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making potassium (per) chlorate


gods knight

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I took a look at solubility of Na and K persulfate and it is easy to make K persulfate from Na persulfate (which seems to be more available) the same way K chlorate is made from Na chlorate. I have found it in an e-shop as etching solution for printed circuits. But using Na persulfate in potassium chlorate cell is no big deal - more Na is probably contained in technical grade KCl. For use in blue stars the chlorate should be at least one or two times recrystallized.
H2O2 at most makes some bubbles and it is gone... For additive to be useful it has to be persistent in the cell and able to aid the wanted reactions or block unwanted ones.

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Sometimes, in the arcane world of electochemistry odd things happen. One of the soluble brighteners to make metals plate directly to a shiny bright finish was simply sugar. There was no logical reason why, but it did work so people used it. Of course the chemical manufacturers had to make something better or they would lose business.

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Thanks Powderman / Arthur - that is certainly helpful for me to understand better. I will gladly admit that from the pages and pages I've read on persulfate, it's biggest benefit is it's unique ability to not only persist longer than H202 can, but it also seems to thrive or "activate" in the presence of Iron (III) Oxide and/or Manganese effectively enhancing it's beneficial effects. But I imagine you will be using distilled water, without the Fe/Mn. Edited by cmjlab
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Let us know how it works. It's certainly widely available near me as a spa water treatment chemical.
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  • 3 months later...

After NaClO4+KCl double displacement reaction when recycling old electrolyte the perchlorate contamination it didn't cause any problems for anyone with MMO anodes? In perchlorate cells chlorides highly erode perchlorate anodes too. Sodium chloride contaminated with perchlorate is obtained. When I tried to recycle the solution, I found that it was too erosive. Production Of Potassium perchlorate * By CLIFFORD A. H A M P E L AND P. W . LEPPLA recycling the solution back to the NaClO3 process. But plenty of documentation says that even platinum is severely damaged by this. I currently trying use hot KClO3+NaClO4 solutions and hot filtering see patent CN102807192A Potassium perchlorate production technology with zero wastewater discharge and products thereof. I can make it in half the time the KClO3 than the NaClO3 (1 week vs 2), and NaClO3 -> NaClO4 conversion are faster. But I see that at home everyone using the KCl+NaClO4 reaction. This didn't cause any problems for anyone? MMO anode shows signs of damage after several uses or not? This is a problem in industry, in amateur groups there are not too much feedbacks.

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  • 1 month later...

After NaClO4+KCl double displacement reaction when recycling old electrolyte the perchlorate contamination it didn't cause any problems for anyone with MMO anodes? In perchlorate cells chlorides highly erode perchlorate anodes too. Sodium chloride contaminated with perchlorate is obtained. When I tried to recycle the solution, I found that it was too erosive. Production Of Potassium perchlorate * By CLIFFORD A. H A M P E L AND P. W . LEPPLA recycling the solution back to the NaClO3 process. But plenty of documentation says that even platinum is severely damaged by this. I currently trying use hot KClO3+NaClO4 solutions and hot filtering see patent CN102807192A Potassium perchlorate production technology with zero wastewater discharge and products thereof. I can make it in half the time the KClO3 than the NaClO3 (1 week vs 2), and NaClO3 -> NaClO4 conversion are faster. But I see that at home everyone using the KCl+NaClO4 reaction. This didn't cause any problems for anyone? MMO anode shows signs of damage after several uses or not? This is a problem in industry, in amateur groups there are not too much feedbacks.

 

 

I haven't yet tried recycling the electrolyte from the sodium perchlorate/potassium chloride exchange, so I have no information regarding MMO harm/damage problems.

 

It has been reported HIGH levels of chlorides in a perchlorate cell using platinum anodes, damages the platinum, and should be avoided. Considering the cost of platinum metal, it seems to be sound advice.

 

In my experience, making sodium perchlorate from sodium chlorate worked quite well using either platinized titanium or lead dioxide on titanium anodes with titanium cathodes (I did two cell runs, one with each type of anode, to compare them). My research prompted me to run the small experimental cells with low current densities (compared to reported commercial voltage and current levels) due to statements from others of damage to Chinese made LD anodes. I assumed they were run with higher voltages and currents, which caused them to be compromised (falling apart during the attempted operation).

 

I ran my small cells at roughly 4-4.5 Vdc and at a current density between 1.0 and 2.0 Amps per square centimeter. The cell volumes were about 3 liters each and had a distinct ozone odor at the vent tube, but the level of ozone production was low enough not to be an issue (I describe the odor as a "fresh air" smell and not overpowering). No chlorine odor was detected at all.

 

I had only 8 pounds(<4 Kilos) of commercial sodium chlorate for the perchlorate cell electrolyte, and no source to replace it when it was used up (which motivated me to research sodium chlorate production afterward).

 

I ran into issues with my research and have made little progress since 2016, but I haven't given up. I've been busy with other projects and fully intend to continue my research when things slow down. My notes here will continue as I make further progress...

 

WSM B)

Edited by WSM
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Professionally a chlorate cell is pH controlled by topping up with a brine/hydrochloric acid mixture. As the cell works brine is consumed and acid is consumed.

 

 

As to the use of persulfates, I have no experience. I am more prone to using things that don't add anything not already in the chlorate or perchlorate cells. I prefer to avoid contaminants for a purer end product(s).

 

Sulfuric acid or sulfates aren't things I'd want in my products or solutions.

 

WSM B)

 

Edit: When purifying sodium perchlorate (removal of residual chlorate) before exchanging with potassium chloride solution (to make the end product, potassium perchlorate), I've used a solution of sodium metabisulfite to break down chlorates to chloride (leaving the sodium perchlorate solution chlorate-free). This process DOES add sulfate to the solution.

 

Before being able to reuse the "depleted" electrolyte, I reasoned that removal of sulfides or sulfuric acid was possible by treating that electrolyte with calcium chloride solution which would precipitate low-solubility calcium sulfate, which then could be removed with a vacuum filtration setup before recharging the brine with more sodium chloride.

 

One would want to be sure to remove any residual calcium from the electrolyte before running the sodium chlorate cell with the recovered electrolyte (I've been told that calcium chlorate would be a dangerous contaminant and should be avoided).

 

The economy of recovering spent electrolyte on such a small scale usually isn't worth the effort, so it is safely disposed of instead.

Edited by WSM
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  • 1 month later...

As to the use of persulfates, I have no experience. I am more prone to using things that don't add anything not already in the chlorate or perchlorate cells. I prefer to avoid contaminants for a purer end product(s).

Sulfuric acid or sulfates aren't things I'd want in my products or solutions.

WSM B)

 

Edit: When purifying sodium perchlorate (removal of residual chlorate) before exchanging with potassium chloride solution (to make the end product, potassium perchlorate), I've used a solution of sodium metabisulfite to break down chlorates to chloride (leaving the sodium perchlorate solution chlorate-free). This process DOES add sulfate to the solution.

Before being able to reuse the "depleted" electrolyte, I reasoned that removal of sulfates or sulfuric acid was possible by treating that electrolyte with calcium chloride solution which would precipitate low-solubility calcium sulfate, which then could be removed with a vacuum filtration setup before recharging the brine with more sodium chloride.

One would want to be sure to remove any residual calcium from the electrolyte before running the sodium chlorate cell with the recovered electrolyte (I've been told that calcium chlorate would be a dangerous contaminant and should be avoided).

The economy of recovering spent electrolyte on such a small scale usually isn't worth the effort, so it is safely disposed of instead.

 

Edit: See correction in color above.

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  • 1 month later...

I ran into issues with my research and have made little progress since 2016, but I haven't given up. I've been busy with other projects and fully intend to continue my research when things slow down. My notes here will continue as I make further progress...

WSM B)

 

 

Well, as life continues and gets more complicated, my energies are focused on improving my home and paying it off, preparatory to retirement, so my electrochemical research has been on hiatus. I absolutely plan to continue my research and writing, going forward.

 

One of my current projects is completing an off-grid solar project (I'm very close) for, among other things, a free (after infrastructure expenses and effort) power source for the next 15+ years. I can see making chlor-alkali oxidizers for little more than the cost of salt and effort, once everything is in place.

 

WSM B)

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One of my current projects is completing an off-grid solar project (I'm very close) for, among other things, a free (after infrastructure expenses and effort) power source for the next 15+ years. I can see making chlor-alkali oxidizers for little more than the cost of salt and effort, once everything is in place.

WSM B)

 

 

My solar project is an off-grid system ("free" electricity) which will afford me the ability to run a chlorate and perchlorate system for low cost. It can also provide a continual source of pure distilled/de-ionized water, by use of a higher-end dehumidifier which automatically dumps pure condensate periodically into a float-switch-controlled reservoir (to prevent an overflow). I can also use pumps to move the water to wherever it's needed. Lot's of potential!

 

I see exciting times ahead :D! More later...

 

WSM B)

Edited by WSM
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  • 4 months later...

After running my solar experiment successfully for a short time, I was compelled by a City Inspector, to remove the panels because I failed to obtain a permit for it. I wasn't aware a permit was required for an off-grid installation until after I set it up.

I opted to remove the offending panels rather than invite official snooping into my private pursuits.

If I am able to install an off-grid PV system on my home, I will follow that course and feed my workshop from the power produced thereby. We shall see...

WSM B)

Edited by WSM
clarity
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