making potassium (per) chlorate

[MrB]

I'm sorry, i know this isn't "helpful" feedback, but here goes:

 

Great. Thanks. I cant spot anything wrong with it, looks good.

B!

[WSM]

I'm making little adjustments (refinements) to the blogs from time to time. I may even add material that wasn't included in the original articles. It may be a while before I add another one, due to the Holidays, travel and family or work demands.

 

I do have seven parts submitted, but have only seen five of them in print so far (PGI is saving a fortune in postal costs by using bulk mailing, but the delivery times are dismal).

 

WSM

[MrB]

Wait... What? Your letting LIFE get in the way of a hobby? Mine, that is. No. I demand a full refu... Oh.

 

Dude, just know we are waiting on edge for the rest of the articles. But take your time, don't burn out, make sure to spend quality time with loved ones.

We can wait. Or at least i can. I got the next couple of years worth of perchlorate stashed already. I just love to read about your efforts.

B!

[Arthur]

Just finished reading an old article about a perc factory in Nevada. They made sodium chlorate at 600g/l then ran it slowly through a cell to become 100g/l chlorate and the rest NaPerc then they made the K salt or the NH4 salt as wanted in the rocket industry. Lots of huge platinum anodes but the cell was steel and was the cathode. Lots of cells wired in series accounting for 5000A at about 6v per cell.

 

Whether this was the "Pepcon" factory I don't know, there were two perc factories close to each other in Nevada.

[WSM]

Just finished reading an old article about a perc factory in Nevada. They made sodium chlorate at 600g/l then ran it slowly through a cell to become 100g/l chlorate and the rest NaPerc then they made the K salt or the NH4 salt as wanted in the rocket industry. Lots of huge platinum anodes but the cell was steel and was the cathode. Lots of cells wired in series accounting for 5000A at about 6v per cell.

Whether this was the "Pepcon" factory I don't know, there were two perc factories close to each other in Nevada.

 

Can you post the article here so we can read it? It sounds like an informative read...

 

WSM

Edited December 2, 2014 by WSM

[pyrojig]

Yes please do post information on the factory methods . Also I am pleased to hear your making progress on the articles as well. It is nice to see the industry way of doing things v.s. the amateur approach . I think there is much area for new innovations and research. With all the creative minds at work on our forum I believe that we can push into new territory and maybe change the way of perch production ,. Indeed this is the "golden egg " most all pyros are after. It would be a perk if the cost was kept reasonably close to industrys ...But that is a pie in the sky dream at the moment .

[MrB]

Well, if the cell can be stainless steel, then i just need to find out what grade, and ask a mate to make me one. So that alone peaked my interest. There is good, and bad to this of course. There is no way we / i can afford to run "huge platinum anodes", and the steel will transfer the heat quite well, so to get the process temp up to where we want it, one might want to insulate parts of it... And, i suppose the anodes will have to be quite close to the walls to make it produce at all, at our voltages.

B!

[WSM]

Well, if the cell can be stainless steel, then i just need to find out what grade, and ask a mate to make me one. So that alone peaked my interest. There is good, and bad to this of course. There is no way we / i can afford to run "huge platinum anodes", and the steel will transfer the heat quite well, so to get the process temp up to where we want it, one might want to insulate parts of it... And, i suppose the anodes will have to be quite close to the walls to make it produce at all, at our voltages.

B!

 

Long ago I thought of using stainless steel for a cell but abandoned the idea in favor of compatible plastics or glass. In fact, stainless or even regular steel will work due to cathodic protection if connected to the negative lead of the power supply. The grade of stainless doesn't matter in this case, though if I were to try it, I'd prefer 316 as it's highly corrosion resistant.

 

There is no need to heat the cell because, due to internal cell resistance, it'll heat itself. Industry usually controls the cell temperature by running cool water through hollow electrodes to keep things from getting too hot.

 

The spacing between anodes and cathodes can be very close (say 3mm or 1/8") or further apart, depending on your preferences. Closer works, but be sure to maintain the gap while it's runing or the electrodes may touch each other and likely damage your power supply. It seems easier to keep the electrodes from shorting out the power supply if the gap between them is a little further apart.

 

Remember the electrolyte is somewhat conductive. The voltage (electromotive force or "pressure", if you will) pushes the cell reactions but the current or amperage (consider it the "volume" of electrons) does most of the work.

 

The highest efficiency chlorate cells depend more on pH than the electrode gap. If the power to the cell is right and the pH is at the best level, we encourage what is known as a "bulk reaction" where our chlorate ions are produced throughout the cell simultaneously, not just between the electrodes.

 

The overall function of this whole system is highly complex, but we describe it in simple terms to help each other keep focus on what's required get the final product (chlorate and/or perchlorate).

 

WSM

Edited December 2, 2014 by WSM

[MrB]

 

Long ago I thought of using stainless steel for a cell but abandoned the idea in favor of compatible plastics or glass. In fact, stainless or even regular steel will work due to cathodic protection if connected to the negative lead of the power supply. The grade of stainless doesn't matter in this case, though if I were to try it, I'd prefer 316 as it's highly corrosion resistant.

I was thinking some grades would be better then others, since your going to have to turn the darn thing of at some point. 316 is a good grade, since they do a lot of 316 / 430 work and have plenty of "scraps".

 

There is no need to heat the cell because, due to internal cell resistance, it'll heat itself. Industry usually controls the cell temperature by running cool water through hollow electrodes to keep things from getting too hot.

Considering that the industry runs quite a bit more current through the system then we do, they pretty much have to keep it from boiling. I was more thinking along the lines of our systems. Where plastic buckets, and glass jars run fine, the heat transfer of a stainless container might be to good, and cause the temperature to drop "to" low. Your probably more informed, but i think i read 40c or something for lead dioxide (per)chlorate cells. Regardless of what the temperature goal is, the reaction is generating heat. If the cell can dissipate it faster then it generates it, then the heat remains low, if not, the temp starts climbing until the generated heat, and the dissipation capacity is equal. Since it's easier to insulate the cell, then to heat up the room... ;- )

 

The spacing between anodes and cathodes can be very close (say 3mm or 1/8") or further apart, depending on your preferences. Closer works, but be sure to maintain the gap while it's runing or the electrodes may touch each other and likely damage your power supply. It seems easier to keep the electrodes from shorting out the power supply if the gap between them is a little further apart.

Closer means more current will pass, further means less, for any given system. To some extent i'm sure you can play around with the variables, as you say, we much rather not short the cell out, and wake up in the morning, just to find the fireman standing next to your bed, telling you that they had to drive the fire engine through your house to get to the burning outhouse out back... While he might be a she, and cute as a button, that time in the morning is my "me" time, and i'd much rather be alone, or just with the person who i fell asleep with.

B!

[Arthur]

Crystallization of Ammonium-Perchlorate from Solution of

Electrolytically Produced Sodium-Perchlorate in a Pilot-

Scale Plant

Pages 45-53.

Trans. Electrochem. Soc. 1947, Volume 92, Issue 1,

Joseph C. Schumacher

Perchlorates

 

Joseph C. Schumacher

The Commercial Production of Perchlorates

Are useful google phrases to search for. The docs are too big to PM. Careful searching brings up a lot of info, but the first two facts seem to be- start with sodium salts and do perc with platinum.

[WSM]

Closer means more current will pass, further means less, for any given system.

 

Closer means more current will do productive work and less is used to heat the cell (as when further away). Heat isn't wasted in a chlorate cell, but it doesn't produce the chlorate; It just helps things along.

 

WSM

[WSM]

Crystallization of Ammonium-Perchlorate from Solution of

Electrolytically Produced Sodium-Perchlorate in a Pilot-

Scale Plant

Pages 45-53.

Trans. Electrochem. Soc. 1947, Volume 92, Issue 1,

Joseph C. Schumacher

Perchlorates

Joseph C. Schumacher

The Commercial Production of Perchlorates

Are useful google phrases to search for. The docs are too big to PM. Careful searching brings up a lot of info, but the first two facts seem to be- start with sodium salts and do perc with platinum.

 

Ah, yes; found them. Thanks, Arthur.

 

I'll try to read them more carefully when life gets a little less hectic.

 

WSM

Edited December 5, 2014 by WSM

[Arthur]

Lots of the critical numbers are in Schumacher's papers, BUT his idea of electrode current is 5000amps I'd be satisfied with 5A continuous. His factory used platinum sheet 6thou thick

[Arthur]

Some preliminary figures, a 4a Pt electrode would cost £200 and a 15a electrode would be £520 just for the platinum, according to the metal spot prices.

[WSM]

Lots of the critical numbers are in Schumacher's papers, BUT his idea of electrode current is 5000amps I'd be satisfied with 5A continuous. His factory used platinum sheet 6thou thick

If that 0.006" platinum sheet were solidly clad on titanium, I imagine it would make a heavy duty anode.

 

WSM

 

Edit: In fact, if the anode were a solid titanium sheet with only 0.003" of platinum cladding on both sides, I'd be thrilled.

Edited December 7, 2014 by WSM

[WSM]

Some preliminary figures, a 4a Pt electrode would cost £200 and a 15a electrode would be £520 just for the platinum, according to the metal spot prices.

Numbers like that make lead dioxide look a LOT more attractive!

 

WSM

Edited December 7, 2014 by WSM

[MrB]

Numbers like that make lead dioxide look a LOT more attractive!

As if it wasn't the most attractive thing already. A shame that they aren't freely available.

B!

[WSM]

As if it wasn't the most attractive thing already. A shame that they aren't freely available.

B!

 

True. The last time I saw some at a decent price, I negotiated for a better per unit cost and bought four of them.

 

I still need to test them but I have hopes they'll work out and produce lots of sodium perchlorate which can be converted to other useful perchlorates. We'll see...

 

WSM

[pyrojig]

Whatcha think about a bucket cell being adapted for the use in perch production as a cheap cell? Is there really any reason to change the cell size ,shape ,or structure to go to perch production on a amateur scale . ??? I really have been pondering starting the perch process myself. Maybe running two bucket cells at a time , one with mmo to produce NaClo3 , and another to Produce NaClo4 .Or just having (2) BCA lids with diff electrodes With this one may be able to " Flip batches" and have a one roll right into the next

[Arthur]

Crystallization of Ammonium-Perchlorate from Solution of Electrolytically Produced Sodium-Perchlorate in a Pilot-Scale Plant

is a search phrase for a learned paper discussing both chlorate and perchlorate production, with the chemistry and chemical engineering described.

They use two cells one for chlorate and the other to progress to perc.

Currently what we NEED is a single fully functioning process somewhere producing perc, afaik there isn't one yet. Then we can discuss the finer points of electrodes. Yes I think there is much to be learned from progress in electrochemistry maybe lead dioxide is what the Chinese use. (and my bag of perc says things in Spanish on the outside but says things in Cantonese on the inner wrapper -it's overbagged Chinese perc anyway)

Does anyone have good things to say about the Chinese Lead dioxide electrodes.

Platinum simply works, remember that a sheet of Pt hanging in solution has two sides but Pt clad only has one side.

From the paper by Schumacher we know that Pt is the industry standard (or it was in the 50s)

[MrB]

I want to use lead dioxide anodes to go from KCl to KClO4. It might not be "as efficient" but it's a lot more user friendly, if you can set it up, and run it until you got your end product, rather then scavenging the system, filtering the chlorate, and "starting over" to run the perchlorate cell.

 

If it's at all going to be reliable, not sure. It's "supposed" to work, but... Anyway, i'm nowhere near that spot. I still need to buy a house and move first. Been looking for the right one for a couple of years.

B!

[Arthur]

Two cells allows us to use Pt only where it is essential which is cheaper

[Arthur]

The issue with Pt electrodes is simply cost. It's available by post you just have to pay for it. The issue with Lead Dioxide is toxicity, you will have disposal issues with the plating solution and the electrodes, and may have lead in the final product.

 

If anyone is familiar with electroplating chemistry then perhaps we could find a good method of producing a run of lead dioxide electrodes and dealing with the waste.

[WSM]

From the paper by Schumacher we know that Pt is the industry standard (or it was in the 50s)

 

Of course, at that time graphite was the industry standard for chlorate. We've come a long way since then...

 

WSM

[WSM]

I want to use lead dioxide anodes to go from KCl to KClO4. It might not be "as efficient" but it's a lot more user friendly, if you can set it up, and run it until you got your end product, rather then scavenging the system, filtering the chlorate, and "starting over" to run the perchlorate cell.

 

I have an article buried away somewhere, describing such a system (well, a small pilot plant, actually) which did, in fact, produce sodium perchlorate directly from sodium chloride. It was done by researchers in India but the article was published in english.

 

A couple points regarding the system that keep me from trying it are these:

1. They include sodium fluoride in the process, which destroys titanium, but is critical to the success of their system.
2. They made their own beefy anodes which were beta-form lead dioxide on graphite.

All of my lead dioxide anodes are formed on titanium substrates, so the use of NaF is out. I'm not yet set up to make my own LD anodes, or I might give their system a try.

 

Logistically, it just makes more sense for me to do it in two steps; first make good quality sodium chlorate, then make good quality (chlorate free) sodium perchlorate, before going on to other perchlorates. I'm closer to doing it this way, than by other methods at this point in time.

 

WSM