Alan,

I have been very interested in producing Potassium Perchlorate for Blue Stars. It is very expensive online and new regulation makes it harder to get good amounts. I have tried to make sense of it all but there is a lot to take in. If you could lead me in the right direction it would be greatly appriciated,

Thanks,

Cal

NurdRage has made a good video on making MnO2 electrodes at home. He makes his own chemicals, too:

Alan,

This is a remarkable collection of material and you deserve congratulation. We are trying to sort out electrodes to use for liquid conductivity measurement so the need is for stable surface properties and long life at low current density. Graphite and "activated titanium" (is that MMO Ti?) seem to be the best prospects but suppliers are not easy to find. We have two local sources of the activated Ti but quality is questionable. Any suggestions would be appreciated.

Hi Alan,

Great work you've done here! Im currently atempting to produce sodium chlorate using a graphite anode. Before running the cell, I treated the anode with linseed oil, then cured it in the oven. I've run the cell now for about 3 days, and while there is quite abit of suspended graphite in the solution, the anode appears to be in fairly good shape, very little corrosion (although I am keeping the current desity quite low, about 30mA per square centimetre.) Have you every tried treating graphite anodes before use? One thing Im worried about is contamination of the final product, but I'll see how that goes...

The electrodes do not recover, even when the supply is switched back to 5 volts. I've got silver paint over the lead dioxide, and copper wire clamped in place with small G-clamps over the silver paint. When the G-clamp is released, the wire moved around a little, and the clamp tightened, the current goes back to what it originally was. I think my problem lies in the connection at the anode. Thanks for the help. Your site's a wealth of info.

Jack,

I didn't do anything special cell wise, the electrode spacing was quite close though, about 6 mm. The electrodes came with a slotted retainer frame, I used two adjacent slots. The cell resistance changes with electrode spacing and area, temperature, liquor concentration, etc... It is very hard to achieve a constant current passively, you really need an active current limiting PSU - I've never bothered except on very small experimental cells where the dissipation in the electronics is mild enough to use primitive linear regulation. A constant current supply for huge currents would be best made switching especially as efficiency becomes more important scaling up, the main cost is electrical energy. No doubt worthwhile if you are serious about reliable larger systems and cheap operating costs.

Yes the total loop resistance has to be very low to achieve high currents at a voltage like 5 volts. For 50 amps it has be 100 milli-Ohms. I used relatively short and very thick cabling (8 gauge) soldered directly to the power supply's output pads and chunky alligator clips also soldered to the cabling. Even the shunt connections were via soldered-to jumbo hardware with star washers, etc.

That all may have been overkill, I suspect the cell and the Titanium hardware in particular are the main resistance in the loop. Almost the full five volts appears across the cell risers. Better that your losses outside the cell are minimised of course, if for no other reason that efficiency. You can raise the voltage to push more current through a larger loop resistance, but if the cell represents only a small fraction of that resistance the efficiency will be terrible (on top of the poor electrochemical efficiency of uncontrolled cell pH, temperature, concentration, etc).

Consider that at 5 volts and 50 amps there is 250 watts going into the system. Small losses can cause significant heating outside the cell, but in my experience once you've reduced the ohmic interconnection losses sufficiently to achieve high currents (at low voltages) the cell becomes the main resistance and liquor heating a major limiting factor. It takes about 2.6 MJ to boil out a litre of water (i.e. get it to 100 C from ambient and then vapourise it). 250 watts will supply that in less than 3 hours. Fortunately losses to the ambient and actual electrochemical "losses" will mean the heating is a lot slower than that and depending on the geometry of the cell (surface/volume ratio and ambient conductivity in particular) the cell will stabilise at some elevated temperature where the ohmic dissipation balances the energy loss to the ambient. Hopefully the stable temperature will be only moderate, something that won't melt the cell or be high enough that evaporation is a major problem.

The guys that do this and other electrochemical synthesis commercially have clearly crunched the numbers and done everything they can to make the process as efficient as possible. Their main cost in the enormous amount of electricity required. Heating is bad news and active cooling even worse.

With the big current drop after application of 12 volts, do the electrodes recover, or is it an indication they are being damaged? Connections to Lead Dioxide are apparently pretty hard to maintain, Silver epoxy might be worth a try. It could also be the supply folding back protecting itself, depending on its design.

Regards,

Alan

Hi Alan. How do you get your cell to run at 50 amps? What is the cell volume? I'm running a 3 litre cell with ceramic substrate lead dioxide anodes, but the maximum current I can get on 5V is about 7 amps. When I increase to 12V the current goes way off my ammeter (only have a 10A one) then falls to about 0.5A. I suppose the connections to the electrodes could be the problem. Do you know what the approximate resistance of the electrolyte is?

Thanks.

Dave,

Yes you can use salt-substitute KCl/NaCl mixtures. Either way will work, precipitating out KClO3 after a cell run on pure NaCl, or with the mixed liquor.

It works especially with for Perchlorate, the vastly different solubilities of the Sodium vrs Potassium species makes it very easy to use up almost all the Potassium ions you add. For Chlorate the solution has to be fairly concentrated.

The main problem is the extra work required to get all the stray sodium out. Running with pure KCl makes it much easier to make fairly pure KClO3 in just one step.

You may be able to find Potassium Chloride as a fertiliser. I got a 25 kg bag of 'Water Soluble Muriate of Potash' quite cheaply. It was fairly pure, sugary white fine crystals. Some fertiliser grade material is mixed with binders, but the 'WS' (water soluble) stuff should come relatively pure.

Regards,

Alan

Dear Alan,

Could Potassium chlorate be made by using "low sodium salt" sold in supermarkets? (66% KCl, 33% NaCl) Would it be better to attempt to separate the potassium chloride from the salt, or run the cell with it not separated and obtain the precipitated Potassium chlorate? Ideally, I would like to use pure(ish) potassium chloride, but I can't find much of it in the UK.

Paolo,

I was given my MMO electrodes, so they cost me nothing. I imagine they are moderately expensive to purchase. A pool chlorinator rebuild costs about $100 AUD retail, the material is likely a reasonable fraction of that. I have no precise data on their current density limits, other than typical assemblies run at 25 Amps or more.

My Pt/Ti anode came from an casting alloys and plating provider here in AU.

The anodes from that ti-shop site look pretty similar. I would think the mesh anodes would be cheaper as they have less total surface area and that is what is plated with the much more expensive Pt or MMO material. The Titanium itself is not all that costly.

I read a while back in an electrochemical text that mesh anodes allow better gas flow and turbulent mixing which improves efficiency a small amount. The particular article was not about Chlorate cells however. Personally I'd go for surface area if the price is the same, as that lets you run more current and hence make more product.

Current density wise the plating material has this property, the absolute area it covers is what gives the anode its current handling. A plate with more area but the same plating can take more current. Be aware that it may be specified by "anode area" (a simple rectangular measurement of the anode size) not its actual surface area. With thick plates the edges of the holes can mean is has *more* surface area than a flat plate.

Regards,

Alan

Dear Alan,

by reading again and again your pages I always learn something new.

1)I'm checking the web for MMO and platinized Ti anodes.. I would like to know where did you get yours from and how much did they cost.

2)An english site, ti-shop.com, sell anodes stating that maximum currents are 0,3-0,5 A per squared cm for platinum plated (1micron) and 1,5 A/sqcm for MMO, what about yours?

3)pt-Ti and MMO-Ti mesh are much more expensive than the simple sheets. Is mesh so much better or can one just use sheets?

4)For the sake of saving money, If one get a MMO and a Pt anodes, could he use the pt as a cathode for the chlorate cell and the MMO as a cathode

Thanks a lot

Paolo

Anton,

Indeed, purifying the result was difficult. I ran the cell until it was quite inefficient (most of the Chloride converted) then recrystalised it several times. The yield wasn't very good, but the quality was OK as I used no Sodium at any point (except contamination in the HCl).

I made some Barium Chlorate/Shellac green composition with it. Very nice colour indeed. I didn't try pillboxes, just stars and lances.

There are probably better methods (yield wise) using Sodium Chlorate, but I suspect getting all the Sodium out is difficult.

Regards,

Alan

Hi Alan, Firstly great site. You showed a single photo of your barium chlorate cell and as far as I can see wrote nothing of your results. I have several hundred grams of BaCl2 which I intend to put into a cell similar to my sodium chlorate cell. Looking at the BaCl2 and Ba(ClO3)2 solubility curves, however, they are not too dissimilar which I guess means difficulty in separating them by fractional crystallisation. I could imagine running the cell and obtaining a high ClO3/Cl ratio and then concentrating by boiling and taking a small crop of Ba(ClO3)2 off and putting the remainder back in the cell.

Any comments/thoughts?

Cheers, Anton

Paolo,

Drawing pencils are generally graphite powder bound with clay. The ratio of clay to graphite determines the hardness, harder pencils have more clay and less graphite.

The really soft ones can be very conductive, but almost all drawing pencils will fall apart very quickly in the cell because they basically aren't waterproof. The cell environment is extremely erosive anyway and something which is just pressed together clay and graphite will turn to sludge in minutes. Some are sintered at a high temperature not just pressed warm and will last a bit longer, I suspect that is the kind I found. The binding clay still falls apart, but in hours to days rather than minutes.

You want the resistance to be a few Ohms at most. The pencils I tried had a varnish coating over most of their surface, probably to keep the artist's fingers clean in use. I sanded off that layer to get a good surface area. Silver loaded epoxy is a good way to make a connection to the graphite.

The idea of putting a filter around the anode is interesting. The anode gunk is very fine, so the filter would need to be extremely fine. Also the cell environment is quite corrosive, I'm not sure how long cotton would stay together. Try it and see I guess? A paste anode probably won't work, I can't imagine a material you could mix with or contact the graphite with that had sufficient conductivity and wouldn't just passivate or dissolve - otherwise that would be an interesting way to do it. Also, the membrane can't block ions or gasses, otherwise the reaction will be effected. Cells with membranes are used commercially to produce Chlorine and Sodium Hydroxide from Sodium Chloride. I'd imagine even a fairly coarse filter would have a pretty big efficiency hit.

The ideal graphite for a cell anode is the pyrolytic material. It is rather expensive though, so the granular/crystalline material that has been pressed under enormous pressure and moderate heat is more widely available. It is used widely in metallurgy and nuclear technology so it is fairly cheap and available is almost every conceivable shape.

Regards,

Alan

Michael,

I would never entertain the idea of selling my chemical supplies. Some idiot would injure themselves or someone else with them and cause a whole lot of trouble.

Depending on where in the world you live you might be able to buy the chemicals you are looking for, either online or over the counter. Being 15 years old may complicate things a bit, many suppliers want a purchase order from a company, then there is the payment, etc... Which suppliers specifically? Google or your local phone book is a good start.

I can't see why your mother wouldn't be fully supportive of a son interested in Chemistry. When I was your age my parents helped me buy chemicals and glassware, and tolerated my taking over the kitchen at times to cary out experiments. Of course you'll need to be open and honest about what you want to make and why.

I told my parents I wanted to make rockets and while cautious they had no major problems with it. I was in year 8 or 9 at the time IIRC. I was fortunate enough to find some Saltpeter in 50 g bags burried away in the back of a shop in China Town. That got me going to make BP and rockets. In many ways I was lucky I couldn't get Chlorates or Perchlorates, or find the information to create them myself. I suspect I may have had an accident from lack of knowledge otherwise, especially as most of the compositions I had researched were from Kentish or even older texts. With the internet now a beginner can find all the wrong information and source the chemicals to get themselves killed quite easily, but that said the safer methods are now much better documented and "resources" like the deliberately malicious cookbooks of old are dying off. All I had when I started was the encyclopaedias at the local and school Libraries.

Regards,

Alan

Dear Alan,

thanks for sharing your knowledge. I learnt a lot from your pages.

I'll try to take advantage your courtesy.

So, question is:

I bought a graphite rod from an artistry shop. It is intended for drawing. It comes in three grades: hard, medium, soft. Do you have any opinion in wich is the better to use?

Tester leads applied to the medium grade measured a fair high resistance, in the order of kiloOhms. Could it be just a matter of bad measurement?

Second question is:

Makes any sense contruct a cotton condom around the grapfite anode containing the anode itself and some cellulose to prevent carbon from the worn anode to go in the solution? I s there a better material suited to do the job?

Thank you

Paolo

Hi have you ever thought of selling some of the compounds you make, i am only 15 and having trouble locating some chemicals and elements required for pyrotechnics. even if i found some, for example "fertilizer" as used for Perchlorate and Sodium Chlorate, im sure my mum wouldnt apreciate me turning my bedroom into a chemical processing plant.

It would be much appreciated if you could give me some references on where i could buy some of these.

Thanx

Tony,

I only made high-purity Sodium Chlorate once, I didn't have any need for it and the process was a pain. I ran the Sodium Chlorate cell (using graphite electrodes) until there wasn't much Chloride left, which took its toll on the efficiency and the electrodes, but as they were graphite I didn't mind much. After filtration to remove the graphite I boiled down the liquor until Sodium Chlorate would crystallise on cooling. This let me extract most of the Sodium Chlorate without much Chloride also coming out. The resulting crystals were recrystallised several times (somewhat lossy, even with washing with ice-cold water) and then dried in a warm oven. The product didn't precipitate Silver Chloride at all.

Lots of work! In most Perchlorate runs I didn't bother with extensive recrystallisation, instead I just crashed the Sodium Chlorate out by boiling down and adding concentrated Sodium Chloride solution. Then I washed the Sodium Perchlorate with ice-cold water and added the washings back to the Chlorate cell liquor to minimise losses (boiling to re-concentrate as needed). The secret is to have a reasonably high Sodium Chlorate concentration before you try to extract any and not try to get all of the available Chlorate out. What you do get is almost pure and after a wash is fine for putting into a Perchlorate cell. Sodium Chlorate alone is very water soluble and you will have to make a fair bit before you have enough for a Perchlorate cell.

If you don't mind trashing Chlorate cell anodes or wasting power you can just run the Chlorate cell much longer than you would normally until the Chloride concentration is quite low, then swap anodes and run as a Perchlorate cell. To improve initial efficiency you can boil down the Chlorate cell liquor to concentrate it a bit first. I did that once and it didn't seem to hurt the Perchlorate cell anode. I filtered out the gunk between anode swaps too. I generally find running the Perchlorate cell too long does more damage to the anode than running it with a high Chloride concentration. Potassium Perchlorate is so easy to extract you might as well periodically dump it out and re-saturate with Sodium Chlorate if you are worried about anode life.

Oh yeah, Sodium Perchlorate is *very* soluble and nearly impossible to crystallise out. It is deliquescent and I simply couldn't crystallise it efficiently by evaporation, only by cooling it from a super-saturated solution could large amounts be crystallised. Not a big deal, it is basically useless except for making Potassium and Ammonium Perchlorate.

Regards,

Alan

Thanks for the great link Alan,

Would it be possible for you to document your purification process? Sorry for all the questions I just don’t want to have my Pt anode ruined with the first few runs.

Thanks,

Tony

Tony,

Pretty much yeah, except the co-solubility of Sodium Chloride and Sodium Chlorate complicates things a little. You can add Sodium Chloride solution to the liquor to "salt out" the Sodium Chlorate, or just boil it down a little. This page goes into detail the approaches you can take.

That whole website is an excellent resource, I highly recommend it to anyone making Chlorates or Perchlorates.

Regards,

Alan

Thanks for the reply Alan,

I still can’t seem to get my head around the removal and purification of the sodium chlorate is it as simple as just boiling of the solution a bit until you get chlorate crystallizing out?

Thanks again,

Tony

Tony,

You can purify the Chlorate by crystallisation, much as you would if you intended to use it as an end-product. Concentrated enough liquor of Sodium Chlorate can be crystallised, but I'll admit it is a pain compared to Potassium Chlorate.

No sense going too overboard to lots of nines though, some Chloride will be produced in the cell from the Chlorate by the electrochemical reactions forming the Perchlorate. Just make sure the feedstock is 'mostly' Sodium Chlorate to extend electrode life and improve efficiency. Purify it to the point that it only just precipitates Silver Chloride as an opalescent effect, not a milky cloud on addition of Silver Nitrate, much like my local tap water does.

Regards,

Alan

hi there alan,

i am contemplating bying a Pt/Ti anode for perchlorate production. i plan on using a MMO anode that i have been using for chlorate to run NaCl to NaClO3 and then running NaClO3 to NaClO4 using the Pt/Ti anode. but my question is how do you go about removing left over chloride from the chlorate before you start using the Pt/Ti anode as i belive this causes the anode to errode faster?

thanks tony

Hello Alan,

Thanks for reply. My last post was a bit vague on what I was trying to find out.

I am trying to find out if making Perchlorate with MMO (Not Platinum) is possible or feasible/sensible.

Did you make Perchlorate using MMO? You have stated towards the bottom of this page

http://www.vk2zay.net/article/146

that you have.

Was it an Na or K cell.

How long did the MMO last ie. how much product (Perchlorate not Chlorate) did you manage to make and/or how many amper hours did the MMO take (approx. current efficiency) before the MMO was considered destroyed.

Perhaps the MMO anode was not fully destroyed?

Do you have a figure (roughly) for current denstiy on the anode.

Did the MMO reduce the Chlorate to a low level of concentration in the cell do you know.

I appreciate that it was not last week that you done this stuff.

Thanks,

DM

Daniel,

Yes I made quite large quantities of Potassium Perchlorate, more than I ever purified to completely remove the trace Sodium to a point where it was usable for good blues. I did make and use high-purity Perchlorates for colour compositions, but I also used the relatively impure (couple of cycles of recyrstalisation) material for golden and silver wave compositions, shower sticks, perc-glitters, benzolift, etc.

I used Indigo Carmine to determine the Chlorate level, but the vast difference in solubility between Potassium Chlorate and Perchlorate makes it pretty easy to get most of the Chlorate out before you destroy any remaining. Sodium contamination was assessed by flame testing on a Platinum loop.

Regards,

Alan

At the bottom here http://www.vk2zay.net/article/146

you mention that you got good yields of K. Perchlorate (not Chlorate). Is this correct.

Did you run any checks for purity of final product etc etc.

Cheers

No, don't try to contain the gas. That's just asking for an explosion.

PE pretty much is just like a high-density wax, I wouldn't use it for containing anything corrosive it has poor chemical compatibility unless its surface has been floridated. I generally use polypropylene it is far more chemical resistant.

So I add barium carbonate to hydrochloric acid until it stops bubbling and then filter of any excess barium carbonate that was not dissolved, I then boil this down to remove the water from the barium chloride? Is this correct

Thanks again Julian

Julian,

I reacted some Barium Carbonate from a ceramics supplier with Hydrochloric acid from the hardware store. Sulfate contamination caused some Hydrogen Sulfide production (do it outside), but otherwise it was uneventful. Some recrystallisation purified the product. The foaming from the reaction might be a problem if you do it too quickly, use a tall and wide container. I simply used excess Barium Carbonate then filtered, boiled down and purified.

Toxicity is of course an issue with soluble Barium compounds, but normal "lab" hygiene is sufficient. If you are to later dispose of it react with a Sulfate to make Barium Sulfate which is essentially insoluble and relatively harmless. It can then be bagged and thrown out in the garbage; much better than simply tipping it down the sink!

Regards,

Alan

hey there mate, may i ask were you got your barium chloride from i am having a hard time trying to find it here in aus. thanks julian

Probably not, maybe as a cathode, but not likely to work as an anode.

Can an arc welding electrode with TiO coating in a chlorate cell?

thanks

Tom,

Not sure mate, it looks similar, but I have no way to tell if it is the exact same stuff. At least that site sells the anodes and cathodes separately.

Not too cheap though!

Regards,

Alan

Was the MMO you were using the same as the one shown here:

http://www.directpoolsupplies.com.au/prod646.htm

From the US, Skylighter mostly.

Just one more question, where did you actually source your Chlorine donors from? I don't really want to pay for shipping to Au. Have a good weekend.

I am not entirely convinced the addition of Chromate doesn't affect the anode, efficiency seems worse with it and it should be better. I tend to use Titanium cathodes anyway, so I don't really need it. I've read all the articles on its use commercially, but its just something else to remove during purification, and its somewhat toxic. I'm yet to try Fluorides in any meaningful way.

Keeping Chloride out of your Perchlorate cell and not running it too low in Chlorate concentration is the key to long anode life. i.e. Use fairly pure Sodium Chlorate as the feedstock for your Pt anode Perchlorate cells.

Potassium Chlorate isn't very soluble and Potassium Perchlorate is even less soluble. It isn't practical to make Potassium Perchlorate directly from Potassium Chloride if you want any kind of anode life.

5 Amps per litre is fine, but bear in mind that it will take at least a week at 5 amps to convert the 700 g or more of Sodium Chlorate you'll feed the cell with. (And probably about 4 weeks to make the Sodium Chlorate from Sodium Chloride at the same current, but use something other than the Pt anode for that if you can). An input of 400 g of Sodium Chloride will give you around 800 g of Sodium Perchlorate at the end of the process. You should get at least 700 g of Potassium Perchlorate out after purification with no extreme effort into getting everything out.

Thanks. Why shouldn't I use chromates? I am just worried about anode erosion as I spent almost all of my money on the setup and indicators. Is a current of around 5 amps in a solution of one litre acceptable? Does starting with potassium instead of sodium erode more?

The riser is Titanium, the same as the substrate, so it can be immersed. You can see the high-tide marks on mine where it has anodised.

You can measure the anode geometry and calculate its effective surface area. I just assumed about 20% of the planar anode area, which should be a reasonable figure.

I didn't use any additives at all. I was concerned about poisoning the anode. Don't use Chromates! I just kept the concentration of reactants up (most of the time anyway), to reduce wear on it.

Hey, just a quick question about those electrodes from palloys. Is the handle on them also Pt plated? I need to know whether I can immerse the whole thing or now. Also, have you done a surface area calculation for the 60 x 90 Pt anode? What additives did you use most of the time to protect them? Cheers

Jesse,

I dissolve the crystalline product in as little boiling water as possible (the tap water here is generally OK, but it depends on its mineral content, Calcium-rich water should be avoided). Start with a bit too much raw product to dissolve in the boiling water, then keep adding water to the boiling solution until all dissolves. Then the saturated solution is allowed to cool, slowly is best, as it forms large crystals which are easier to filter, especially for Potassium Perchlorate. The crystals are then filtered out with a coffee filter in a large funnel. The crystals are washed with ice-cold distilled water (or a saturated pure solution of the particular chemical in question if you prefer).

Several cycles are repeated until the product tests free of Sodium and Chloride. Sodium I test with a flame test, Chloride ions with Silver Nitrate solution. You can test the washings too, but I generally just wash with tap water for the first wash or two, using distilled water for the last washing.

I boil down the tailings, washing, etc and evaporate to dryness in a large pot. The solid waste gets stored and can be used to resaturate Sodium Chlorate cells if you want. You shouldn't wash it down the drain, but you can throw it out if you prefer to avoid the possibility of poisoning your anode with stray stuff accumulating in the waste.

Regards,

Alan

Could you please document your recrystallization process? Thanks

Indeed, I love that sound the bursting match pipe makes as it descends into the mortar followed rapidly by the lift thump. Can't forget the wonderful smell of black powder smoke too.

There is something very different about the sky-filling effects of fireworks. It stimulates your brain in ways that nothing else quite does. Its not just the "safe danger" effect, like roller coasters, something different. Something to do with varied colours and bright moving points of light spread across a large area of your visual field I think.

Of course, the sounds and smells are a big part too.

As you well know shooting a show is a lot of work for a fairly sort pyrogasm. Lots of lugging stuff around, bagging, dropping, tagging, foiling and wiring up. Then, the tear-down, in the dark after everyone else has gone home and you are already buggered from the setup, and usually in the damn rain! The high of the display helps a bit though.

G’day, there some nice picture you got there and a nice amount of (per)chlorate too well done.

I’m sort of in the same boat as you with the pyro licence thing though I haven’t got one yet, I’ve been working with a company for about 1 year now and I’ve noticed I've really slowed down on the home experiments. There’s nothing like hand lighting a rack of 4”er.

Mark,

Thanks. :)

I haven't tried a battery plate, but I have heard that it doesn't work. The plates of a modern battery are a lead grid pressed with oxide paste and various additives that will probably cause problems for a perchlorate cell.

You could try it, but I suspect the plate will rapidly fall apart, and the Sulfate and other stuff leaching out of it probably won't help the cell much. Best bet is a newly charged plate, preferably from a brand-new battery. Gel-cell plates are more fragile and likely to be exotic compared to truck or car batteries. The plates in batteries designed for deep-cycle use are more physically robust and should last longer (if such plates will work at all).

Regards,

Alan

Very impressive.

I understand that the cathode of a fully charged lead-acid battery should be PbO2 - would this do for a perchlorate cell anode? Small lead-acid batteries are available at reasonable cost from Jaycar.

Thanks for the inspiration, keep up the good work!

Mark :)

Not sure, but I doubt it. NiCr likely won't just passivate if there is any kind of defect in the plating, but having never tried it I can't tell you exactly what would happen.

Pt on Ti or Nb is the material of choice, as the base metal will anodise almost immediately and prevent further damage.

The I^2R losses (heating) of the NiCr also concerns me.

Nice. Would Pt plated Nichrome wire be good enough for perchlorate if I keep the ph in an acceptable range?

Cheers.

Thanks. :)

The chap calling himself "pkhow" on the UK Pyrotechnics Society Forums was kind enough to send me some samples of commercial anode material. He worked in the Pool Chlorinator business and was talking about making a commercial Chlorate cell product.

I haven't spoken to him since I gave up Chlorate production, so I am unsure where the venture got to. I doubt the market would support it, so it likely never happened. The material he offered was excellent, producing Chlorate almost indefinitely if not abused (and I produced a small amount of Perchlorate by abusing one piece, but it pretty much wrote it off).

Outstanding pictures and new web site. Glad to see you back with the updates. Where did you find the mmo electrodes for your experiments? They seem to be my missing link. I do now have a source for the platinium plated ones.

Rich