making potassium (per) chlorate

[Arthur]

To achieve perchlorate one needs either a Beta Lead Dioxide electrode, or a platinum electrode. Sadly platinum is an expensive metal even as a surface coating, and though alpha lead dioxide is easy to source the beta form is not either easy to source or trivial to make.

 

Currently we have the skills to make chlorate because the electrode choices are simple, available and cheap. As yet we do not have Perc making facility because the anode material is hard to come by, or silly expensive, or toxic.

 

Should perc ever really disappear from hobbyist sale then no doubt the more resourceful among us will either afford platinum electrodes or solve the lead dioxide difficulties.

[WSM]

To achieve perchlorate one needs either a Beta Lead Dioxide electrode, or a platinum electrode. Sadly platinum is an expensive metal even as a surface coating, and though alpha lead dioxide is easy to source the beta form is not either easy to source or trivial to make.

Currently we have the skills to make chlorate because the electrode choices are simple, available and cheap. As yet we do not have Perc making facility because the anode material is hard to come by, or silly expensive, or toxic.

Should perc ever really disappear from hobbyist sale then no doubt the more resourceful among us will either afford platinum electrodes or solve the lead dioxide difficulties.

 

About two years ago, Swede made a fairly decent, beta form PbO₂ electrode. He fully explained what he did in his blogs. The plating bath was large and he had to build a few critical pieces of lab gear to do it, but he plated a heavy coating on a piece of MMO mesh. The LD didn't stick very well to the titanium substrate (at the cut edge of the MMO mesh) but stuck very well to the MMO. I imagine if you had the ability to do a decent MMO coating on titanium or had access to a place that could do it; you could make a titanium electrode, have the MMO coating done and then put it in the LD plating setup and have a decent LD anode.

 

I'm not ready to go there myself, but who knows what the future holds?!

 

WSM

[WSM]

I had some time to do electrical/electronics projects and repairs so I took some meters I collected and assembled a voltage and current display to use with one of my cell projects.

 

 

Of all the digital meters I've collected (most of them LED displays), I think I like the LCD meters with the blue background the best. They are easy on the eyes and consume less power, I think. The hardest part (besides getting the meters in the first place), was cutting the PVC electrical box I got at the Big Box Home Center to place the meters in.

 

I layed out the dimensions of the meters on the inside of the lid after accurately measuring the meters. I then drilled eight 0.1875" (3/16") holes near the corners of where the meters will go. Next, I used a coping saw to rough-cut the meter holes. Then, using a medium rough file, I removed most of the material so I could fit the meters tightly into the lid of the PVC box. After mounting the meters, I layed out the terminal strip and drilled holes to match the leads going into the meter box, and drilled and tapped holes for the mounting screws to attach the terminal strip to the meter box. All that remained was to solder the leads from the meters to the terminal strip and close the box.

 

Now all I have to do is set up the power supply with the shunt for the ammeter and wire it all together, and it's ready to work.

 

WSM

[pyrojig]

Very nice...

 

 

It is nice to see this project moving . Keep us posted on the goods....

 

If I recall ....those box's arnt thin...must have been fun hacking through that thick plastic

[oldmanbeefjerky]

i gotta find me a box like that to put my ammeter and stupidly small (15mm x 25mm) 0-99v voltmeter, but attach the lot to a big board of terminals for the individual outputs of the ATX, since it doesnt really look that nice, at the moment, since ive just bunched up all the same colour wires and left it at that.

Honestly right now ide even build the lot from wood if i could find some resources!

[WSM]

Very nice...

It is nice to see this project moving . Keep us posted on the goods....

If I recall ....those box's arnt thin...must have been fun hacking through that thick plastic

 

I will post the progress, but it'll take a while. I'd rather build it right than fast. The plastic is thick (nearly 5mm), but cuts easily if you have the right tools on hand.

 

I confess; I'm a weird duck. Three things get me excited; books, tools and chemicals. I bet I'm not alone...

 

WSM

[WSM]

i gotta find me a box like that to put my ammeter and stupidly small (15mm x 25mm) 0-99v voltmeter, but attach the lot to a big board of terminals for the individual outputs of the ATX, since it doesnt really look that nice, at the moment, since ive just bunched up all the same colour wires and left it at that.

Honestly right now ide even build the lot from wood if i could find some resources!

 

I get them from the "Big Box Home Center" (un-named large hardware store) in the electrical section. They're used for electrical circuits in wet areas and I think they're made of hard PVC plastic. They're a little expensive but compared to the cheap quality project boxes (for more money) at the electronics store, they're a bargain! Plus, they're tough.

 

They're not that expensive; I payed more for the meters and other parts by many times, and it seems like a good investment to protect them.

 

Now a good way to connect all those wires from the ATX power supply is to run each wire of the same color to a copper bus (a larger conductor of solid copper) and separate busses for each color. Now feed the cell from those busses with large cables bolted on the busses and on the electrodes. It works for industry, I know it'll work for you. It's important to cover the buswork to protect persons and property from injury or damage. A piece of larger diameter PVC pipe (any thickness) can cover things and is an excellent insulator. Think outside the box; but, think safety first.

 

WSM

Edited October 29, 2011 by WSM

[WSM]

Hi Arthur,

This approach may work with a conditioned cell, but the first run when you're turning the salt solution into mother liquor (hypochlorite, etc.) wouldn't be the same as when running a recharged cell after the initial run. Yours sounds like a reasonable approach, though. I like it. (and I can finally get around to using that pair of titration columns gathering dust in the shop!)

I do have peristaltic pumps and metering pumps I can use. I wanted to try the gravity-fed system first, though. I imagine it will be the most economical to run.

I did find a source for the Iwaki KB type bellows pumps from a surplus source. I'm waiting for a return message from the seller before I commit to getting any. Thanks for the heads-up.

WSM

 

Hi Arthur,

 

I was contacted by the seller and we struck a deal. I'm getting six of the bellows pumps and also found a new Iwake controller for the same pumps; all for just a bit over $100 US. I will try to keep everyone informed of these pumps and my opinion of their suitability for cell use. They look good (enough that I committed to buy several) but I'd like to evaluate them in practice before I whole-heartedly endorse their use.

 

WSM

[oldmanbeefjerky]

.

 

Now a good way to connect all those wires from the ATX power supply is to run each wire of the same color to a copper bus (a larger conductor of solid copper) and separate busses for each color. Now feed the cell from those busses with large cables bolted on the busses and on the electrodes.

 

 

thats the plan

[Bonny]

Now a good way to connect all those wires from the ATX power supply is to run each wire of the same color to a copper bus (a larger conductor of solid copper) and separate busses for each color. Now feed the cell from those busses with large cables bolted on the busses and on the electrodes. It works for industry, I know it'll work for you.

WSM

 

Seems like a lot of effort and material expense to go through. Simply twisting the same colours together and joining to the (preferably stranded) copper cable by soldering is all that's needed. The wire size required for 25A (for example) is not that big, and in commercial/residential electrical, connections are made by twisting only, or (shudder) with marrets only!

If you are using ATX power supplies, then it seems pointless to do "high end" connections!

Edited October 30, 2011 by Bonny

[WSM]

Seems like a lot of effort and material expense to go through. Simply twisting the same colours together and joining to the (preferably stranded) copper cable by soldering is all that's needed. The wire size required for 25A (for example) is not that big, and in commercial/residential electrical, connections are made by twisting only, or (shudder) with marrets only!

If you are using ATX power supplies, then it seems pointless to do "high end" connections!

 

Sorry. I always start large and work my way down. For my small test last July, I used a 5Vdc 30A power supply and fed the cell with a single pair of 10 gage stranded copper leads with crimped ring connectors bolted on at either end. They worked fine and very little heat was noticed (except inside the cell). I do have power supplies that can deliver higher currents of between 60A to as high as 150A. My thinking is always of the worst case or the greatest potential and prepare for that.

 

With a small power supply delivering limited current, much smaller conductors are required. Good connections and "large enough" conductors are all that is required. I strongly suggest avoiding aligator clips to connect your electrode leads to the power source, preferring bolted connections for more efficient power transfer. Stainless steel hardware will hold up better than mild steel or brass, particularly where the cell connections are made.

 

If you set up for the biggest power supply you ever anticipate using, the smaller ones will work with it. It is overkill, but will pay off if or when you upgrade the system. My electrical training has me always thinking of future possibilities. I tend to leave room for improvements or add-ons.

 

WSM

[Bonny]

Sorry. I always start large and work my way down. For my small test last July, I used a 5Vdc 30A power supply and fed the cell with a single pair of 10 gage stranded copper leads with crimped ring connectors bolted on at either end. They worked fine and very little heat was noticed (except inside the cell). I do have power supplies that can deliver higher currents of between 60A to as high as 150A. My thinking is always of the worst case or the greatest potential and prepare for that.

 

With a small power supply delivering limited current, much smaller conductors are required. Good connections and "large enough" conductors are all that is required. I strongly suggest avoiding aligator clips to connect your electrode leads to the power source, preferring bolted connections for more efficient power transfer. Stainless steel hardware will hold up better than mild steel or brass, particularly where the cell connections are made.

 

If you set up for the biggest power supply you ever anticipate using, the smaller ones will work with it. It is overkill, but will pay off if or when you upgrade the system. My electrical training has me always thinking of future possibilities. I tend to leave room for improvements or add-ons.

 

WSM

 

I agree that it is best to build with room for improvements, but buss bars seem a bit excessive using smaller power supplies. Most amateurs are unlikely to ever be building 100A set ups.

And you're right about the alligator clips, they are a crappy way to connect anything that will have significant current flow. I always bolt my connections (wire to electrode), but my power supply wires are soldered to the extension cables.

 

On another note, I ordered a small power supply with voltage and amperage adjustment. It only puts out 5A, but will be fine for small scale (perc ONLY) production. Sometine this winter I'll set up another cell. I still have several Kg's of perc that needs cleaning. I'm not sure if my LD anode from Patsroom will still work, I think the coating was eroded during my last (and only) run. I'll probably have to try and find another one. Although I've made a fair amount of perc, I've toasted all of my anodes in the process

[Bonny]

I'm looking for ideas here...

 

IF my LD anode is NFG, I'll be getting another Pt anode. I think part of the reason I've fried the last 2 Pt anodes is due to the low chlorate concentration in my (PERC cell). I am using KClO3 as feedstock and have NO INTENTION of going to sodium salts.

I am considering dichromate, although I don't want to, but Pt anodes are $$$.

Cell is an 18l HDPE pail.

What I was thinking, is to add a suspended mesh bag or perforated container filled with chlorate into the cell . The perc precipitates out as it is formed so (not too much) chlorate should end up in the bottom. I would also use my air bubbler to add some circulation. I'm sure Swede or has WSM mentioned something like this before.

This way, I can run the cell for a (to be roughly calculated) time w/o as much anode damage.

The perc would still need cleaning, but I do that anyway.

I do not have the time or resources for complicated multi-chamber cells (although they are nice). I am just looking for a simple , cheap and will do what I need without killing Pt($$$)anodes setup.

[WSM]

I'm looking for ideas here...

IF my LD anode is NFG, I'll be getting another Pt anode. I think part of the reason I've fried the last 2 Pt anodes is due to the low chlorate concentration in my (PERC cell). I am using KClO3 as feedstock and have NO INTENTION of going to sodium salts.

I am considering dichromate, although I don't want to, but Pt anodes are $$$.

Cell is an 18l HDPE pail.

What I was thinking, is to add a suspended mesh bag or perforated container filled with chlorate into the cell . The perc precipitates out as it is formed so (not too much) chlorate should end up in the bottom. I would also use my air bubbler to add some circulation. I'm sure Swede or has WSM mentioned something like this before.

This way, I can run the cell for a (to be roughly calculated) time w/o as much anode damage.

The perc would still need cleaning, but I do that anyway.

I do not have the time or resources for complicated multi-chamber cells (although they are nice). I am just looking for a simple , cheap and will do what I need without killing Pt($$$)anodes setup.

 

I don't know if dichromates are called for with perchlorate production, but a small percentage is helpful with chlorate making.

 

You could set up a bucket cell (ala Swede) and have a piece of, say, 50mm diameter PVC pipe run vertically down into the cell from the lid, with a cap on the bottom and many small holes drilled into the side (under the liquid level), so the chlorate dropped in it is constantly in contact with the cell liquor. It would self-feed the chlorate stock and you could periodically add chlorate as needed, from the top while the cell is running.

 

It's an interesting thought. Let us know if and how it works.

 

WSM

Edited October 31, 2011 by WSM

[WSM]

I agree that it is best to build with room for improvements, but buss bars seem a bit excessive using smaller power supplies. Most amateurs are unlikely to ever be building 100A set ups.

And you're right about the alligator clips, they are a crappy way to connect anything that will have significant current flow. I always bolt my connections (wire to electrode), but my power supply wires are soldered to the extension cables.

 

On another note, I ordered a small power supply with voltage and amperage adjustment. It only puts out 5A, but will be fine for small scale (perc ONLY) production. Sometine this winter I'll set up another cell. I still have several Kg's of perc that needs cleaning. I'm not sure if my LD anode from Patsroom will still work, I think the coating was eroded during my last (and only) run. I'll probably have to try and find another one. Although I've made a fair amount of perc, I've toasted all of my anodes in the process

 

True, but wouldn't it be nice to be able to?! Just a thought...

 

WSM

[WSM]

Seems like a lot of effort and material expense to go through. Simply twisting the same colours together and joining to the (preferably stranded) copper cable by soldering is all that's needed. The wire size required for 25A (for example) is not that big, and in commercial/residential electrical, connections are made by twisting only, or (shudder) with marrets only!

If you are using ATX power supplies, then it seems pointless to do "high end" connections!

 

Soldering is always preferred to mechanical binding (which can get loose). For a 25A circuit, 12 gage wire may work but 10 gage will more than do it and be less likely to heat up during operation. If 10 gage is hard to come by, doubling smaller gage wire will work. The trick is to match or exceed the "circular mills" (total cross section area of the wires) of the cable(s) required to conduct the current to the electrodes.

 

WSM

Edited October 31, 2011 by WSM

[frank]

@bonny

 

Would it be possible to upload a picture of the Lead dioxide anode.

A before (if you have one) and after would be great.

 

Has all the lead dioxide been eaten away?

[Bonny]

I don't know if dichromates are called for with perchlorate production, but a small percentage is helpful with chlorate making.

 

You could set up a bucket cell (ala Swede) and have a piece of, say, 50mm diameter PVC pipe run vertically down into the cell from the lid, with a cap on the bottom and many small holes drilled into the side (under the liquid level), so the chlorate dropped in it is constantly in contact with the cell liquor. It would self-feed the chlorate stock and you could periodically add chlorate as needed, from the top while the cell is running.

 

It's an interesting thought. Let us know if and how it works.

 

WSM

 

Regarding the dichromate, the references are here:

 

 

The references are here:

 

http://oxidizing.110mb.com/chlorate/naperchl.html

 

I highly suspect that my Pt was eroded by low KClO3 concentrations, and maybe the presence of chloride, although the feedstock was recrystallized.

 

With the solubility of KClO3 being so low, I think it is almost unavoidable without keeping a "stock" of chlorate in the cell to be dissolved as the cell runs. As I don't care much about efficiency, I'm not worried about wasting some additional chlorate that could end up on the bottom of the bucket with the perc.

 

Here's a pic of the anode. Although difficult to see, there is obvious erosion of the coating. When it was new it had an almost "fuzzy" surface. There are now spots showing the wire substrate.

Edited November 1, 2011 by Bonny

[WSM]

Hi Arthur,

I did find a source for the Iwaki KB type bellows pumps from a surplus source. I'm waiting for a return message from the seller before I commit to getting any. Thanks for the heads-up.

WSM

 

My box of pumps arrived yesterday. They are definitely pulled from photofinishing equipment and the bellows are full of smelly liquid to prove it. I set up a power cord and removed as much of the residual liquid as possible and proved the pumps worked. Their function is similar to the diaphragm pumps I build.

 

More later...

 

WSM

[gregkdc1]

Hello to everyone on the forum.

First let me say that I am just your average forum noob that day dreams about making perchlorates. I am also an armature rocket enthusiast from way back, and eventually would love to make perchlorates. I know that it would be easier, cheaper and safer to buy perchlorates but where would the fun be in that. After all if we applied that same logic to pyrotechnics this forum probably wouldn't be here.

Anyways I have been studying and reading any info I can find on the web about making chlorates and preferably perchlorates for the last 6 months or so. Through everybody else’s experiments, successes and failures I have come to the same conclusions that most people do and that is you need either Lead dioxide or platinum anodes to make perchlorate. Lead dioxide is cheap and unreliable and platinum is obviously priced out of reach to be worth while. One thing that I haven't found a lot of information about is the thermal production of perchlorate form chlorate. Why is this? Is it due to safety factors, or is it harder than you would think? From what I have found it looks like it might be a viable way of making potassium perchlorate, but because of chlorate contamination and solubility issues not so great for other salts like AP. I found this interesting article that some of you may or may not have read. http://www.dtic.mil/dtic/tr/fulltext/u2/003174.pdf I find it fascinating that the reaction is slightly exothermic once it gets going and that the chlorate/perchlorate are in equilibrium. Under those circumstances it is hard to believe that nobody has found out a way to catalyze the reaction. The big question is where does a person find an inexpensive 500 c oven to convert the chlorate. Also I wonder what would happen if you added lithium chlorate to create a lower melting eutectic, this should be able to melt in a standard oven, would the chlorate still auto oxidize? My guess is probably yes but it may take weeks to months to do so? Does anybody have any first hand experiance with this? If so any info would be greatly apreciated. Thanks

 

 

[frank]

Be the lord blessus and save us Bonny. That's one bad picture. Do you have a scanner? If your camera is broke (or you cannot work it) it would be better to give us a scan of the Anode!

 

Frank

[Bonny]

Be the lord blessus and save us Bonny. That's one bad picture. Do you have a scanner? If your camera is broke (or you cannot work it) it would be better to give us a scan of the Anode!

 

Frank

 

 

Damn, I didn't realize it was that bad until I opened it up...seemed to look OK through the lens. My camera is a piece of shit. I'll try scanning tomorrow if I remeber to bring the anode to work. Hopefully it turns out better.

[oldmanbeefjerky]

Hello to everyone on the forum.

First let me say that I am just your average forum noob that day dreams about making perchlorates. I am also an armature rocket enthusiast from way back, and eventually would love to make perchlorates. I know that it would be easier, cheaper and safer to buy perchlorates but where would the fun be in that. After all if we applied that same logic to pyrotechnics this forum probably wouldn't be here.

Anyways I have been studying and reading any info I can find on the web about making chlorates and preferably perchlorates for the last 6 months or so. Through everybody else's experiments, successes and failures I have come to the same conclusions that most people do and that is you need either Lead dioxide or platinum anodes to make perchlorate. Lead dioxide is cheap and unreliable and platinum is obviously priced out of reach to be worth while. One thing that I haven't found a lot of information about is the thermal production of perchlorate form chlorate. Why is this? Is it due to safety factors, or is it harder than you would think? From what I have found it looks like it might be a viable way of making potassium perchlorate, but because of chlorate contamination and solubility issues not so great for other salts like AP. I found this interesting article that some of you may or may not have read. http://www.dtic.mil/dtic/tr/fulltext/u2/003174.pdf I find it fascinating that the reaction is slightly exothermic once it gets going and that the chlorate/perchlorate are in equilibrium. Under those circumstances it is hard to believe that nobody has found out a way to catalyze the reaction. The big question is where does a person find an inexpensive 500 c oven to convert the chlorate. Also I wonder what would happen if you added lithium chlorate to create a lower melting eutectic, this should be able to melt in a standard oven, would the chlorate still auto oxidize? My guess is probably yes but it may take weeks to months to do so? Does anybody have any first hand experiance with this? If so any info would be greatly apreciated. Thanks

 

 

 

I wouldnt expect lithium chlorate to help, being a liquid it would help to transfer the heat better to make the chlorate melt sooner, but thats it. im fairly certain that this reaction needs the same heat whether or not the chlorate is already molten.

I have seen some heat fans capable of blowing 600c hot air with only 45 seconds of warm up time. clearly nichrome can reach in exess of 500c , so why not try building your own? all you need is some clay and or asbestos and some sheet metal for structure and some thick nichrome, possibly surrounded with something like fiberglass to guard it from the air.

 

Im sure others here will know a bit more than i do on this. but so far, im seeing it easier to use lead dioxide or platinum than to do it with heat.

 

That reminds me,

im going to try coating some pool chlorinator anodes in lead dioxide, required they even function since im salvaging them from broken chlorinators. should i try plating the broken MMO anodes, or would i be better off just putting a thin layer of MnO2 and Cobalt oxide on the titanium cathodes or anodes (with the MMO removed), then plating them in lead dioxide? turns out the pool shop near me gets on average 1 chlorinator cell in each week for repairs, but end up getting tossed out and replaced. Lucky me!

[WSM]

im going to try coating some pool chlorinator anodes in lead dioxide, required they even function since im salvaging them from broken chlorinators. should i try plating the broken MMO anodes, or would i be better off just putting a thin layer of MnO2 and Cobalt oxide on the titanium cathodes or anodes (with the MMO removed), then plating them in lead dioxide? turns out the pool shop near me gets on average 1 chlorinator cell in each week for repairs, but end up getting tossed out and replaced. Lucky me!

 

Hi OMBJ,

 

Why don't you try the MMO anodes in a chlorate cell first and see how they compare to the laserred anodes. My thinking is, if they'll make chlorate they ought to be able to be plated with LD. It's worth a try.

 

WSM

[gregkdc1]

For the oven I already have an old hot plate that I can scavenge the heating element and the dial for temp control. There is a ceramics store down the road from my work that sells insulating firebrick for a decent price. As you said the body can be made out of sheet metal or even angle iron just to hold the bricks together. My main hold up right now is what should I use to measure the heat, at a decent price? There are lead casting thermometers that look ok but I don't know how accurate they are. Also you can some times find a digital infrared thermometer for cheap, but this will necessitate an opening into the oven. When you talk about it being easier to make lead dioxide anodes instead of using heat I am not exactly convinced. From what I have read they don't last long, and it can be quite a process just to make one, including making all of the precursor chemicals like lead and copper nitrate. I think the biggest disadvantage to using the heat method is safety and efficiency but I am not concerned too much with efficiency. I think it may actually be an easier way to make perchlorate and faster if what is stated in the pdf I referenced is true. That is why I am here to see if any body else has first hand experience before I move forward.