making potassium (per) chlorate

[THEONE]

I measure the tenperature today and i found it 63 oC. I am thinking now to isolate the glass jar so the temperature will be increased. I have seen other people operates their cell at 80-90 oC with great results. Edited February 11, 2015 by THEONE

[WSM]

I measure the tenperature today and i found it 63 oC. I am thinking now to isolate the glass jar so the temperature will be increased. I have seen other people operates their cell at 80-90 oC with great results.

 

I think 63^oC is hot enough. Insulated glass may or may not handle the heat (I'm not sure). I'd only feel comfortable going to 80-90^oC in a cell made of CPVC (which can withstand up to 93^oC). Borosilicate (Pyrex) glass certainly would work, though.

 

WSM

[THEONE]

 

I think 63^oC is hot enough. Insulated glass may or may not handle the heat (I'm not sure). I'd only feel comfortable going to 80-90^oC in a cell made of CPVC (which can withstand up to 93^oC). Borosilicate (Pyrex) glass certainly would work, though.

 

WSM

I do not think so it will be a problem. The temperature evenly and easily is going up. Usualy the suddenly and not evenly temperature make the glass to broke

[Arthur]

If you are concerned about the cell container then please stand it in a plastic bowl of sufficient capacity. Chlorate is a plant killer.

[THEONE]

The plastic will not be hot enough to became soft ? Edited February 12, 2015 by THEONE

[THEONE]

Can a cobalt oxide electrode make chlorates or perchlorates ?

 

US3399966

Edited February 12, 2015 by THEONE

[pyrojig]

Just because a "oxide" is able to be used in electrolysis , doenst mean that it is a good candidate for perch production . It is however claimed to produce chlorate. but Im not sure if it can even compete with MMO as for longevity etc.

[THEONE]

I have seen that Sno2 is used as an interface between titanium and Pbo2. Also for this reason i guess Sno2 can make chlorates, but i am not sure. I was wondering if Sno2 is better for chlorates and as an interface between titanium and Pbo2 than Mno2

[WSM]

If you are concerned about the cell container then please stand it in a plastic bowl of sufficient capacity. Chlorate is a plant killer.

 

I describe chlorate (potassium and sodium) as an indescriminant herbicide.

 

WSM

[WSM]

The plastic will not be hot enough to became soft ?

 

It depends on the plastic. PVC is good to 60^oC, and CPVC to 93^oC.

 

If you Google search, you can find lists of polymer thermal properties.

 

WSM

[WSM]

I've made up some perchlorate electrodes, photographed them and finished part eight of my Homegrown Oxidizers articles for the PGI Bulletin. In part nine I'll run the platinum and LD electrodes and prove perchlorate was formed by using methylene blue solution.

 

After the "proof-of-Concept" demonstration, I'll have to set up and run a sodium chlorate cell to make feed stock for the perchlorate cell. It seems we need 600g NaClO₃/L H₂O (or roughly 5 lbs/gallon of water) for the perchlorate cell electrolyte. I have a lot of work to do and little time to accomplish it.

 

WSM

[pyrojig]

Will you be doing a CE comparison maybe later on the LD v.s. the Platinum ? I am curious about which is a better producer, and more so, ....which can survive multiple runs (for production on a amateur scale) ...

I eagerly await your findings . I hope you get a chance to make head way ( time) . Glad to see your producing some nice work ( articles)

[WSM]

Will you be doing a CE comparison maybe later on the LD v.s. the Platinum ? I am curious about which is a better producer, and more so, ....which can survive multiple runs (for production on a amateur scale) ...

I eagerly await your findings . I hope you get a chance to make head way ( time) . Glad to see your producing some nice work ( articles)

 

Thanks, pyrojig. There's a lot of work left to do. Industry usually gets a CE between 82% to about 90%.

 

This morning I filled the tubular leads of my platinum and LD electrodes. The platinum and titanium electrode leads are small enough that I used lead-free solder alone. The LD and titanium tubular leads are bigger in diameter, so I cut two pieces of solid 4 AWG wire to put in them before filling the rest of the ID's with the lead-free solder. The lead-free solder is 95% tin and 5% silver, so it's 5x more conductive than titanium and should run MUCH cooler than titanium alone.

 

I plan to set up my small experimental perchlorate cells and run them as a proof-of-concept as stated earlier.

 

WSM

[pyrojig]

Hey with all that "extra time" you have there ...., you should throw a set of LD electrodes for the Bucket Cell together , and I can run some tests as well . I'd pay for them of course ..... . . Your an inspiration , and a great mentor. Thank you , for the countless hours or research and sharing you give so freely !!! It is a treat for us members here on APC. I wish I had your drive and skill to build such amazing creations . Please keep up the great work!!!!!! And thank you again .!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[MrB]

you should throw a set of LD electrodes for the Bucket Cell together , and I can run some tests as well . I'd pay for them of course ...

If he starts throwing them together, then there is issues with the world. But yeah, i'm waiting for a report on how those work out, and how he went about things to get the end-results.

No pressure WSM, yesterday is good enough. ;- )

B!

Edited March 15, 2015 by MrB

[barzn]

Hi,

I'm new to this forum but have gone pretty much hours of reading and learning through it, and i have to say that there are plenty of knowledgable and experienced useres here that is a pleasure to read their posts, So keep up the good work and sharing of your knowledge!

I'm planning on setting up one or two cells to produce Chlorate and Perchlorate, and i would really appreciate your help!

After reading all kinds of sources and methods and learning the theory for that cause, I pretty much understand all there is to it, except the proportions and relations between electrolyte to voltage&current to electrodes (surface area, material, spacing).

In practice - to explain my difficulty of understanding it I'll explain my setup:

 

Power Supply - I have a regulated DC power supply, capable of adjustable 0-16V and 0-10A output.

Anodes - I have 3 types of anodes: Platinum plated Titanium, TSLD and Ruthenium-Iridium Oxide (Titanium substrate MMO) - All of them in a mesh plate shape.

Cathodes - A few plain/mesh sheets of Titanium (I believe it is Grade 1, but could be anything from Grade 1 to 4, which is unalloyed).

Electrolyte - Both for Chlorate and Perchlorate, I plan on using Sodium Chloride with cell additives as an electrolyte (But go from Na Chlorate -> Na Perc).

Cell Body - Either Boro-Silicate glass or some sort of heat resistant transparent plastic in the right size.

Temperature and pH control - Hydrochloric acid and Sodium Hydroxide to control the pH, Temperature - I'll figure something out as i don't have some sophisticated equipment.

Treating the electrolysed solution - After a run, Boiling to destroy Hypochlorite to obtain Chlorate, or destroy the Chlorate with metabisulfite etc. to obtain Perchlorate. Afterwhich, Methathesis reaction takes place to convert to K/Ba/Other Chlorate/Perchlorate. Followed by multiple recrystalizations and filtering.

 

Now all of this is what i understant (Correct me if someting wrong/needs to be improved), What i don't understand is those very important elements that affects a lot the CE:

 

1. How much voltage and current is to be used on a given volume of fully saturated electrolyte (Max. NaCl dissolved in water) with given electrodes.

For my understanding, there are lots of variables here - Voltage, Current, Saturation level of electrolyte (Resistance), Electrodes (Material, Current density, Surface area, distance between each other).

2. My main issue is how not to damage the electrodes, So i have to figure out the current to send through the them and the distance between them, given different electrode material and size.

3. I have read different things regarding the current, but can't get the hold over the "trick", and how to figure out the current density/surface area of an anode - One saying as a rule of thumb to use 2A for every 100ml of electrolyte, Other calls for few mA per cm^2. Also, how can one calculate a mesh plate surface area? as it is not a continous surface area like a solid plate.

4. What would be the current to produce Perchlorate, while providing best conditions and avoiding anode errosion?

5. What additives should i use with each elecrtrode type (If at all)? As i read that Flouride can damage Ti substrated anodes (which is essentially all of my anodes).

 

I would really appreciate your help and to hear your thoughts on my method, Thanks alot!

Best regards,

Bar.

[WSM]

If he starts throwing them together, then there is issues with the world. But yeah, i'm waiting for a report on how those work out, and how he went about things to get the end-results.

No pressure WSM, yesterday is good enough. ;- )

B!

 

My pace is slow and methodical (and pyrojig knows this ). I go as fast as time and opportunity allows, not withstanding all the other things in life demanding my attention. I need to finish the perchlorate electrodes and small, research cells before I can run and test them (hopefully very soon).

 

In studying perchlorate cells, I'm getting a feel for how they're "supposed" to work. If I'm correct, they're different enough from chlorate cells to demand special attention to the particular details, so we don't kill the anodes prematurely. I'll include a lot more detail when I test my theories and run the cells.

 

WSM

[WSM]

Hi,

I'm new to this forum but have gone pretty much hours of reading and learning through it, and i have to say that there are plenty of knowledgable and experienced useres here that is a pleasure to read their posts, So keep up the good work and sharing of your knowledge!

I'm planning on setting up one or two cells to produce Chlorate and Perchlorate, and i would really appreciate your help!

After reading all kinds of sources and methods and learning the theory for that cause, I pretty much understand all there is to it, except the proportions and relations between electrolyte to voltage&current to electrodes (surface area, material, spacing).

In practice - to explain my difficulty of understanding it I'll explain my setup:

 

Power Supply - I have a regulated DC power supply, capable of adjustable 0-16V and 0-10A output.

Anodes - I have 3 types of anodes: Platinum plated Titanium, TSLD and Ruthenium-Iridium Oxide (Titanium substrate MMO) - All of them in a mesh plate shape.

Cathodes - A few plain/mesh sheets of Titanium (I believe it is Grade 1, but could be anything from Grade 1 to 4, which is unalloyed).

Electrolyte - Both for Chlorate and Perchlorate, I plan on using Sodium Chloride with cell additives as an electrolyte (But go from Na Chlorate -> Na Perc).

Cell Body - Either Boro-Silicate glass or some sort of heat resistant transparent plastic in the right size.

Temperature and pH control - Hydrochloric acid and Sodium Hydroxide to control the pH, Temperature - I'll figure something out as i don't have some sophisticated equipment.

Treating the electrolysed solution - After a run, Boiling to destroy Hypochlorite to obtain Chlorate, or destroy the Chlorate with metabisulfite etc. to obtain Perchlorate. Afterwhich, Methathesis reaction takes place to convert to K/Ba/Other Chlorate/Perchlorate. Followed by multiple recrystalizations and filtering.

 

Now all of this is what i understant (Correct me if someting wrong/needs to be improved), What i don't understand is those very important elements that affects a lot the CE:

 

1. How much voltage and current is to be used on a given volume of fully saturated electrolyte (Max. NaCl dissolved in water) with given electrodes.

For my understanding, there are lots of variables here - Voltage, Current, Saturation level of electrolyte (Resistance), Electrodes (Material, Current density, Surface area, distance between each other).

2. My main issue is how not to damage the electrodes, So i have to figure out the current to send through the them and the distance between them, given different electrode material and size.

3. I have read different things regarding the current, but can't get the hold over the "trick", and how to figure out the current density/surface area of an anode - One saying as a rule of thumb to use 2A for every 100ml of electrolyte, Other calls for few mA per cm^2. Also, how can one calculate a mesh plate surface area? as it is not a continous surface area like a solid plate.

4. What would be the current to produce Perchlorate, while providing best conditions and avoiding anode errosion?

5. What additives should i use with each elecrtrode type (If at all)? As i read that Flouride can damage Ti substrated anodes (which is essentially all of my anodes).

 

I would really appreciate your help and to hear your thoughts on my method, Thanks alot!

Best regards,

Bar.

 

Greetings Bar,

 

Welcome to the discussion. First of all, you asked everything in one post. It might be easier to handle in small bites. That said, I'll try to answer some points that stood out in my mind.

 

"1. How much voltage and current is to be used on a given volume of fully saturated electrolyte (Max. NaCl dissolved in water) with given electrodes.

For my understanding, there are lots of variables here - Voltage, Current, Saturation level of electrolyte (Resistance), Electrodes (Material, Current density, Surface area, distance between each other)."

 

The typical electrolyte for optimal performance is all the salt that will dissolve at STP (a scientific acronym referring to Standard Temperature and Pressure) and usually means what dissolves at 25^oC and 1 atmosphere. According to the Merck Index, 13th Ed., at 25^oC, 1 gram of sodium chloride is soluble in 2.8 ml water. A little math reveals that's about 357g/L, and in practice, anything close usually works just fine. If you choose to be as accurate as possible, get pure NaCl and distilled water and go from there.

 

My best recommendation is to separate the two processes (chlorate and perchlorate) from each other rather than try to go directly from chloride to perchlorate. Your life will be simpler and the equipment you've acquired will survive longer.

 

That said, to make chlorate use MMO for your anode and titanium for your cathode. To improve CE, timed dilute HCl injections will help, but NaOH would only be neccessary if you overdose the cell with HCl. I never use alkali because the cell runs to the alkaline naturally. The ideal pH is 6.8 for the optimal operation using the least current to make the chlorate.

 

Electrode distance in industry is typically "as close as possible" and often as close as 3mm. Further apart adds internal cell resistance which wastes power by generating heat. The heat isn't a total waste, because it improves the cell efficiency.

 

If you ask specific questions, one at a time, it's easier to answer and usually several answers from different people will be posted.

 

WSM

[MrB]

 

My pace is slow and methodical

 

Your blogg-posts have been a small miracle, to read and actually be able to understand a little something means a lot. I still got close to 50 kilos of perch, i'll be fine for some time still, so i'm just keeping tabs on this thread, and try to let you know your efforts are appreciated every now and then. All in it's own time.

B!

[barzn]

Thank you very much for the reply! I did have a feeling that i'm over-flooding with too much information and questions hehe

 

"The typical electrolyte for optimal performance is all the salt that will dissolve at STP (a scientific acronym referring to Standard Temperature and Pressure) and usually means what dissolves at 25^oC and 1 atmosphere. According to the Merck Index, 13th Ed., at 25^oC, 1 gram of sodium chloride is soluble in 2.8 ml water. A little math reveals that's about 357g/L, and in practice, anything close usually works just fine. If you choose to be as accurate as possible, get pure NaCl and distilled water and go from there." - That is acctually well understood for me, no problem here at all.

 

"My best recommendation is to separate the two processes (chlorate and perchlorate) from each other rather than try to go directly from chloride to perchlorate. Your life will be simpler and the equipment you've acquired will survive longer." - I actually mentioned it, It is how i plan to go about it and get both of the worlds

 

WSM

 

As you said, I'll try to start with my main problem of which i don't understand the very concept:

"proportions and relations between electrolyte to voltage&current to electrodes (surface area, material, spacing)"

"I have read different things regarding the current, but can't get the hold over the "trick", and how to figure out the current density/surface area of an anode - One saying as a rule of thumb to use 2A for every 100ml of electrolyte, Other calls for few mA per cm^2 of surface area. Also, how can one calculate a mesh plate surface area? as it is not a continous surface area like a solid plate."

 

Practicly speaking, what i mean is - for example i have a Platinum anode that is 2inch*3inch and a Titanium cathode with the same size - how much electrolyte should i use and how much current to send through (which differece if i'm making chlorate or perchlorate? whats the minimum for each?).

I'm trying to find the "equation" here that takes into account all the varaibles i have mentioned in the previous post.

I also wouldn't like my anodes getting useless by using too much current - so i'm trying to understand what is this "too much", as it is relative to all conditions..

I'm starting to get confused here

 

Thanks alot!

[WSM]

 

Your blogg-posts have been a small miracle, to read and actually be able to understand a little something means a lot. I still got close to 50 kilos of perch, i'll be fine for some time still, so i'm just keeping tabs on this thread, and try to let you know your efforts are appreciated every now and then. All in it's own time.

B!

 

Thanks, MrB. We'll see where this all takes us...

 

WSM

[MrB]

Also, how can one calculate a mesh plate surface area? as it is not a continous surface area like a solid plate.

 

I've been told a mesh provides approximately the same area as a plate would.

 

"I have read different things regarding the current, but can't get the hold over the "trick", and how to figure out the current density/surface area of an anode - One saying as a rule of thumb to use 2A for every 100ml of electrolyte, Other calls for few mA per cm^2 of surface area.

 

The anode will determine the max you can put in to the cell. It will simply fall apart from overheating if you push to hard. Different types of anodes, different mA's as max. I've been hearing 300mA as a rule of thumb, a lot, but where the number comes from.... No idea.

At the same time the cell will overheat if you have a small volume in relation to what your anode can deal with. Your better of with "to large" a volume, and insulating the cell slightly to get the working temperature you need / want. Which also is dependent on the anode, with LD i hear the limit is lower then you'd really want the cell at, 50-55c as an absolute max.

 

I also wouldn't like my anodes getting useless by using too much current - so i'm trying to understand what is this "too much", as it is relative to all conditions..

 

You and me both. I think i want a stainless steel cell, with a rod in the center, and a round, mesh LD anode around the rod. Using the cell as cathode, and using wishful thinking to control the temperature. But the anode for something like that would be fairly large, and more then likely, custom made, making it quite expensive.

 

I'm starting to get confused here

 

Thats what so great with WSM's bloggposts. They actually make (well, some) sense. I'm using a lot of "wait and see", and hope that he gets around to them LD anodes at some point.

 

 

Thanks, MrB. We'll see where this all takes us...

 

To the moon, and back. Your the man.

B!

[WSM]

Thank you very much for the reply! I did have a feeling that i'm over-flooding with too much information and questions hehe

 

 

As you said, I'll try to start with my main problem of which i don't understand the very concept:

"proportions and relations between electrolyte to voltage&current to electrodes (surface area, material, spacing)"

"I have read different things regarding the current, but can't get the hold over the "trick", and how to figure out the current density/surface area of an anode - One saying as a rule of thumb to use 2A for every 100ml of electrolyte, Other calls for few mA per cm^2 of surface area. Also, how can one calculate a mesh plate surface area? as it is not a continous surface area like a solid plate."

 

Practicly speaking, what i mean is - for example i have a Platinum anode that is 2inch*3inch and a Titanium cathode with the same size - how much electrolyte should i use and how much current to send through (which differece if i'm making chlorate or perchlorate? whats the minimum for each?).

I'm trying to find the "equation" here that takes into account all the varaibles i have mentioned in the previous post.

I also wouldn't like my anodes getting useless by using too much current - so i'm trying to understand what is this "too much", as it is relative to all conditions..

I'm starting to get confused here

 

Thanks alot!

 

Hi barzn,

 

The biggest difficulty is calculating the surface area of the anode mesh. Fortunately, with the MMO and to some degree the LD, one can assume the surface area to be the same as flat sheet anodes due to the increased surface area of the coatings on a microscopic level. With platinized titanium, smooth surfaces have less surface area than a dull (uneven) surface.

 

The 2" by 3" anode equals 38.7 cm² (multiply each square inch by 6.45 to get square centimeters) and if only one cathode is used at 0.3A per cm² then the current demand is 11.61A maximum (and double that if two cathodes surround the anode). If lower current is used, less stresses on the anode will result. Also, regarding platinized anodes, lower temperatures (30^oC) give higher CE's (90%+) than higher temperatures do. Industry uses cooling water running through cathode plates to keep the cell temperature in the desired range.

 

I've found that solid plate, CP titanium cathodes work best in my experiments, rather than mesh. It's also less expensive than mesh.

 

Also, the voltage is usually between 6.2-6.8 Vdc in industrial setups using platinum anodes.

 

WSM

[WSM]

Thats what so great with WSM's bloggposts. They actually make (well, some) sense. I'm using a lot of "wait and see", and hope that he gets around to them LD anodes at some point.

 

To the moon, and back. Your the man.

B!

 

I've focused so much on extending the capabilities of chlorate cells, that I've largely ignored the next logical step; making perchlorates from chlorates.

 

As industry avoids using potassium salts (except in the final exchanges) in the perchlorate process, due to solubilities of potassium salts and sodium salts (potassium salts get less soluble as the oxygen levels raise and sodium salts get much more soluble as the oxygen levels raise), I've reallized the best approach for me is to make potassium chlorate directly from potassium chloride and potassium perchlorate from sodium chloride to sodium chlorate to sodium perchlorate to potassium perchlorate by exchange with KCl. So a two step process appears to be the best method for me.

 

I've got some experiments to run very soon and we'll see if they work as well as I hope they will. Either way, I'll post the results here.

 

WSM

[WSM]

Thats what so great with WSM's bloggposts. They actually make (well, some) sense. I'm using a lot of "wait and see", and hope that he gets around to them LD anodes at some point.

To the moon, and back. Your the man.

B!

 

Actually, I'm using some Lead Dioxide AND Platinum anodes in my perchlorate experiments, soon. There are too many variables to accurately predict how they'll compare, but I'm starting to suspect I'll get better performance from the LD (call it a hunch).

 

WSM