Sciencemadness Discussion Board

sodium chlorate production questions

symboom - 29-3-2011 at 21:00

so i have a chlorate cell platinum titanium anode why do i get chlorates at 5 volt 20 amp but at 36 volt 36 amp power source
i only get hydrogen and oxygen.both solutions are hot and concentrated

also my platinum anode electrode got partly melted under water and the melted part is black on the platinum what formed from it melting when the two electrodes accidentally touched

woelen - 29-3-2011 at 22:45

Stupid you :D

Higher voltage only adds more heat and destruction of electrodes! Do not use more than 5 (maybe 6) volts. All excess voltage is converted to heat and nothing more. If you want higher currents, then place electrodes closer to each other, use even higher concentration, or use parallel cells. Increasing voltage is not the way to go!

Btw, please search the forums for more information. On sciencemadness there are tons of posts about chlorate production and many of these will be very helpful.

This may also be interesting: http://www.oxidizing.110mb.com/chlorate/chlorate.html

an interesting discovery

symboom - 30-3-2011 at 07:02

well it was not all bad the black part of my platinum anode when it melted figured out it is platinum oxide and it seems to make the chlorate in a shorter amount of time at 5v and if i use it as the cathode i can electroplate platinum on what ever i use as a anode

pjig - 30-3-2011 at 07:16

"or use parallel cells. "

Could you elaborate on this?

I have two power sources and was considering running two cells independent of each-other. But what you describe sounds more energy efficient, and I'd like to know more.

Are you are describing one power source in parallel to 2 cells? .... forgive me for the misunderstanding if so.

[Edited on 30-3-2011 by pjig]

parallel cells

symboom - 30-3-2011 at 10:32

what he means parallel cells if you have a 12 volt you take two wire leads from the negative and positive side and connected to two cells. both cells will have around 6 volt or less depending on factors that allow it. simultaneously creating (per)chlorate in both containers. but ive read that battery chargers are not good to use because they fluctuate in wattage which is good for charging batteries bad for electrodes though

m1tanker78 - 30-3-2011 at 14:05

Battery chargers have high ripple which is perfectly fine for lead-acid batteries by not so good for circuits that are sensitive to it. If you can get your hands on some beefy capacitors, you can reduce the ripple at the output even at higher currents.

As far as series and parallel....

The electrochemical cell is essentially a resistor. Series resistors add up their resistance. Parallel divide. If you have a 12v source you should put the 2 cells in series. If you have a 5 or 6v source but want to run at a higher current, put the 2 cells in parallel.

You can also combine series and parallel resistances to match your needs.

Tom

roamingnome - 30-3-2011 at 16:38

quote by symboom
platinum oxide and it seems to make the chlorate in a shorter amount of time at 5v

i cannot speak to the potential chemistry happening at the helmholtz layer, maybe the oxide lowers the saddle points of the free energy needed to add oxygen atoms to the Chlorine

very useful book

symboom - 30-3-2011 at 19:58

useful book on perchlorates http://ia600301.us.archive.org/23/items/pwechloratesthei0017...

woelen - 31-3-2011 at 03:30

Quote: Originally posted by symboom  
what he means parallel cells if you have a 12 volt you take two wire leads from the negative and positive side and connected to two cells. both cells will have around 6 volt or less depending on factors that allow it. simultaneously creating (per)chlorate in both containers. but ive read that battery chargers are not good to use because they fluctuate in wattage which is good for charging batteries bad for electrodes though
No, I did not mean this. What you describe is a series connection of cells.

With parallel cells I mean using one powerful 5 ... 6 V power supply, which drives multiple cells, each cell connected to the plus and minus of the power supply. In this way you can make more (per)chlorate per munit of time if your anodes and cathodes are not capable of handling the big current on their own.

[Edited on 31-3-11 by woelen]

symboom - 31-3-2011 at 12:47

your right i am mistaken

grndpndr - 4-4-2011 at 20:22

Can the battery charger be used to keep the battery volts/amps high while using the battery itself to power the cell?Avoiding fluctuations and interruptions in the battery charger circuitry?

Im about to start up my own cell using a computer power supply/2 gallon HDPE bucket?Poor boy so treated graphite gouging rods and SS cathode along with altered computer supply unit that was altered by a friend for trade material he was interested in.

But as I recall somewhere it was suggested the battery charger be used in conjunction with a battery(automotive of course)And the battery itself be used to power the cell.:o



Ive read as much as I can lay my hands on..and absorb! Concerning electrolytic production of chlorates but i still have concerns with storing possibly a few kilos of sodium or K chlorate.Mainly Fire concerns but even explosions if somehow the chlorates contain dangerous impuritys copper being a main concern. I had planned on using rock salt to produce sodium chlorate then metathesis the Na chlorate to whatever might be needed for use in flares,tracer material etc.

Lastly anyone whos using graphite anodes are you also using K dichromate to help in protecting your anode or is the toxicity problematic versus the benefit?

[Edited on 5-4-2011 by grndpndr]

pjig - 7-4-2011 at 15:09

Quote: Originally posted by woelen  
Quote: Originally posted by symboom  
what he means parallel cells if you have a 12 volt you take two wire leads from the negative and positive side and connected to two cells. both cells will have around 6 volt or less depending on factors that allow it. simultaneously creating (per)chlorate in both containers. but ive read that battery chargers are not good to use because they fluctuate in wattage which is good for charging batteries bad for electrodes though
No, I did not mean this. What you describe is a series connection of cells.

With parallel cells I mean using one powerful 5 ... 6 V power supply, which drives multiple cells, each cell connected to the plus and minus of the power supply. In this way you can make more (per)chlorate per munit of time if your anodes and cathodes are not capable of handling the big current on their own.

[Edited on 31-3-11 by woelen]


Ya thats what I was thinking you where implying.. Would a computer power supply be able to take that kind of abuse ? I have 2 that run 200-230W And was considering running 2 independent cells instead of one that was in parallel, but if the power sources can handle it I will give it a go.

woelen - 8-4-2011 at 03:14

Yes, a computer power supply can take that load as long as the total current remains well below the maximum rated current. The maximum rated current is specified for each of the different voltage rails and usually there also is a grand maximum over the entire power supply, either in terms of total current, or in terms of total supplied power.

Mordern power supplies can deliver at least 10 A of current from the 5V rail, but there are supplies which go as far as 30 A. Check the data, printed on the label, attached to the side of the power supply.

pjig - 8-4-2011 at 07:19

I believe that mine is producing 15A to the cell, my tester is giving me trouble, but the last reading was 14.75A.. I have had excessive wear on the anode, and I know that the kc1 levels are very high. That leaves me to believe that the graphite anode and graphite cathode are either too close (3") and or the amperage is to high. Both rods are treated with linseed oil, to reduce wear, but after 12 days I have lost 1/3 of my anode ...I have not maintained the ph with acid.


I switched the polarity and am hoping to finish the run w/o having to do a rod swap.


Any suggestions ?

industrial power supply

symboom - 9-4-2011 at 13:45

ive gone the way of computer supplies as they do not provide not much amperage they take a long time to produce any reasonable amount of perchlorate in a small container in 6 hours i get a bit of an amount at 20A 5 volt Industrial Switching Power Supply which i like the device has no fan so much quieter and more efficient in being able to adjust the amperage defiantly worth the investment.

White Yeti - 29-7-2011 at 05:13

If you're running 20A through a chlorate cell, YOU'RE CRAZY!

Normally you should have some sort of control over the current that flows through the electrodes. The ideal current that should be flowing through your electrodes should be limited to about 90mA/cm2. In that case, your anode could take a current of 20A if it had a surface area of 222cm2, or about a quarter the size of a mouse pad (if you count both sides). Needless to say that your anode would be outrageously expensive. Keep in mind that even platinum isn't indestructible in a chlorate cell. Interestingly enough, platinum has a high electrical resistivity, passing dozens of amps through it would cause it to generate heat and melt. This is the kind of experiment that you have to watch over for several days, and limit the voltage and current that flows through it. Practically, you can run a chlorate cell on only 3 volts. Considering the fact that you are probably also using a small platinum electrode, you shouldn't be using much more than 1A.

Nitro-esteban - 10-9-2013 at 17:53

The electrodes I am using are titanium coated with ruthenium and iridium oxide, I run my cell at 20A and 10V with very good results. I have tested graphite from zinc-carbon cells but they seem to erode quite quickly. How can I treat it to reduce erosion?

AndersHoveland - 10-9-2013 at 17:57

Just to state the obvious, if you pass chlorine gas into an alkaline solution it will form hypochlorite and chloride. A gentle boil for a few minutes will disproportionate the hypochlorite into chlorate.

ElectroWin - 10-9-2013 at 18:40

the chemistry is highly dependent on the current density at the electrode surface.

you must measure the anode surface area that is in contact with the electrolyte,
and use the recommended amount of amperes per square metre.

if current density is too low or too high, you wont make the product you want.

high current densities also degrade anode materials faster.


Pulverulescent - 11-9-2013 at 05:27

Quote:
I have tested graphite from zinc-carbon cells but they seem to erode quite quickly.

Battery cathodes are compressed carbon and are unsuitable as anodes!
Some gouging rods are good quality graphite and stand up well especially if soaked overnight in light linseed oil prior to use . . .
Graphite is easily identifiable by its greyish, rather than black, colour!

Antiswat - 11-9-2013 at 08:31

i have seen stated that nanofibre cloth, wrapped around a graphite anode or cathode should keep it from falling apart, i suppose this would need it to be very well pressed around?
for this some normal organic wire or even plastic should do the job keeping it together
by logic this should work, the the bottom is sealed aswell, when the graphite starts to fall apart, it cannot fall away, and it will still act as electrode, as it keeps the shape
as i have discovered magnetite, Fe3O4 to be found in beach sand (the black type of beach sand) it can easily be taken out by a magnet, this should be done a few times to get a decently pure powder
i suppose same thing could be done with Fe3O4 and nanofibre cloth
keep in mind that there are nobody reporting of having tried this, yet..

can someone tell me why this wouldnt work? just seems too OP.. i mean.. a piece of cloth.. some graphite or magnetite powder and some salt water and a week later add sugar to dry crystals and you got a secondary
there must be something making this impossible, there always is! :D