The Bucket Cell - Start to Finish

[Arthur]

Much as the electro cell poses interesting technical problems, having solved these, the rest of the process has some interesting issues, not least of which is the production rate. For my purposes a 3 litre cell is fine if run for threeish weeks to make several kilos. If you have need for more then you really need to plan for lots of cells and lots of work to do, and masses of cleaning up to prevent salt splash from the cell and drips from everywhere. The aerial mist gets everywhere (I've just looked inside a power supply ). Any spilled liquid is a powerful herbicide.

[WSM]

Much as the electro cell poses interesting technical problems, having solved these, the rest of the process has some interesting issues, not least of which is the production rate. For my purposes a 3 litre cell is fine if run for threeish weeks to make several kilos. If you have need for more then you really need to plan for lots of cells and lots of work to do, and masses of cleaning up to prevent salt splash from the cell and drips from everywhere. The aerial mist gets everywhere (I've just looked inside a power supply ). Any spilled liquid is a powerful herbicide.

 

 

Different people have different needs. I find that the more materials I have on hand, the more uses for them become apparent to me. If nothing else, they can be used for trading stock with others who have excess things that I'm running short on (I'd gladly trade some surplus KClO₃ for some Ba(NO₃)₂ my friend has an abundance of).

 

It depends on where you live and what you're able to do there. I've got a fair collection of organic dyes and an interest in expanding my knowledge of color smoke devices, which comes in handy with aerial tracking for amateur rocketry . About half of the composition's makeup is potassium chlorate.

 

In fireworks, some of the best aerial stars use KClO₃ for excellent colors with large flame envelopes. Of course, one must practice the extra precautions necessary when working with chlorates, and avoid specific combinations which present undue hazards.

 

WSM

Edited January 9, 2020 by WSM

[Arthur]

I have a 3litre cell that sits in a 10litre bucket and works fine, a bigger cell needs a bigger bucket to sit in to catch any drips, leaks etc.

 

If you think this is too small for you then please look into how you will pump the solutions around as lifting a 25litre drum could be an issue and spilling it certainly is an issue.

[WSM]

I have a 3litre cell that sits in a 10litre bucket and works fine, a bigger cell needs a bigger bucket to sit in to catch any drips, leaks etc.

If you think this is too small for you then please look into how you will pump the solutions around as lifting a 25litre drum could be an issue and spilling it certainly is an issue.

 

 

As Swede pointed out, a containment for the 5 gallon (~19 liter) bucket cell is possible by using a disposable (thin black polymer, likely PE or PP) concrete mixing pan available from many big-box home centers across the US. Place the bucket in the tray (~ 7 to 9 gallons capacity) and if the bucket ruptures, the contents are kept from getting away.

 

As for mists and vapors, there are systems and methods available to mediate them and keep your setup from being a problem. It does take some thought and effort, but it's worth the trouble, if you run your cell for an extended period or especially if you choose to run it indoors.

 

WSM

Edited January 12, 2020 by WSM

[WSM]

The aerial mist gets everywhere (I've just looked inside a power supply ).

 

 

I've mostly run my electrochemical experiments outdoors (I live in a temperate area), but I see the need to protect the electronics from corrosives, and the elements in my case, while still allowing for proper ventilation.

 

My last setup used an old, beat up wooden workbench, someone in the neighborhood hung a "FREE" sign on. My Son and I grabbed it for one of his projects, but he quickly lost interest in using it, so it became mine to use . I moved it to a lonely spot in the back yard, covered the bench top with a woven blue plastic tarp and set up my sodium chlorate experiment on the top of it. I put the power supply on a shelf under the experiment, where the bench top and plastic would afford some protection for it. The electric power to the cell was carried by welding cables, long enough to offer a drip loop to avoid carrying rain water or electrolyte spills down to the electronics. This has worked very well, so far.

 

Another option is to enclose everything in a small hutch or mini-shed, with separate sections for the electronics and the cell, plus have good ventilation; and then run an electric buss bar to the cell experiments, maintaining a proper separation between both of those sections.

 

There are many ways to solve these issues and the creative designer is only limited by their individual imagination and budget.

 

WSM

Edited January 12, 2020 by WSM

[WSM]

I need to move my experimenters work bench to another location; this time with a better foundation (cinder paver stones over plastic sheeting, leveled with sand) and closer proximity to a power source, my garden workshop. I'm considering adding a roof, overhanging the whole workbench, as well as semi-enclosing it. We'll see...

 

Also, this will be physically further from my vegetable garden boxes, which also need an upgrade (the 2" x 10" boards framing it are failing and a better setup is called for)! Fortunately, I haven't spilled any electrolyte anywhere I'd like plant life to be and thrive . A little (course KClO₃ crystal) was used to kill off some weeds that blocked the access port to the crawl space under my house, but the effect only lasted two years (longer would have been better in this case).

 

I'm also working on a cistern and water purification (and storage) system. This will also serve as an emergency water source in case a natural disaster strikes (we're drought and earthquake prone here). An onsite, pure (DI) water source will also be useful for my electrochemical research.

 

So many projects, yet so little time... It would be enviable to have both enough time and money to pursue all these goals. One day, perhaps...

 

WSM

Edited January 12, 2020 by WSM

[WSM]

As for making my bucket cell adapter (or, as Swede called it, BCA), I've got a large piece of 3/4" (19 mm) thick, grey PVC plate that I can cut pieces from to use. I like the idea of using a planer or router to clean up the edges of the BCA blank, plus chamfer the top edges and corners with the router for safety in handling as well as giving the whole thing a cleaner look.

 

After it's cleaned up and before mounting it to the lid of the cell, it can be drilled and tapped for electrode fittings and other equipment, and then be put into service.

 

I look forward to trying it for myself before too long. I'll post photos when I get started .

 

WSM

[WSM]

My high temperature sodium chlorate cell has taken a big step forward. Rather than PVC or even PVDF for the lid; a fortunate find on eBay has scored a one inch thick piece of PTFE plate, big enough to make a nice lid for my wide mouth 5 liter reaction flask!

 

No more compatibility concerns!!!

 

WSM

[robbo]

I have no intention of making chlorate or perchlorate, but I find these threads fascinating and really informative. You guys have collectively done the community a great service.

If I should, in a moment of insanity, decide to travel this road I will journey the path of giants. Thanks for a great read.

[WSM]

I have no intention of making chlorate or perchlorate, but I find these threads fascinating and really informative. You guys have collectively done the community a great service.

If I should, in a moment of insanity, decide to travel this road I will journey the path of giants. Thanks for a great read.

 

 

Thanks for the kind words.

 

If you DO decide to get started on the path, don't hesitate to ask questions if you get stuck on any part of it. Several folks will usually step up with all sorts of suggestions. Someone will probably mention just what you need to overcome an obstacle you're facing.

 

I've found that the best training is the experience of making a small, simple cell and running it. A lot more is learned by doing this, and then reading (studying) everything you can find on the subject, which will add to your experience.

 

Try it and see if I'm right !

 

WSM

Edited April 5, 2020 by WSM

[WSM]

Thanks for the kind words.

If you DO decide to get started on the path, don't hesitate to ask questions if you get stuck on any part of it. Several folks will usually step up with all sorts of suggestions. Someone will probably mention just what you need to overcome an obstacle you're facing.

I've found that the best training is the experience of making a small, simple cell and running it. A lot more is learned by doing this, and then reading (studying) everything you can find on the subject, which will add to your experience.

Try it and see if I'm right !

WSM

 

 

Over a decade ago, my first successful KClO₃ cell was fabricated from a 1 gallon (3.785 liter) pickle jar with a 4" (~100 mm) PVC cap for a lid. I drilled holes for the electrodes and vent tube.

 

Filled with roughly 3 liters of KCl electrolyte and run from a 5 Vdc, 10 Amp power supply, it produced several batches of potassium chlorate using a CP titanium tube for a cathode and an MMO on CP titanium, solid round rod anode, acquired from a cathodic protection company in my area. This is the cell mentioned in my blog, Homegrown Oxidizers, part 1. The description in the blog is accurate. It was inefficient, un-metered and NOT optimized by any means, but it was successful!

 

The electrolyte was made by dissolving water softener grade potassium chloride pellets in distilled water. While the cell ran, after a few days, potassium chlorate crystals (being less soluble than the electrolyte) would form and float down in the cell like snow flakes, and settle on the bottom of the cell.

 

For me it was the best way to start the oxidizer production process because, luckily it's so forgiving that it's nearly fool-proof.

 

WSM

Edited April 12, 2020 by WSM

[WSM]

I'm halfway through rebuilding the electrodes for a friend's bucket cell. In the first version, the leads were too small and heating was a serious problem.

 

I've since remade the leads and upgraded from 6 mm OD titanium tubing to 3/8" (~9.5 mm) OD tubing, and plan to fill the space inside with 1/4" (6.35 mm) OD solid round copper rod. I find the solid copper conducts electricity so much better than filling the titanium tubing with solder, tin or almost any other metal; that the heating issues are reduced to easily manageable levels.

 

I've also enlarged the electrode size enough to give him a serious boost in reaction potential (more oxidizer production in shorter times). I expect he'll be happier with the whole setup and be able to make plenty of chlorate with his power setup.

 

He also mentioned his desire to build a second bucket cell with an LD anode for converting sodium chlorate to sodium perchlorate! It sounds like he has an exciting goal for his electrochemistry pursuits this year (I can't say I blame him ).

 

WSM

Edited April 30, 2020 by WSM

[fr3dopyrox]

I'm halfway through rebuilding the electrodes for a friend's bucket cell. In the first version, the leads were too small and heating was a serious problem.

 

I've since remade the leads and upgraded from 6 mm OD titanium tubing to 3/8" (~9.5 mm) OD tubing, and plan to fill the space inside with 1/4" (6.35 mm) OD solid round copper rod. I find the solid copper conducts electricity so much better than filling the titanium tubing with solder, tin or almost any other metal; that the heating issues are reduced to easily manageable levels.

 

I've also enlarged the electrode size enough to give him a serious boost in reaction potential (more oxidizer production in shorter times). I expect he'll be happier with the whole setup and be able to make plenty of chlorate with his power setup.

 

He also mentioned his desire to build a second bucket cell with an LD anode for converting sodium chlorate to sodium perchlorate! It sounds like he has an exciting goal for his electrochemistry pursuits this year (I can't say I blame him ).

 

WSM

hello , for the titanium tubing (9,5 mm) and the 6,35 mm od solid round copper : what is the length for this tubes ? Maybe do you have photos for this bucket cell ? Thank you very much..,

[WSM]

hello , for the titanium tubing (9,5 mm) and the 6,35 mm od solid round copper : what is the length for this tubes ? Maybe do you have photos for this bucket cell ? Thank you very much..,

 

 

The length was roughly long enough for the bottom edge of the electrodes to reach about 2" (~50 mm) above the bottom of the bucket; also to reach about 2" above the fittings in the lid. The spacing of the electrodes above the bucket bottom can be adjusted by loosening the compression fittings and moving the electrodes up or down as needed, before the cell is running.

 

Never try that while the cell is running or you'll most certainly short out the cell, and likely damage the power supply !

 

The description here is for a potassium chlorate cell, where the crystals will drop out of solution as the chlorate saturation increases. In a sodium chlorate cell there is no concern about crystal accumulation at the bottom of the cell, so adjustment of the electrode height is unnecessary.

 

To promote even heating in the cell, place the electrodes as low in the cell as possible so the "hydrogen lift" from hydrogen gas forming at the cathodes and rising to the surface of the electrolyte, will encourage a convection-like flow of the liquids in the cell as it operates. If this isn't done, you may notice that the top portion of the cell is warmer than the bottom, and the cell efficiency will suffer.

 

WSM

Edited October 12, 2020 by WSM

[pyrojig]

I'm halfway through rebuilding the electrodes for a friend's bucket cell. In the first version, the leads were too small and heating was a serious problem.

 

I've since remade the leads and upgraded from 6 mm OD titanium tubing to 3/8" (~9.5 mm) OD tubing, and plan to fill the space inside with 1/4" (6.35 mm) OD solid round copper rod. I find the solid copper conducts electricity so much better than filling the titanium tubing with solder, tin or almost any other metal; that the heating issues are reduced to easily manageable levels.

 

I've also enlarged the electrode size enough to give him a serious boost in reaction potential (more oxidizer production in shorter times). I expect he'll be happier with the whole setup and be able to make plenty of chlorate with his power setup.

 

He also mentioned his desire to build a second bucket cell with an LD anode for converting sodium chlorate to sodium perchlorate! It sounds like he has an exciting goal for his electrochemistry pursuits this year (I can't say I blame him ).

 

WSM

[pyrojig]

If say you are correct. A cell capable of multiple functions (chlorate and perchlorate production)

I find k salt to be straight forward For chlorate production(, with the minor inconvenience adjusting of the electrodes).

Na salt at first seemed difficult , but with the solubilities in favor, it allows almost a seemless transformation of the chlorate to perch. This could easily be done either with a quick adapter for changing electrodes , or simply a separate BCA/ lid arrangement to swap tops. A connection to the power supply and off you go , while the brine is hot. This keeps solution to max solubility, and no loss in energy to re-heat the liqueur

[pyrojig]

WSM quote "Never try that while the cell is running or you'll most certainly short out the cell, and likely damage the power supply !"

 

Lol , never did that before !

Ok, maybe once.. I was thankful it was only a pc power supply, I was fortunate to have access to more through a repair shop ( free) I just asked to dig through their scraps and trash .

[Arthur]

If you have a MMO cell could you feed it with brine through a peristaltic or bellows (iwaki!) pump and let overflow go into another vessel. This second vessel could be a cooling tank, then the cooled liquor from cell 1 would pass into cell 2 with a lead dioxide/Pt electrode, and when that cell overflowed perc laden solution would pass onto a recovery system. After the intended product is removed the wastes from cell 1 & 2 could pass into a tank to be resaturated with chloride and the process continued. Use a computer controller to control the rate of brine introduction and the current in each cell.

[WSM]

If say you are correct. A cell capable of multiple functions (chlorate and perchlorate production)

I find k salt to be straight forward For chlorate production(, with the minor inconvenience adjusting of the electrodes).

Na salt at first seemed difficult , but with the solubilities in favor, it allows almost a seamless transformation of the chlorate to perch. This could easily be done either with a quick adapter for changing electrodes , or simply a separate BCA/ lid arrangement to swap tops. A connection to the power supply and off you go , while the brine is hot. This keeps solution to max solubility, and no loss in energy to re-heat the liquor

 

 

The simplest setup for sodium chloride to sodium perchlorate was described by researchers from India. They made their own GSLD (graphite substrate lead dioxide) anode. It used a small amount of sodium fluoride in the electrolyte to help it work (which it did).

 

If someone were to attempt it with an LD-on-titanium anode, the fluoride would destroy the anode titanium substrate, and the system would fail.

 

I think running sodium chloride-chlorate-perchlorate steps separately, with all the required purification and crystallization steps in between, would offer the greatest likelihood of success. Removing sodium residue contamination from any potassium perchlorate produced from the sodium perchlorate would be the (most important) final step before drying and storing the KClO₄ produced.

 

WSM

[pyrojig]

Good point , I guess any remaining chlorides if present would kill the platinum quickly. So, I see the value of purifying being a necessary step.

[WSM]

Good point , I guess any remaining chlorides if present would kill the platinum quickly. So, I see the value of purifying being a necessary step.

 

If I remember correctly, the higher the chloride content of the electrolyte solution, the faster the degradation of the platinum (while the cell is running).

 

I found it best to make and harvest dry sodium chlorate crystals, then make an electrolyte from them with distilled water to run in a current controlled (constant current, or CC) perchlorate cell.

 

After the calculated run time for the perchlorate solution was achieved (and the electrodes removed), the residual chlorates were destroyed by adding sodium metabisulfite solution, deep under the surface of the solution, and slow enough to prevent the sulfur dioxide (that is formed and doing the work of chlorate destruction) from flashing off. When the perchlorate solution tests chlorate-free, then add the potassium chloride solution to drop out fine powdered KClO4.

 

WSM

Edited November 15, 2020 by WSM

[WSM]

If you have a MMO cell could you feed it with brine through a peristaltic or bellows (iwaki!) pump and let overflow go into another vessel. This second vessel could be a cooling tank, then the cooled liquor from cell 1 would pass into cell 2 with a lead dioxide/Pt electrode, and when that cell overflowed perc laden solution would pass onto a recovery system. After the intended product is removed the wastes from cell 1 & 2 could pass into a tank to be resaturated with chloride and the process continued. Use a computer controller to control the rate of brine introduction and the current in each cell.

 

 

This type of system works on an industrial scale but would be high priced and cumbersome on an amateur scale, requiring expensive controls and sensors. The continuous running IS attractive, though for high production.

 

I find doing steps separately allows for purification steps and easier control of the quality of the final products. We amateurs have the luxury of time over cost unlike the commercial producers.

 

WSM

[WSM]

I like the simplicity and convenience of the bucket cell design that Swede promoted. My first attempt at chlorate making involved a 5 gallon plastic bucket, but my setup was faulty and failed miserably, leaving me a toxic mess to deal with.

 

I later had success using a one gallon glass pickle jar with a large PVC pipe cap for a lid.

 

Swede's innovation was the BCA, or bucket cell adaptor, which is a 3/4" (~20 mm) thick piece of PVC plate bolted to the top of the bucket lid as a carrier for the various fittings and adaptors for the electrodes, vent and sundry other desired sensors/controllers to make the system function as desired.

 

My research in this area took a serious turn when I turned my attention to making sodium chlorate for the starting material for a perchlorate cell.

 

I decided to attempt duplicating a US Patent (shared by Arthur) describing an efficient, high-temperature sodium chlorate cell for making large amounts of sodium chlorate in less time using less energy and effort. The idea is attractive for making lots of NaClO₃ as a starting material for continuing my research into potassium perchlorate production on an amateur scale.

 

In that effort, I resolved to use a heavy walled, 5 liter laboratory reaction flask for a cell, with a 1" (25 mm) piece of Teflon (PTFE) plate for a lid. I've gone so far as to build a support structure to hold the borosilicate glass reaction vessel and Teflon top plate together with minimal tension. My work toward the effort has been on hold due to lack of available time because of work and family concerns. The project is sitting on a work bench in my workshop, and will resume when I can get back to it.

 

In the interim, I'm seriously considering running a modified bucket cell with a prototype BCA and make some potassium chlorate from purified KCl water softener salt. My hope is that after the extra effort of purifying the starting material, I'll be able to easily make a high quality KClO₃ through a direct process! We'll see...

 

WSM

Edited April 8, 2021 by WSM

[pyrojig]

Wsm I believe it is worth the effort to run a test in the bucket cell for na-clo3

[WSM]

Wsm I believe it is worth the effort to run a test in the bucket cell for na-clo3

I believe so, too. If I had the time, I'd give it a try...

 

WSM