making potassium (per) chlorate

[Arthur]

There has been a DIY method of making lead dioxide electrodes, but usually there is the problem of the residual mess to clear up. Careful searching of ebay and other sales sites will often source useful items, likely from overseas.

 

Alternatively a fine platinum foil -very thin say 5 - 15 thousandths of an inch - could be spot welded to a stem. Platinum requires very low ripple power supply.

[WSM]

I appreciate the response. Arthur also pointed out the solubility issue as well. I never even considered it.

On a different topic (and if you addressed this already, I apologize) I've only read Parts 1-5 or 6 of your overall thread so far: is the lead dioxide or lead something anode a viable homemade option? I vaguely recall reading or watching a YouTube video about making your own anode with some lead product, but can't recall feasibility or if it was even successful. It's the platinum / rare metal blend anode that's so expensive, which I've read will need to be replaced periodically, that has really prevented me from trying this at any scale.

I'm still following along with interest though!

Charles

 

 

The lead (Pb) type anode material is the beta form (hard crystalline) and not the alpha form (spongy, soft) which is typically found in lead/acid car batteries. The beta form lead dioxide is more challenging to produce without the proper equipment, but possible.

 

I've decided that if I ever attempt to make my own LD anodes, my first choice would be to make a GSLD (graphite substrate lead dioxide) anode which shows promise of being able to produce sodium perchlorate directly from sodium chloride, with the proper setup and catalyst.

 

Swede did make an LD anode on an MMO substrate, and the only bond failures appeared where the MMO mesh was cut, exposing the titanium substrate. In practice, the LD anode (with CP titanium cathodes) he made successfully created perchlorates. It was a small, proof-of-concept cell.

 

To date, the only LD anodes I've tried were imported from China and sold by someone on eBay.

 

WSM

[kingkama]

 

 

The lead (Pb) type anode material is the beta form (hard crystalline) and not the alpha form (spongy, soft) which is typically found in lead/acid car batteries. The beta form lead dioxide is more challenging to produce without the proper equipment, but possible.

 

I've decided that if I ever attempt to make my own LD anodes, my first choice would be to make a GSLD (graphite substrate lead dioxide) anode which shows promise of being able to produce sodium perchlorate directly from sodium chloride, with the proper setup and catalyst.

 

Swede did make an LD anode on an MMO substrate, and the only bond failures appeared where the MMO mesh was cut, exposing the titanium substrate. In practice, the LD anode (with CP titanium cathodes) he made successfully created perchlorates. It was a small, proof-of-concept cell.

 

To date, the only LD anodes I've tried were imported from China and sold by someone on eBay.

 

WSM

maybe I was lucky, but using a platinum anode that unfortunately I destroyed due to carelessness, I managed to obtain a lead oxide plated anode. I tried using the Graphite as a substrate, but instead of being simpler the plating is actually complicated and brittle, even when done with the use of an ultrasonic bath and by rotating the electrode.I think probably the trick is to use a saturated bath and add some lead so that it buffers the nitric acid that builds up during plating while also keeping the bath saturated It is also necessary to add copper nitrate to reset the cathodic reduction. Mandatory is to use an anode coated with MMO or platinum, as the lead oxide will oxidize the surface of the plated metal.Probably the result will not be like those sold which, by the way, are not plated but covered with a paste which is then cooked in the oven. The electrode proved to be functional and resistant even to currents much higher than those allowed by its dimensions. Surely being able and having funds it is better to buy Industrial electrodes and use them below the permitted currents to prolong the life. Edited January 31, 2023 by kingkama

[cmjlab]

"Surely being able and having funds it is better to buy Industrial electrodes and use them below the permitted currents to prolong the life.

Edited by kingkama, Today, 03:33 PM."

 

With the price of a platinum anode that will actually last any length of time (unlike the cheap jewelry ones on Amazon), it would kill me to use that as the substrate for a lead dioxide anode that MAY work, but likely WON'T! So I definitely agree with your last statement it may be cheaper, or at least more cost effective to purchase a quality anode.

 

I apologize WSM, not trying to detail your thread. I was just wondering if there was any benefit to the lead dioxide anode, as I assume it would be cheaper to an equivalent MMO or Platinum anode.

[WSM]

I apologize WSM, not trying to detail your thread. I was just wondering if there was any benefit to the lead dioxide anode, as I assume it would be cheaper to an equivalent MMO or Platinum anode.

 

 

If available, a good quality lead dioxide anode is MUCH cheaper than a high quality platinum anode. Lightly loaded, they appear to hold up in a perchlorate cell without undue wear. I believe a lot of perchlorate can be produced with one.

 

WSM

[Arthur]

Platinum was the go-to inert electrode for years but it is expensive. Lead Dioxide electrodes work perfectly usually they pop up in online sales places usually when someone has bought ten from China and wants to move nine of them.

[kingkama]

"Surely being able and having funds it is better to buy Industrial electrodes and use them below the permitted currents to prolong the life.

Edited by kingkama, Today, 03:33 PM."

 

With the price of a platinum anode that will actually last any length of time (unlike the cheap jewelry ones on Amazon), it would kill me to use that as the substrate for a lead dioxide anode that MAY work, but likely WON'T! So I definitely agree with your last statement it may be cheaper, or at least more cost effective to purchase a quality anode.

 

I apologize WSM, not trying to detail your thread. I was just wondering if there was any benefit to the lead dioxide anode, as I assume it would be cheaper to an equivalent MMO or Platinum anode.

Lead dioxide was used to protect the platinum anodes, so using it as a substrate for the lead is the best that can be done to protect it. Because you have doubts about the functioning, I have often noticed that in the forums there is a tendency to discourage and always question those who try new paths, I am sure It will not convince you but the anode plated by me works very well, Even if the plating were to give up, in less than an hour it regenerates easily and with a negligible cost. The PbO2 anodes are superior to the platinum ones in terms of resistance and performance, with them it is possible to reach 5% chlorate without damage Instead, as I discovered at my expense, platinum easily receives , the electrical yield especially using persulphates as additives is higher than any other electrode. I reiterate that to save time and effort, it is better to buy industrial anodes, but, here, I don't think there are any professional users interested in large quantities Or for which the time dedicated to experimentation is time wasted or taken away from pyrotechnic work, because it is obvious that at that point it is better to buy ready-to-use kclo4. Edited February 1, 2023 by kingkama

[cmjlab]

.... Because you have doubts about the functioning, I have often noticed that in the forums there is a tendency to discourage and always question those who try new paths, I am sure It will not convince you but the anode plated by me works very well....

I'm not sure why you believe I have doubts about your experience or success - I don't, and as far as I know have no reason to doubt you. You haven't said anything I found or could prove wrong.

 

I DO have doubts that I could figure it out, and doubts I'd be willing to try plating with lead dioxide at risk of ruining an expensive anode,and the mess I'd likely be left with because of my lack of expertise in that area.

 

We both definitely agree that it's cheaper to buy, but that doesn't mean I wouldn't like to try a cell for a purity comparison.

[Powderman]

I find this beautiful, and it is related to this thread :-)

 

https://youtube.com/shorts/ReaQWrSZi0o

Edited February 2, 2023 by Powderman

[THEONE]

You can check this channel out for homemade LD anode, this channel is treasure

 

https://www.youtube.com/@CatboyChemicalSociety/videos

[Powderman]

I would like to try making chlorate (and later perchlorate), I even have MMO and Ti electrodes, but I would like to try it first in small scale to learn how to successfuly operate it. But I failed to find small electrodes for low volume few amps cell. Does anybody know where to find it?

[Arthur]

Titanium seems to crop up on ebay here.

 

Just be cautious because small cells do not run like big cells! The process is temperature dependent and big cells hold a steady temperature while small cells do not, the heating comes from the eletrode supply in a big cell a small cell may need heating.

Also the reaction consumes water, in a small cell you need to closely monitor the level.

Edited February 22, 2023 by Arthur

[Powderman]

Yes I am aware that thermal management would be different but I think it can be sorted out with some heating/insulating of the cell... Most probably I will utilize arduino based control to monitor and regulate.

[WSM]

I would like to try making chlorate (and later perchlorate), I even have MMO and Ti electrodes, but I would like to try it first in small scale to learn how to successfuly operate it. But I failed to find small electrodes for low volume few amps cell. Does anybody know where to find it?

 

 

It may be best to just jump in with the electrodes you have. My first successful cell was a glass, one gallon pickle jar and it made lots of potassium chlorate before it was retired. I believe a 5 gallon (+-19 liter) HDPE bucket cell can conservatively make 200lbs (~100Kg) of KClO3 a year with semi-constant running (with a more optimal setup, even more!).

 

I find that electrolyzing potassium chloride brine (electrolyte) to be very straight forward, and a very forgiving way to start. Be sure to use distilled or deionized water, to avoid adding unwanted ions to your electrolyte.

 

Read through the first few "Homegrown Oxidizer" blog posts for details on methods that work, to set up your cell. If you have problems or run into difficulties, ask here for suggestions or guidance. Many here have some level of experience and can offer ideas which can help.

 

Let us know how it goes.

 

WSM

[WSM]

Titanium seems to crop up on ebay here.

Just be cautious because small cells do not run like big cells! The process is temperature dependent and big cells hold a steady temperature while small cells do not, the heating comes from the eletrode supply in a big cell a small cell may need heating.

Also the reaction consumes water, in a small cell you need to closely monitor the level.

 

 

Remember, there is titanium and then there is titanium. The best grades of titanium to use for electrodes are listed as CP, or Commercially Pure which have very low levels of alloying metals in them which could add unwanted ions in a chlorate or perchlorate cell (and contaminate your product).

 

When searching for titanium to use for cathodes, specify CP titanium, and avoid alloys with added metals for physical strength. We need chemical strength, not physical strength.

 

WSM

[WSM]

Yes I am aware that thermal management would be different but I think it can be sorted out with some heating/insulating of the cell... Most probably I will utilize arduino based control to monitor and regulate.

 

 

If you use the electrodes you have in a 2-6 liter cell, I expect it will naturally run warm enough to not need temperature controls of any kind. Electrical inefficiencies usually manifest as heat. It's not all bad, the heat improves the performance of the cell (but not excessive heat, which indicated a serious problem with the setup).

 

Do remember the chlorate cell runs alkaline and if no pH control is used, the current efficiency will typically be ~45% at best. It still works and can work well, but maintaining the pH as close as possible to the ideal of 6.8 (very slightly acid) will improve efficiency greatly, and yield more product for the current applied.

 

The pH control is usually achieved by periodic small additions of dilute hydrochloric acid. Ask questions for details of how others here have done this, but don't hesitate to run the cell without pH control, because it works and a lot of material can be produced. If you opt for pH control, avoid too much acid addition or your cell may pump out chlorine gas , especially if your pH nears 6.0 or below!

 

WSM

 

PS- The first run of your chlorate cell will yield less product than subsequent runs with recharged electrolyte. This is because a large portion of the current is used in the first run of the cell to make precursor ions (hypochlorite, chlorite and chlorate) which are already there in the "used" electrolyte which has been recharged with more potassium chloride brine and then run again. Runs after the first one will produce more product in less time, due to those precursor ions already being there!

Edited February 26, 2023 by WSM

[Powderman]

I found my electrodes I bought in past, 2" x 6" with flat handles. I am still thinking about the proper way how to install them to the lid and prevent salt creeping. I have THF so I can dissolve PVC easily and use it like laquer, glue or sealant. I am not aware someone used it like this so it might be a way... Maybe I could use it as a barrier to protect another sealant/material (epoxide, silicone...)

So would be 4 litre glass jar good fit for KClO3 test run? What type of lid do you suggest? Is glass vessel safe with persulfate additive - would it prevent cell going too alkaline to attack glass? Or is adding HCl the only way to prevent it?

Does it help to shortly boil small sample of brine in test tube before testing with PH indicator paper (destroying hypochlorite bleaching it)?

[Arthur]

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.

[Powderman]

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.

Yes, why dilute HCl with water when one can dilute with fresh salt brine. If I have to add HCl this would be the way. But I was hoping to find out if HCl is needed when persulfate is used.

[cmjlab]

Isn't persulfate closer to hydrogen peroxide, than it is an acid?

[Arthur]

Persulphate is a recognised and good additive to moderate the pH of this reaction. Persulphate is also available in some places where conc acids are not.

[Arthur]

Persulphate is also used as part of a laundry detergent mix...

[cmjlab]

Hydrogen peroxide is used as a detergent and a whitener...?

The first response was helpful, the second not so much. Thanks though.

[cmjlab]

Not to beat a dead horse and dive down unimportant rabbit holes, I see that persulfate is a strong oxidizer, similar to hydrogen peroxide, used for many things such as polymerization reactant for styrene (main use - Wikipedia), and pages and pages of scientific documents and studies on it's use as a ground water treatment additive due to its affinity and attraction to Iron and Manganese, and it's ability to last longer in water with trace amounts of those elements. I see it's used in many other smaller applications, but none of which include controlling / balancing alkaline conditions.

 

I don't claim to know everything, I simply had a curiosity of why one would use persulfate (a strong oxidizer, similar to hydrogen peroxide), and if one could use it (which I'm not in a position to say someone could not), then could you use normal hydrogen peroxide (3%) to control alkalinity in a chlorate cell.

 

Then a final curiosity, does it introduce sodium contamination back into the chlorate cell, which based on my understanding of the above conversation, has avoided any sodium salts all the way till you add sodium persulfate, a derivative of sodium bisulfate.

 

That's the only reason I asked about it's comparison to peroxide. Again, I apologize to the OP for my rant.

Edited February 28, 2023 by cmjlab

[CountZero]

Use potassiumpersulfate to avoid sodium contamination. My understanding is that it is added to improve effiency,the mechanism behind this I dont know.