making potassium (per) chlorate

[WSM]

Will the current drop noticeably when the chlorate level gets low enough to harvest the perchlorate?

 

 

I didn't notice the current drop since I used a power supply with CC (constant current) mode, BUT I did notice a slight change in the Voltage, and that was a clue to the cell nearing the end of the run.

 

WSM

 

Edit: By the way, I ran my two perchlorate experiments at low current, to avoid harsh treatment of the anodes, at between 1.0 to 2.0 Amps per centimeter squared.

 

They worked well, AND, don't be alarmed by the ozone generated and evident at the vent of the cell! I believe it's all normal.

Edited March 4, 2020 by WSM

[PTFE]

hey.

Its quite a while ago and the EPDM stopper arrived and got destroyed the same day it was drilled and used.

I have orderd some natural corc stoppers for my little 150ml experiment

One thing i want to share. If you use universal indicator paper it is best used by dipping a glass rod into the liquid and put that rod with some elektrolyte left onto the PH-paper. You will get a good measurement and the bleaching is not immediately.

[WSM]

hey.

Its quite a while ago and the EPDM stopper arrived and got destroyed the same day it was drilled and used.

I have orderd some natural corc stoppers for my little 150ml experiment

One thing i want to share. If you use universal indicator paper it is best used by dipping a glass rod into the liquid and put that rod with some elektrolyte left onto the PH-paper. You will get a good measurement and the bleaching is not immediately.

 

Hey PTFE,

That's a good tip about applying a drop of electrolyte to the test strip.

 

If or when I use that technique, I'll credit you with it.

 

Good luck with the tiny cell.

 

WSM

[PTFE]

Hey PTFE,

That's a good tip about applying a drop of electrolyte to the test strip.

 

If or when I use that technique, I'll credit you with it.

 

Good luck with the tiny cell.

 

WSM

Thank you, WSM!

You dont have to credit me for this tip but thanks a lot! I think it's the common way of measuring with ph-strips in a lab.

Imagining an difficult and costly reaction the Strip could add some unwanted ions or molecules or the indicator itself to the reacion mixture, maybe ruining a whole experiment.

 

 

The small cell is running again to see, if perchlorates are possible without damaging my anode.(maybe the high temperature is causing the formation of the perchlorate)

 

But its mostly because of the fun i have, when a cell is running.

 

the old epdm Sh*t ( I think it would have been a nice stoper if I had the rigth tools or technique for drilling the holes.)

 

and the new cork which is so much nicer ♥

 

 

 

A good day to everyone and have a nice weekend!

 

PTFE

[Pyrophury]

I took a 20ml sample of electrolyte from my cell, added 35ml KCl solution (6g KCl) and tested the precipitant for the presence of chlorate/perchlorate.

 

 

Top left is a sample of the ppt I harvested from the cell by freezing before I started my perc run (NaClO3), next to it and below is a sample of the ppt I just took from my cell after adding KCl solution, to which I then added a few drops of conc. HCl (top) and methylene blue (bottom).

 

It looks to show a weak reaction for the presence of chlorate and strong indication for perchlorate.

 

Tomorrow I will stop the run, attempt to neutralise the electrolyte in small batches and react the rest with KCl, filter and wash the precipitant.

[WSM]

I took a 20ml sample of electrolyte from my cell, added 35ml KCl solution (6g KCl) and tested the precipitant for the presence of chlorate/perchlorate.

Top left is a sample of the ppt I harvested from the cell by freezing before I started my perc run (NaClO3), next to it and below is a sample of the ppt I just took from my cell after adding KCl solution, to which I then added a few drops of conc. HCl (top) and methylene blue (bottom).

It looks to show a weak reaction for the presence of chlorate and strong indication for perchlorate.

Tomorrow I will stop the run, attempt to neutralise the electrolyte in small batches and react the rest with KCl, filter and wash the precipitant.

 

 

Nice! Looks like fun.

 

I look forward to having some fun, too.

 

WSM

Edited March 6, 2020 by WSM

[Andead]

For making sodium perchlorate what is the maximum and minimum voltage required and if so what rails do you use from the atx power supply because by using the 12volt rail the voltage is from 7 to 8 and i dont want to excessively damage my new lead dioxide electrodes...

[Andead]

 

This is the first time i have tried to obtain sodium chlorate for me to know my starting amount of chlorate for perchlorate synthesis, is all the white salt that has precipitated out sodium chlorate or sodium chloride cause i just cant believe that that much sodium chlorate is present in 1 litre of solution.

[WSM]

For making sodium perchlorate what is the maximum and minimum voltage required and if so what rails do you use from the atx power supply because by using the 12volt rail the voltage is from 7 to 8 and i dont want to excessively damage my new lead dioxide electrodes...

 

 

I ran my perchlorate experiments at about 4 Vdc, and current at about 0.1-0.2 Amps per square centimeter. I also used a small laboratory power supply on CC (constant current) mode, so the current stayed the same but the voltage varied as the demand changed.

 

I ran my experiments on low power to preserve the anodes. Other experimenters were reporting destruction of their Chinese made LD anodes, and my best guess was that they were running them the same way they ran their MMO chlorate cells. This was over-powering their lead dioxide anode and likely causing the damage they reported, I supposed.

 

I recommend going easy on your LD anode till you get a feeling for how it works. Please don't use it for chlorates; MMO does a much better job for that. Save the expensive and hard to source LD or platinum anodes for perchlorate cells.

 

WSM

[WSM]

 

This is the first time i have tried to obtain sodium chlorate for me to know my starting amount of chlorate for perchlorate synthesis, is all the white salt that has precipitated out sodium chlorate or sodium chloride cause i just cant believe that that much sodium chlorate is present in 1 litre of solution.

 

I'm not certain, but the material in those containers look like wet chloride.

 

My first sodium chlorate cell was run on a larger scale (>20 liters capacity), and ran for 6 weeks at the voltage and current demanded by the size of electrodes I used. After I removed the electrolyte liquid from the cell (sodium chlorate doesn't drop out of solution unless the concentration is high enough to do so; often by boiling off the water), I put the electrolyte (3 liters at a time) in a refrigerator running at about 0^oC, for a day or two. I managed to collect roughly a third to half of the dissolved sodium chlorate as crystals in the bottom of the container. The rest of the dissolved sodium chlorate remains in the "spent" electrolyte, waiting to be recharged with brine and run in the cell again. The subsequent runs should produce chlorate faster, since the precursors (hypochlorite and hypochlorous ions) are already in solution and aren't made from scratch like the in the first run.

 

 

You may want to invest in a chlorate test kit. There are several different tests for chlorate, and though some of the reagents are expensive and/or difficult to find, they are worth the effort to obtain them.

 

One problem with all of them is that the prepared test solution's viability is short-lived; they don't keep well once mixed. The best fix is to prepare only small amounts of test solution and use it quickly, or better yet, create a spot test using only the smallest amount of the reagent per test, as you can. This way you can economize your testing of chlorates.

 

Once you know for certain what (and how much) material you have in your cell, you can determine your following course of action.

 

WSM

Edited March 9, 2020 by WSM

[Andead]

 

 

I'm not certain, but the material in those containers look like wet chloride.

 

My first sodium chlorate cell was run on a larger scale (>20 liters capacity), and ran for 6 weeks at the voltage and current demanded by the size of electrodes I used. After I removed the electrolyte liquid from the cell (sodium chlorate doesn't drop out of solution unless the concentration is high enough to do so; often by boiling off the water), I put the electrolyte (3 liters at a time) in a refrigerator running at about 0^oC, for a day or two. I managed to collect roughly a third to half of the dissolved sodium chlorate as crystals in the bottom of the container. The rest of the dissolved sodium chlorate remains in the "spent" electrolyte, waiting to recharged with brine and run in the cell again. The subsequent runs should produce chlorate faster, since the precursors (hypochlorite and hypochlorous ions) are already in solution and aren't made from scratch like the in the first run.

 

 

You may want to invest in a chlorate test kit. There are several different tests for chlorate, and though some of the reagents are expensive and/or difficult to find, they are worth the effort to obtain them.

 

One problem with all of them is that the prepared test solution's viability is short-lived; they don't keep well once mixed. The best fix is to prepare only small amounts of test solution and use it quickly, or better yet, create a spot test using only the smallest amount of the reagent per test, as you can. This way you can economize your testing of chlorates.

 

Once you know for certain what (and how much) material you have in your cell, you can determine your following course of action.

 

WSM

Thanks so much WSM, you are helpful as always.

[Pyrophury]

I ended the run and after removing the electrodes and allowing the electrolyte to settle, it was apparent that a brown sediment had coated the sides and bottom of the RC. It was only a thin coating however and came off easily. The electrolyte itself was crystal clear with a blueish tint.

 

 

The anode looks good, no obvious signs of wear but it has turned black whereas before it was a lighter grey. The cathode has been completely coated in a layer of grey powder which comes off easily. Is this lead (Pb)?

 

 

I neutralised a 500ml sample of the electrolye with dilute HCl and boiled it, before adding 500ml hot saturated solution of KCl (140g). This was allowed to cool while crystals precipitated, then vaccuum filtered and washed twice with 500ml ice cold deionised water. The washed Ppt was then dried on a hot plate.

 

 

 

The yield from this 500ml sample of electrolyte was 200g, I have around 3L of electrolyte still to process.

[markx]

Excellent results! Seems that the commercial LD anode has held up quite nicely and the small tinge of brown is probably originating from the topmost layer that had unstable formations which eroded off exposing a more durable dense layer. The next conversion run should be cleaner and have less, if any brown residue forming at all. If it still does form then it likely indicates that the LD is still slowly eroding.....but this is a better outcome that I've been able to achieve with any of my diy LD attempts.

 

The greyish residue on cathode is more likely a type of carbonate/hydroxide mix that forms from contaminants and to some degree from exposed Ti. I also see this kind of deposit in my Pt based setup. After drying it becomes almost white and in my case it also tends to deposit on the Pt anode. Scrubbing and acid wash usually makes short work of it.

[WSM]

Excellent results! Seems that the commercial LD anode has held up quite nicely and the small tinge of brown is probably originating from the topmost layer that had unstable formations which eroded off exposing a more durable dense layer. The next conversion run should be cleaner and have less, if any brown residue forming at all. If it still does form then it likely indicates that the LD is still slowly eroding.....but this is a better outcome that I've been able to achieve with any of my diy LD attempts.

The greyish residue on cathode is more likely a type of carbonate/hydroxide mix that forms from contaminants and to some degree from exposed Ti. I also see this kind of deposit in my Pt based setup. After drying it becomes almost white and in my case it also tends to deposit on the Pt anode. Scrubbing and acid wash usually makes short work of it.

I've also noticed the coating on the cathode during my experiments, and wondered what it was. I expected the cathode would remain clean due to "cathodic protection", but not in this case, apparently.

 

You expressed the opinion that it's carbonate or hydroxide, but I'm wondering if it's titanium dioxide?!

 

A test could/should be done to answer the question.

 

WSM

Edited March 10, 2020 by WSM

[markx]

I've also noticed the coating on the cathode during my experiments, and wondered what it was. I expected the cathode would remain clean due to "cathodic protection", but not in this case, apparently.

 

You expressed the opinion that it's carbonate or hydroxide, but I'm wondering if it's titanium dioxide?!

 

A test could/should be done to answer the question.

 

WSM

Now that you mention it is actually quite likely that part of the deposit may originate from titanium of the cathodic side of the cell. I've observed very little wear on the Ti parts of the anodic halfcell, but my cathode plates bear visible scars after prolonged use. There are stains and structures that resemble minor pitting. These can not be removed unless abrasive approached are practiced. So it is possible that sidereactions involving dissolution of the cathode are taking place. In fact it makes sense as Ti is a very active metal from a chemical point of view. The apparent inertness of Ti is only due to the imprevious oxide coat that shields the metal from outside influences. The same can be said for aluminum.e.g. This oxide coat is weakened under cathodic potential exposing the substrate metal to the agressive electrolyte.

 

As a matter of fact there exist electrochemical methods to alter said oxide coating under cathodic potential and rendering it into a structure that remains conductive also under anodic potential. In other words it is possible to make a Ti substrate TiO2 anode:

 

https://www.sciencedirect.com/science/article/pii/S0013468614014546

 

kim2014.pdf

[WSM]

As a matter of fact there exist electrochemical methods to alter said oxide coating under cathodic potential and rendering it into a structure that remains conductive also under anodic potential. In other words it is possible to make a Ti substrate TiO2 anode:

https://www.sciencedirect.com/science/article/pii/S0013468614014546

kim2014.pdf

 

Interesting!

 

I recall that modern MMO formulations include TiO2 (+- 70%) along with ruthenium and iridium oxides in the matrix.

 

I always thought the titanium oxides were "filler" material, or even an inert substrate, BUT maybe it's an integral component of the active anodic process.

 

The article posted bears serious study and consideration.

 

Thanks for sharing it.

 

WSM

Edited March 15, 2020 by WSM

[WSM]

Interesting!

I recall that modern MMO formulations include TiO₂ (+- 70%) along with ruthenium and iridium oxides in the matrix.

 

I always thought the titanium oxides were "filler" material, or even an inert substrate, BUT maybe it's an integral component of the active anodic process.

 

The article posted bears serious study and consideration.

 

This morning I was reviewing some old files and came across a patent that Swede and I were excited about over 8 years ago. It deals with a variation on MMO that uses bismuth/ruthenium oxides with a particular structure that encourages the production of ozone and perchlorate!

 

The file has me starting to renew the excitement Swede and I had about it, back in 2012.

 

I have some research to do on both articles (blue titanium oxide nano-tube anodes AND bismuth-ruthenium oxide anodes) and then discuss the possible benefits here.

 

I'll get back and share what I've learned, when I know more...

 

WSM

Edited March 18, 2020 by WSM

[markx]

Glad to hear that you rediscover your enthusiasm! It's a great feeling....I've also forgooten some topics for years and then refound them to carry on the developments...

[WSM]

Due to the health crisis spanning the globe, bear in mind that spent chlorate electrolyte has a side use as an industrial strength bleach/sanitizer solution. Diluting the solution is advised for use, and wear PPE's when handling it.

 

WSM

[Arthur]

"Bleach" is 3 - 5% sodium hypochlorite. It's the product of a cool cell running gently.

[WSM]

"Bleach" is 3 - 5% sodium hypochlorite. It's the product of a cool cell running gently.

 

In the U.S., bleach is typically 5.25% sodium hypochlorite. If you can determine the concentration of your electrolyte, it's a simple matter to dilute it to regular bleach levels.

 

WSM

[WSM]

"Bleach" is 3 - 5% sodium hypochlorite. It's the product of a cool cell running gently.

If you're set up to make chlorate, Arthur's approach can be used to make your own sanitizer.

 

I think you can use "depleted" electrolyte also. The existing precursors will do a fine job of killing germs, etc.

 

I strongly advise the wearing of non permeable gloves and the use of a respirator and goggles. Also avoid acid, which can release chlorine gas (or worse).

 

When things settle down, we can go back to fabricating oxidizers for articles of celebration.

 

WSM

[Arthur]

Personally I think that the panic buying has stopped. Several people have a ton or two of bog roll. Most people have sufficient staple foods.

 

In all but the worst emergency conditions I'd argue against DIY bleach. At the 5% chlorine that's made it's easy to dilute for cleaning and sanitising, but at an unknown concentration are you going to take the colour from the floor tiles or fail to sanitise.

Edited March 19, 2020 by Arthur

[WSM]

Personally I think that the panic buying has stopped. Several people have a ton or two of bog roll. Most people have sufficient staple foods.

In all but the worst emergency conditions I'd argue against DIY bleach. At the 5% chlorine that's made it's easy to dilute for cleaning and sanitising, but at an unknown concentration are you going to take the colour from the floor tiles or fail to sanitise.

 

Unfortunately, here in the U.S., the panic buying is in full swing, with no signs of letting up yet.

 

If you have no bleach and need some, diluting some electrolyte can get you through till you can acquire the regular stuff. Generally, our electrolyte is very concentrated and diluting it to a more reasonable level with distilled or deionized water would work in a pinch. Try a 10:1, water to electrolyte ratio to start and see if it works for you.

 

10% sodium hypochlorite can be obtained at pool supply stores, if you have access to one that's open. That, too can be diluted for sanitizing purposes.

 

WSM

Edited March 21, 2020 by WSM

[Arthur]

Pool chlorinating tablets are usually available. Pool chlorine test kits will measure the 0 - 10ppm range easily.