KonkreteRocketry
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Eletrolysis with chlorides to perchlorate.
I want to make perchlorate from chlorides.
I have lithium salt LiCl and Sodium Salt NaCl.
My electrolysis is powdered by an old computer charger with 20Volts.
The temperature of the cell is around 25 degree Celsius.
Any one of you have any idea how long it will take me to get perchlorate at this rate ? and how to i make sure that it is perchlorate ?
My anode is Iron, it will rust, but i can filter the perchlorate out since they dissolve in water and rust dont and so how long it shall take ? maybe
few days ?
Also, i heard eletrolysis of LiCl is trihydrate is that true ? if it is, how to anhydrate it ?
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elementcollector1
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...None of this will work. Absolutely none of it.
Iron anode = no perchlorate. Not even chlorate, probably. Ferrate? Maybe.
20V = how many amps? Amps determine speed of electrolysis.
25 degrees C = way too low. IIRC, the temperature for perchlorate production was somewhere around 60 C.
chloride -> perchlorate = Wasteful. Convert it to chlorate first, that'll get you better product.
"electrolysis of LiCl is trihydrate" = And...? It doesn't matter how many water molecules you have if you're dissolving it in water.
Besides, where'd you even get LiCl?
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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KonkreteRocketry
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Quote: Originally posted by elementcollector1  | ...None of this will work. Absolutely none of it.
Iron anode = no perchlorate. Not even chlorate, probably. Ferrate? Maybe.
20V = how many amps? Amps determine speed of electrolysis.
25 degrees C = way too low. IIRC, the temperature for perchlorate production was somewhere around 60 C.
chloride -> perchlorate = Wasteful. Convert it to chlorate first, that'll get you better product.
"electrolysis of LiCl is trihydrate" = And...? It doesn't matter how many water molecules you have if you're dissolving it in water.
Besides, where'd you even get LiCl? |
Ok i have a graphite, aluminum, and copper anode also, i can keep it 30 degree.
[Edited on 25-2-2013 by KonkreteRocketry]
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elementcollector1
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Graphite will work to convert to chlorate, and those other two will not.
Then, once you have chlorate, recrystallize for purity and electrolyse a clean solution of that, and you might get perchlorate.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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hissingnoise
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| Quote: | | ]I want to make perchlorate from chlorides. |
Then a bit of reading up on the subject is called for, I'd say . . .
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woelen
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Making chlorates from chlorides already is not trivial, but it can be done at home. But you need suitable electrodes and a fairly powerful power
supply, which works at appr. 5 volts (not 20 V!!) and is capable of delivering at least a few amperes. Temperature is another issue. It is not a
matter of having a cold cell, the cell will easily be too hot. You may need cooling.
I have made a write-up on making KClO3 from KCl, using MMO-anodes in a miniature cell.
http://woelen.homescience.net/science/chem/exps/miniature_ch...
As the web page shows, the making of chlorates is not really trivial. You can use graphite instead of MMO, but then the liquid will become totally
black and it will be quite difficult to purify your chlorate. In that case you'd better start with NaCl instead of KCl, allowing easier separation of
all the carbon from the sodium chlorate.
Making perchlorates at home is MUCH more difficult, unless you have a lot of money to spend on platinum electrodes or are willing to make your own
PbO2-anodes from lead nitrate and an MMO-substrate.
MMO-mesh can be purchased at eBay (the following link is just an example, there are more MMO items on eBay):
http://www.ebay.com/itm/5-x-1-Expanded-Titanium-with-MMO-Coa...
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testimento
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I have a transformer that uses 240VAC mains 20A and outputs 7VAC 685A. This is regulated with triac to 2 or 3.5kW MAX. I have four 400A rectifiers
which decrease the voltage by two units at least when operated and the factual DC output is 4V max at full power, so it looks like I have to rewind
the secondary once again to get it to at least 5VDC for perchlorates.
I was planning on using a pack of PbO2 coated lead sheet electrodes 3mm thick, 20pcs, with 1020 carbon steel cathodes placed every next to other to
create (+-+-+-+) combo, because the electrolysis efficiency seems to be best with smallest gap. The contactor surfaces are aluminium bars that are
connected each to the main rail.
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Manifest
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You can convert Chlorate to Perchlorate by adding Hydrogen Peroxide in an acidic environment so it reduces.
So you'll first need to make chlorate, this seems to be the easiest method and you're guaranteed high purity as long as your chlorate is pure.
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plante1999
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| Quote: Originally posted by Manifest | You can convert Chlorate to Perchlorate by adding Hydrogen Peroxide in an acidic environment so it reduces.
So you'll first need to make chlorate, this seems to be the easiest method and you're guaranteed high purity as long as your chlorate is pure.
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It does not work this way, why does everyone think it does?
The real way is to melt potassium chlorate for a few hours, and leach potassium chloride with water. It is a traditional procedure in old textbook.
[Edited on 13-7-2013 by plante1999]
I never asked for this.
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Manifest
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I was told that it works this way in an acidic environment.
Also, this is why.. https://www.youtube.com/watch?v=9YVsEX-ikUQ
Also, I would advise caution in doing it that way you are heating an oxidizer.
You would need to control the temperature or it will decompose so it doesn't seem very practical for an amateur.
[Edited on 13-7-2013 by Manifest]
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Metacelsus
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The point is that it decomposes and in doing so disproportionates: 4 KClO3 -> 3 KClO4 + KCl (ideally, but in real life some O2 may be lost)
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AndersHoveland
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| Quote: Originally posted by plante1999 | | The real way is to melt potassium chlorate for a few hours, and leach potassium chloride with water. It is a traditional procedure in old textbook.
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I had read about this in an old pyrotechnics forum. In a glass test tube over a flame, you hold the heat just below the decomposition point, allowing
the chlorate to disproportionate into perchlorate and chloride.
Using steady and even application of heat, supposedly the molten potassium chlorate starts to paradoxically solidify, since the melting point of the
perchlorate is higher than the chlorate.
If the molten chlorate starts giving off bubbles, it means that the chlorate is too hot and decomposing into oxygen, and the heat should be reduced.
To get rid of the remaining chlorate, hydrochloric acid is added. This reduces the chlorate to chloride but leaves the perchlorate alone. Then the
much less soluble perchlorate can be crystallized out of the solution.
Another similar method:
Fowler and Grant found that on heating chlorate with silver oxide that the chlorate was completely converted to perchlorate without loss of oxygen,
metallic silver also forming.
J. Chem. Soc. 57, 272 (year 1890)
[Edited on 14-7-2013 by AndersHoveland]
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bfesser
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<strong>AndersHoveland</strong>, I've never had much interest in chlorates and perchlorates—perhaps because I don't pursue
energetic materials—but what you've described is fascinating! Unfortunately, I can't experiment here, but I may see what I can dig up (if
anything) in the literature on what you have described. I'd be delighted to see some photos of this, if anyone wants to <em>safely</em>
try it in microscale. <strong>woelen</strong>'s a good photographer and practitioner of test tube reactions. I wonder if he'd be willing
to do this <em>for science!</em>
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testimento
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| Quote: Originally posted by AndersHoveland |
To get rid of the remaining chlorate, hydrochloric acid is added. This reduces the chlorate to chloride but leaves the perchlorate alone. Then the
much less soluble perchlorate can be crystallized out of the solution.
[Edited on 14-7-2013 by AndersHoveland] |
As far as I know, ammonium perchlorate industry uses the HCl method in a large scale to convert perchlorates into perchloric acid(and then bubble
ammonia through the solution to precipitate AP). Removing the chlorates with small amounts of HCl can be done when the perchlorate(preferable sodium)
is dissolved in water, and the chlorate is released as chlorine dioxide and the solution turns red, and when heated, it will release the gas and
become clear again.
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AndersHoveland
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I read one investigation where they found that ozone could oxidize chloride to perchlorate, though the reaction was very inefficient. Very
interestingly, they found that it was impossible to oxidize chlorate to perchlorate with ozone.
In water, the yield of perchlorate from treating ozone with chlorite is only 2.7%, the remainder only gets oxidized to chlorate.
"Perchlorate Formation by Ozone Oxidation of Aqueous Chlorine/Oxy-Chlorine Species: Role of ClxOy Radicals",
Balaji Rao, Todd A. Anderson, Aaron Redder, W. Andrew Jackson, Environ. Sci. Technol., 2010, 44 (8), pp 2961–2967
"exposing aqueous solutions or Cl(-) coated sand or glass surfaces to O3 (0.96%) generated ClO4(-) with molar yields of 0.007 and 0.01% for aqueous
Cl(-) solutions and 0.025 and 0.42% for Cl(-) coated sand and glass, respectively. Aqueous solutions of Cl(-) produced less ClO4(-) than Cl(-) coated
sand or glass as well as a higher ratio of ClO3(-) to ClO4(-). "
...
"a ClO2(-) solution exposed to O3 produced substantial molar yields of ClO4(-)" (4% molar yield).
"Perchlorate production by ozone oxidation of chloride in aqueous and dry systems", N. Kang, W.A. Jackson, P.K. Dasgupta PK, T.A. Anderson
In other words, only very small traces of perchlorate are formed by oxidizing chloride with ozone. The investigation did not find any traces of
perchlorate when chlorate was treated with ozone.
I think it should also be pointed out here that ozone can oxidize gaseous ClO2 to Cl2O6, a hazardous red fuming liquid. In this case, the reaction
probably proceeds much more readily because ClO2 is a molecular radical (similar to NO2).
[Edited on 14-7-2013 by AndersHoveland]
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