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kweiny
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Hey mysteriusbhoice i saw some of your videos after i built my KClO3 cell and i was wondering how far apart your electrodes are. In my cell it is
about 5-7cm if i recall correctly and when i am running it current does not start flowing until i reach around 14 Volts which seems quite high.
Im using a Ru-Ir MMO Anode (12x30cm i believe) and a Titanium plate as Cathode. I know a mesh would have been better but at the time i bought the
stuff i couldnt find any.
My first run was just a test so i wasnt able to check if Chlorate was actually produced.
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mysteriusbhoice
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Quote: Originally posted by kweiny  | Hey mysteriusbhoice i saw some of your videos after i built my KClO3 cell and i was wondering how far apart your electrodes are. In my cell it is
about 5-7cm if i recall correctly and when i am running it current does not start flowing until i reach around 14 Volts which seems quite high.
Im using a Ru-Ir MMO Anode (12x30cm i believe) and a Titanium plate as Cathode. I know a mesh would have been better but at the time i bought the
stuff i couldnt find any.
My first run was just a test so i wasnt able to check if Chlorate was actually produced.
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Too far apart.
I put mines at 1.3cm to 1.5cm at 5v
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Chemgineer
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I have an MMO mesh anode and a Titanium mesh cathode (both 7.5cm x 5cm) and I have them spaced by 5cm.
I can easily put 9.5amps through this at 5v (normally I just check the power supply is level at about 50watts).
You're electrodes sound huge at 12x30cm, how big is the cell and is the solution saturated? I have issues once with some titanium plate becoming
anodised and causing very high resistance.
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mysteriusbhoice
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| Quote: Originally posted by Chemgineer | I have an MMO mesh anode and a Titanium mesh cathode (both 7.5cm x 5cm) and I have them spaced by 5cm.
I can easily put 9.5amps through this at 5v (normally I just check the power supply is level at about 50watts).
You're electrodes sound huge at 12x30cm, how big is the cell and is the solution saturated? I have issues once with some titanium plate becoming
anodised and causing very high resistance. |
with 2 cathodes you can run that at 15 amps for 200ma/cm^2 which is usually where u wanna run for MMO though you can run it higher granted at
200ma/cm^2 it will last 20 years running 24/7.
The reason why I made mines 1.5cm distance is so that I can run it at lower voltages 3.8 to 4.3 for better efficiency and also the pH control is far
more effective at lower distances rather than large ones where my cell usually remains at 7 the whole time due to addition of CaCl2 + HCl buffer which
can keep the pH low throughout the run.
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kweiny
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| Quote: Originally posted by Chemgineer | I have an MMO mesh anode and a Titanium mesh cathode (both 7.5cm x 5cm) and I have them spaced by 5cm.
I can easily put 9.5amps through this at 5v (normally I just check the power supply is level at about 50watts).
You're electrodes sound huge at 12x30cm, how big is the cell and is the solution saturated? I have issues once with some titanium plate becoming
anodised and causing very high resistance. |
Hi! Sorry for my kind of late response.
Anyways yeah my anode is quite big. Had some thought behind it but it was mainly because it was the easiest size to buy for me. My cell is almost the
same as mysteriusbhoice's just that my electrodes were at the sides of the container. Judging from the pictures he sent, i would guess my container is
almost similar size. 25cm (L) x 8.5cm (W) x 26cm (H). Also i dont believe my solution was saturated. The run was intended to be a test run anyways. I
am going to try my next run hopefully tomorrow with an actual saturated solution. I will see how it goes. As a side note: The cell is not intended to
be either efficient or cost effective.
Cheers
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symboom
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Here is a link to that thread about. "what project are you working on".
http://www.sciencemadness.org/talk/viewthread.php?tid=157373
[Edited on 21-6-2021 by symboom]
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Chemgineer
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Does anyone have an opinion on the addition of potassium dichromate to a chlorate cell and the pros vs cons? I'm told it improves efficiency but on
the negative side it is not as simple to remove from the chlorate produced. I'm of the opinion it isn't worth using but would welcome opinions.
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woelen
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It greatly improves cell efficiency! For me, it even seems to be the difference between easy and quick generation of chlorate and cumbersome and
uncertain running of the cell for a long time, wearing out your anode.
If you use KCl for making KClO3, then removal of the dichromate by recrystallization is very easy. I obtained snow-white KClO3 from my solution with
KClO3 without much effort. On the other hand, if you use NaCl for making NaClO3, then things are quite different. Removing chromate from NaClO3 is not
easily done. NaClO3 is very soluble in water and cannot easily be purified by recrystallization.
See my web page on this: https://woelen.homescience.net/science/chem/exps/miniature_c...
This web page also covers the effect of adding dichromate.
If you don't have dichromate, but you do have chromium(III) sulfate or chrome alum, then dissolve a little of that in concentrated bleach and add so
much bleach that the solution becomes just yellow. Add a single drop of 10% HCl to this and then add the resulting yellow/orange solution to your
solution of KCl. Use simple bleach, without perfumes and without stuff in it to make it more viscous. Only a little chromate is needed.
[Edited on 25-6-21 by woelen]
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Chemgineer
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I've tried using dichromate once before and I got KCLO3 crystals but with a very slight yellow colour with a light shone behind them. Perhaps this
is because they had formed and compacted in the bottom of my cell and then dried with dichromate residue in between.
Perhaps a rinse in nearly saturated KCL would dissolve the dichromate as it is very slightly more soluble than chlorate?
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yobbo II
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The Chlorates and Perchlorates page
http://www.pyrobin.com/files/ChloratesAndPerchlorates.zip
If you download the file at this link (41MB) and look in the cathode section it willl give information on using (or not) dichromates.
Yob
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vanBassum
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Oh, this thread has progressed significantly since I last logged-in. 
I run my cell with and without additives, and I never had problems without the additives. But I didn't take the effort to measure the efficiency. The
main reason for not using additives is the incompatibility of chromates with the PbO2 electrode. You can get rid of the chromates with barium, but
that will introduce another not so safe contamination. I opted to just not use any additives, although it costs a bit more energy it saves me the
hassle. Besides, electricity is quite cheap, the only real advantage for me would be the reduced wear on the anodes. A sidenote is necessary, I just
use regular tap water that probably contain some impurities that may influence the cell. Also, the glue and plastics I use could be a source of
contamination.
By the way, I stopped trying to seal my cells. I just run them outside, far away from everything. A larger bucket upside down over the cell with a
stone on top prevents rain from falling in. This is a bit caveman style, but it's really practical.
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Chemgineer
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| Quote: Originally posted by vanBassum | By the way, I stopped trying to seal my cells. I just run them outside, far away from everything. A larger bucket upside down over the cell with a
stone on top prevents rain from falling in. This is a bit caveman style, but it's really practical.
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What is you solution to connecting onto your electrodes without corrosion problems if you have an open cell?
I might start using rain water instead of tap water, I collected a fair few litres, it's currently going green despite my best efforts with a UV light
but the a Chlorate cell should sterilise it!
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macckone
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chemgineer,
green as in something growing or green as in metal contamination?
nothing should be able to grow in a 30% salt solution with hypochlorite and chlorate present.
It sounds like your tap water has metal contamination or one of your electrodes is decomposing.
Or possibly corrosion from your wire is finding its way into the cell.
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Chemgineer
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| Quote: Originally posted by macckone | chemgineer,
green as in something growing or green as in metal contamination?
nothing should be able to grow in a 30% salt solution with hypochlorite and chlorate present.
It sounds like your tap water has metal contamination or one of your electrodes is decomposing.
Or possibly corrosion from your wire is finding its way into the cell. |
Sorry should have been more clear, the green is growing in the rain water before i've used it for anything. Just plain rain water.
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yobbo II
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Green is all the rage nowadays!
Has anyone noticed MMO passivating in non pH controlled cells. I have ran some non pH controlled cells and the MMO passivates after a few days. I
cannot say if it would do the same in a cell that is controlled. I would need to run some that were pH controlled versus not pH controlled to see.
The MMO is old (lying around for years) bought from 'laserred' on ebay.
............This is a bit caveman style,.................
It's called caveman style if you are from the country. Getto style if you are from the city.
Yob
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vanBassum
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Haha you are completely right about the caveman style.
My cell is still comparable to the photo I uploaded a while back. Although, I don't bother sealing the cell anymore. Just a loose lid on the jar is
good enough.
About the green stuff, that stuff is probably organic, organic + chlorate is a bad idea for obvious reasons. Why would you take the risk? Water is
cheap.
By the way, came up with a theory to check the progress of the cell:
First take a sample and boil down until all water is gone.
You should now be left with chloride and chlorate.
Weight the solid and take note, we will call this measurement A.
Now load the solid into a test tube and heat, this will decompose the chlorate into chloride. The oxygen will escape.
Weight again, this will be B.
Now figure out how much oxygen by weight is in your compound:
For NaClO3 this is 45% or 0.45, this will be P.
To calculate the percentage of chlorate that was initially in the cell use the following formula:
Y = (A - B) / (A * P)
Example:
10 gram of solid. (mixture of 50/50 NaClO3 and NaCl)
After decomposition, you are left with 7 gram.
(10 - 7) / (10 * 0.45) = 0.66 → 66% chlorate in the initial sample.
Came up with this yesterday evening, so I hope to try this today.
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Chemgineer
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I suppose a rough estimate could be got by just weighing it in a controlled volume and work out density of the anhydrous powder and compare to what
chlorate should be.
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vanBassum
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Sure, but getting an accurate measurement of volume would be difficult. An option would be to first weight it out and then add it to a grad cylinder
prefilled with water and see how much the level rises. That would be simpler compared to the decomposition. The decomposition method could also be
used slightly different by catching the oxygen and measuring the volume of that.
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Fantasma4500
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i have a few tips for processing the finished chlorate
wash it once then douse it in acetone
this will first up react with the bleach, eliminating it
secondly, you pour that acetone back out and the chlorate is now saturated with acetone- dries very fast
then you dump it on a stack of newspaper and let the paper such up the liquid
larger pieces you can smash up by grinding with the bottom of a glass jar, pressing it downwards while circling around the chunk, this crushes up even
very hard chunks of whatever
filling a plastic bottle half with water and throwing in freezer, pouring in water will give you very quick to go "icewater" for rinsing the chlorate,
also
in general with electrolysis i would always advise starting off with sodium chloride, higher density of chlorate in finished solution
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