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making potassium (per) chlorate


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#4741 WSM

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Posted 20 August 2017 - 03:04 AM

A while ago I made a note of something Swede had posted about the rate of acid dosing. Adding 0.057 mL of 32% HCl per amp per hour with the HCl volume cut by 33% after crystals form seemed to be the ideal rate for him. Is this a good rule of thumb to go by? It's those numbers that also led to my believing that I wasn't adding enough HCl to my chlorate cell. I'm also wondering now, how susceptible is this rate to the cell temperature?

 

I believe it is, and a good starting point. Remember, if you dilute the acid, increase the volume by that same amount.

 

If you drop the acid to an 8% solution (1/4 of full concentration), multiply the volume by 4 and see if that works for you.

 

WSM B)


Edited by WSM, 26 August 2017 - 07:56 AM.


#4742 Arthur

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Posted 20 August 2017 - 09:46 AM

In the HOT chlorate cell process the acid is added to the chloride solution added to keep the volume constant, by dip tube to the bottom of the cell.



#4743 PTFE

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Posted 21 August 2017 - 03:59 AM

Okay I will put one on order when I get paid and we will see where I am at when it is connected...
Thanks again WSM

hey guys.. after a little Break I'm back with an other run of a quick and dirty 10l Cell@125A.

Pictures will come thursday or friday when everything is finished :)

 

Since my last visit many things where written here, so i give them a read in the next time.

 

now, to give you some help with your current-meter if its not too late:

The Values for the shunt and the decimal place are normally set by jumpers and/or Potentiometers beneath the cover of the front, so you might take a look.

 

 

greetings, PTFE

 

edit1

 

Did you get any salt creep coming through in between the boro. glass and the PTFE tubing?

 

 

Hey kevin. Sorry for my late response.

I never had any salt creep around the tube.

Also you have to fill the tube up with water, to get a better Heat conductivity, this will stop any electrolyte or Salt crystals from entering your sensortube.


Edited by PTFE, 21 August 2017 - 04:29 AM.


#4744 WSM

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Posted 26 August 2017 - 08:37 AM

Some kind of titanium compound makes sense. I gave my anode a hydrochloric acid soak last year after mounting it to the titanium tubing- turned the acid a yellow color from dissolved iron, I believe. Might have to give the cathodes a soak.
I have a tube in the shape of the letter J with several small holes in the end. I used this shape because when my initial run was completed, a few days after I stopped adding acid, I noticed that the fluid level inside the tubing was well above the holes, meaning acid was still seeping into the cell.
I do believe you are correct, WSM, that my acid dosing rate is too high. Less K-chlorate seems to be forming at the bottom than I'd expect at this point and, after increasing the acid rate yesterday, there may be even less present today. I should add that my cell temperature is maintained at 60C, within about 0.3C by means of an internal temperature sensor controlling an external fan, so I've ruled out temperature increase as the cause of my crystals' disappearance.
The thing that's confusing me the most, however, is the apparent lack of change of the pH. When dosing the acid- even at a very low rate- the pH seems to settle at around 6. If I cut the rate in half, it's the same and if I stop adding acid altogether it looks to be about the same- even after a few days.. I must be reading my pH papers wrong or maybe they aren't very good. I got them this past Winter from ebay. When I dip them in the solution, the bottom part of the paper is bleached pretty much instantly, so I look above, where it has soaked up the paper a little bit and compare its color to the colors on the pH paper packaging.

 

Those who use pH control (HCl acid injections to lower the alkalinity) have reported that the amount of acid required diminishes as the cell runs. The pH tends to reach something of an equilibrium where further acid doses either aren't needed or the amount is greatly reduced.

 

Swede said something about dropping the acid injections to 2/3 the starting amounts when KClO3 crystals start to form. Since everyone's cell is different, I would suggest we use his recommendations as a starting point only, and fine tune our cell from there. Realize that the chlor-alkali cell is a complex and dynamic environment, with all the components in a state of constant flux.

 

This is what we want; we take a stable salt solution, add current and drive the reaction to build desired compounds. Lots of changes happen in the solution as we do so, all at the same time, and the complexity of it is the subject of Doctoral dissertations. The exact chemistry of what is in our cells at any given moment is highly dependent upon where in the process we are and for how long it has run (plus myriad other variables). 

 

Optimizing our cell for the highest efficiency is tricky business, and adding acid with a light hand plus careful monitoring is called for. Even then, the cell's requirements change as it goes, so no hard, fast rules will do the job, but we need to watch it carefully and respond appropriately according to the changes we observe.

 

All this is not easy, but it is worth it; especially if you are scaling up the scope of your operation.

 

WSM B)


Edited by WSM, 28 August 2017 - 05:33 AM.


#4745 Kevin

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Posted 27 August 2017 - 11:15 PM

 

Those who use pH control (HCl acid injections to lower the alkalinity) have reported that the amount of acid required diminishes as the cell runs. The pH tends to reach something of an equilibrium where further acid doses either aren't needed or the amount is greatly reduced.

 

Swede said something about dropping the acid injections to 2/3 the starting amounts when KClO3 crystals start to form. Since everyone's cell is different, I would suggest we use his recommendations as a starting point only, and fine tune our cell from there. Realize that the chlor-alkali cell is a complex and dynamic environment, with all the components in a state of constant flux.

 

This is what we want; we take a stable salt solution, add current and drive the reaction to build desired compounds. Lots of changes happen in the solution as we do so, all at the same time, and the complexity of it is the subject of Doctoral dissertations. The exact chemistry of what is in our cells at any given moment is highly dependent upon where in the process we are and for how long it has run (plus myriad other variables). 

 

Optimizing our cell for the highest efficiency is tricky business, and adding acid with a light hand with careful monitoring is called for. Even then, the cell's requirements change as it goes, so no hard, fast rules will do the job, but we need to watch it carefully and respond appropriately according to the changes we observe.

 

All this is not easy, but it is worth it; especially if you are scaling up the scope of your operation.

 

WSM B)

 

I think this is the explanation I've been looking for to solve the mystery as to why my pH doesn't seem to increase. In my last few trials I've added too much HCl and brought the pH too low, leading me to stop all acid additions in efforts to increase it. However, even after several days my pH barely gets about 6.

 

I diluted my HCl to 10% for my latest K-chlorate run but it appears my pH is too low once again. It's tricky to get it just right! I didn't get the acid additions started until about a day and a half after the run began.I believe this resulted in an even greater acid demand initially, which would likely have decreased very rapidly upon reaching 6.7- 6.8.

 

I'm also running into a new problem now: It seems that after beginning to regulate my cell's temperature, the crystals at the bottom form a nearly solid mass. After my last run, I had to break the chlorate crystals into a couple large pieces with a plastic rod and a hammer to be able to remove them. Any suggestions as to how to avoid this? I'm thinking of insulating the lower portion of my cell to see if it helps any. 

 

With regards to my earlier comments about the cell electrolyte' smell: after some research I found that hypochlorite decomposes naturally to produce primarily salt and oxygen. However, when the pH is acidic, chlorine gas is also formed, which would explain the smell- and its persistence- of my electrolyte.

 

 

In the HOT chlorate cell process the acid is added to the chloride solution added to keep the volume constant, by dip tube to the bottom of the cell.

 

This is the ideal I'm hoping for- once I get my cell figured out. That said, I'm hoping to scale up and switch to sodium chlorate in the future for the purpose of making potassium perc, which means a whole new system to figure out- I think I opened Pandora's box when I got into this!

 

Thanks again for all the help,

 

Kevin



#4746 WSM

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Posted 28 August 2017 - 05:49 AM

I think I opened Pandora's box when I got into this!

 

I SO understand, and yet; isn't it a fascinating journey?!!

 

The further I get into this pursuit, the more I learn and am able to do. Many interesting insights and a lot of understanding has come my way during this process. The problem is, no one lives long enough to make all the mistakes themselves; therefore THANKS to all who've shared their electrochemical trials and experiences, with the group.

 

WSM B)


Edited by WSM, 28 August 2017 - 05:55 AM.


#4747 WSM

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Posted 02 September 2017 - 08:47 AM

A couple days ago I was shopping at a home furnishings store with my Wife and found a treasure. They were having a sale and clearing out last year's display models at incredibly low prices, so I picked up a huge glass vase that resembles a battery jar from the old days:

 

Attached File  IMGP8077.JPG   132.91KB   1 downloads  Attached File  IMGP8079.JPG   94.88KB   0 downloads

 

This thing has a capacity of about 25 liters and is 58 cm tall (inside), has an inside diameter of 23.5 cm and the wall thickness is 7 mm.

 

Imagine what I think I can use it for?!! :lol:

 

If it works, wonderful; and if it doesn't, I'm only out $10 (plus the time invested in the project).

 

If you're living right (and keep your eyes open) things seem to work out.

 

WSM B)


Edited by WSM, 03 September 2017 - 08:25 AM.


#4748 PTFE

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Posted 29 September 2017 - 10:01 AM

Attached File  Electrolysis.JPG   101.45KB   7 downloads

 

New cell is in construction :)



#4749 WSM

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Posted 29 September 2017 - 10:38 AM

attachicon.gifElectrolysis.JPG
 
New cell is in construction :)

 
Excellent! Can you share any details?

WSM B)

Edit: That's odd. I didn't see the drawing till I posted my uninformed response. That's the downside of using the "smartphone" to view posts on APC (darned tiny screen :( )

Edited by WSM, 03 October 2017 - 03:02 PM.


#4750 WSM

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Posted 03 October 2017 - 03:10 PM

I've decided to write the next part (Part 17) of the series, Homegrown Oxidizers, on the purification of raw materials as well as all the materials involved in every aspect of the process of creating our own oxidizers.

I plan to get back to the high temperature sodium chlorate experiment later, but for now it's on hold due to my very busy work schedule and home life.

I've got much more to share about purity and purification of the materials we use in preparing our pyrotechnic chemicals.

To be continued...

WSM B)


Edited by WSM, 08 October 2017 - 08:20 PM.


#4751 pyrojig

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Posted 07 October 2017 - 09:58 PM

excited to read it when your done .!! I too have suffered a overly heavy work load and feel bad I have not been able to contribute to the thread in a very long time . I miss the innovative minds at work here  . I should be slowing down this winter a bit , and may be able to chime in on some experience or questions .   WSM , please do keep me updated on the next additions your writing . I would like to add it to the collection as well as see your latest work. 



#4752 WSM

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Posted 08 October 2017 - 09:23 PM

I've started a purification experiment with potassium chloride. I want to see if purifying the KCl (water softener salt) works as well as it did with the sodium chloride salt used to make brine for the sodium cell experiment.

 

I used the second large brine tank and put in a 50 pound container-full (plus a bit more) of KCl water softener salt, and then added 12 gallons of distilled water (it needed 17 gallons but twelve was all I had on hand) and started the circulation pump about 7 PM two days ago. 

 

The goals of this experiment are:

  1. dissolve the KCl salt to roughly 350 grams per liter of pure water
  2. filter out any insolubles or solid debris  
  3. treat the clear filtrate with potassium carbonate solution to precipitate any dissolved contaminates
  4. let the cloudiness settle and then decant the clear liquid, plus filter out the precipitate
  5. test the pH of the filtrate and if it's alkaline (as expected), neutralize it with HCl
  6. store the purified KCl brine in a sealed container for later use

The purified potassium chloride brine can either be electrolyzed to potassium chlorate or used to react with other pure salt solutions to make pure potassium salts.

 

WSM B)


Edited by WSM, 14 October 2017 - 07:43 AM.

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#4753 WSM

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Posted 31 October 2017 - 07:35 AM

I was tired of looking at undissolved crystals on the bottom of the brine tank, so I bought and added six more gallons of distilled water.

A few days later all the crystals were dissolved and I could clearly see the debris on the bottom of the tank.

The next step is to filter the course contaminants out before treating the clear solution to remove unseen contaminants.

I'll post more later.

WSM B)

#4754 WSM

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Posted 02 November 2017 - 06:52 AM

I should mention that my original calculation was for 17 gallons of water in 50 pounds of KCl to make up a stock solution of potassium chloride (350g/l), but since I added more KCl, the extra gallon was needed. I'll try to take more photos so you can see what I'm seeing. 

 

More later...

 

WSM B)



#4755 WSM

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Posted 17 November 2017 - 06:35 AM

I just submitted Homegrown Oxidizers Part 17 to the PGI for printing in their December-January bulletin. The subject varies from making oxidizers to purification of precursor, process and final product chemicals. 

 

I feel the subject is important enough to dedicate an article or two to it. We may be happy just to be able to make our own oxidizers, but since we're going to the trouble to do so, why not make the effort to make them as pure as (or even purer than) commercial oxidizer salts?

 

I hope to cover this topic better in the future; maybe even start a separate thread covering purification of chemicals. It would greatly increase safety for amateurs, as well as offer an improvement to color depth and clarity of stars, too.

 

Any thoughts?

 

WSM B)


Edited by WSM, 18 November 2017 - 07:49 AM.





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