitate).
My next experiment will be to make perchlorate. For that I will first use MMO to make a concentrated solution of NaClO3 (with maybe 10% chloride left)
and then I'll use that to make NaClO4 with a PbO2 anode (also from Feanor Forge). Run times must be sufficiently long.
One mole of electrons is almost 100000 Ampere-seconds of charge (actually, a little bit less, but there always will be some losses, so in practice
this 100000 Ampere-seconds is a good approximation and is convenient for hand-calculations). For one mole of KClO3 you'll need 8 to 10 mole of
electrons in a simple home-made cell. I needed well over 1 week running at 10 A, using a CC/CV power supply, limited at 10A/4.5V. Cell voltage started
at 3.3 volts or so. I switched it off, when cell voltage went well over 4.1 volts.
For th NaCl cell, I simply will run it for well over a week at 10A. There will be no visual feedback, as NaClO3 is much more soluble in water. After
that, I'll switch to PbO2 and run for another two days, maybe 3 days. Going from NaClO3 to NaClO4 only requires 2 electrons per ion. On Feanor Forge's
website I read about issues with cells, working perfectly fine up to the NaClO3 stage and then stopping at that point, giving no NaClO4. I hope I will
not be one of those people. I have the impression that making perchlorate is a matter of art, some luck, and maybe a little science |
I might as well make more sodium chlorate. I mean the previous run that I can reuse them, after all, there is probably plenty of chlorate in there to
be turned into perchlorate.
Right now, I am going to see how long I can keep it going. I am not sure if I can accomplish my intended goal of 3 weeks, but I can definitely do it
for a week and a day at least. I will still do my best to make it go 2 weeks. If a longer run time will make more perchlorate.
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bnull
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| Quote: | | Speaking of which what can I do about sodium chloride left over? |
I was preparing a perchlorate (or was it chlorate) cell the other day but didn't have a power supply that would work with the electrodes I was going
to use. I'll look into it and see what I can find.
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Alkoholvergiftung
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Now i found the artikel its in german and from the Chedde Company. They write Perchlorate form at ph10 too.
Attachment: Perchlorate5_1.pdf (314kB)
This file has been downloaded 115 times
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ManyInterests
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Thank you! I will use the miracle of translation software to make it English and see what I can learn! Also makes me wish I spent a little more time
learning German!
| Quote: Originally posted by bnull | | Quote: | | Speaking of which what can I do about sodium chloride left over? |
I was preparing a perchlorate (or was it chlorate) cell the other day but didn't have a power supply that would work with the electrodes I was going
to use. I'll look into it and see what I can find. |
You made me forget... I think if worst comes to comes to worst, I will pull out my IR-TI MMO (using a stainless steel ruler for a cathode) and make a
setup to allow for conversion of all chloride into chlorate, and then switch to the PbO2 setup. I am starting to think that the whole starting from
chloride thing is a giant mistake. I am assuming that if I have a mixture of chloride, chlorate, and perchlorate, the perchlorate and chlorate will be
unaffected by that.
Also I seriously am considering shelling out another 200$ in a few months on Feanor Forge's setup. But like I said, I want to run this one to its
logical course before buying anything.
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markx
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| Quote: Originally posted by Alkoholvergiftung | Sometimes is the imposible possible. Sometimes Perchlorate emerge in alkalien cells. they think if the bubbles of gas on the anode and cathode mix and
stir together it can be formed there also (as an example). But an direct conversion on pt anode is an feat.
[Edited on 28-10-2025 by Alkoholvergiftung] |
It quite consistently forms in alkaline cells according to my experience....I've done numerous direct full conversions of Cl- to ClO4- in single runs
with Pt coated Ti anode and Ti cathodes. No additives or pH corrections at any stage, just let it tick along at a minimum cell voltage which still
enables reasonable current flow (less than 5V), top up with water as required (or chlorate solution) and it usually works out just fine. The solution
after the ClO3- stage is quite alkaline, but it seems to pose no obstacle for further ClO4- formation. Nor does the residual Cl- content, since it
reaches an equilibrium concentration parallelly forming during perchlorate synthesis stage anyways (even if one was to start out with pure chlorate
solution). I've had no sudden passivation or other destructive events happening at the chlorate formation stage end. It just passes gradually over to
perchlorate synthesis and keeps on going. But as the ClO3- is depleted and the run nears the full conversion limit, the passivation can set in quite
suddenly and the anode gives up it's ghost. The same is true if one pushes the cell voltage past 5V. It steeply raises the anode polarisation and
intensifies competitive reactions (passivation or degradation due to excessive O2 formation e.g.).
Patience and time are your allies in this game....don't fiddle with the system nor push the cell to the limits and just give it time to do it's thing.
A month of constant running was about my realistic and repeatable pace for a full conversion of a 3l cell starting from chloride. Apart from adding
electrolyte to top off the lost volume I basically ran it unsupervised and it worked like a charm.
Just accept the fact that any anode beside a solid chunk of Pt is pretty much expendable when a near full conversion of ClO4- is required. One can
halt sooner and use selective precipitation and further purification to harvest the perchlorate and push a bit more life out of the anode, but
eventually it shall passivate or disintegrate (in a few runs). The conditions are way harsher than during chlorate formation which can be run
seemingly indefinitely with a MMO and some common sense.
Exact science is a figment of imagination.......
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Alkoholvergiftung
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oh than i always did the fals voltage for perchlorates. literature wrote 5,5V-6,5V
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