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Pulverulescent
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| Quote: | | Dann, very nice, are you gonna make some organic perchlorate salt? If yes, try Biuret Perchlorate, in small quantity. It may be interesting.
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Too interesting sometimes ─ don't forget ─ organic perchlorates have a real baaad reputation!
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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Adas
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Yeah, that's why I mentioned to do it in small quantity 
Rest In Pieces!
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dann2
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Actually I am putting it into a Perchlorate cell to keep pH down. Here is little need to keep pH down AFAIK but just doing it anyways.
Dann2
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Pulverulescent
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| Quote: | | Actually I am putting it into a Perchlorate cell to keep pH down. |
'Not quite sure what you mean there, dann2
. . . ?
70% HClO<sub>4</sub> is easily storable in Merck safebreak bottles!
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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dann2
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I am storing it in a plastic bottle. It's around 50% stuff, as I diluted the 72% stuff I made with water.
I am putting small amounts of the Perchloric acid into a Perchlorate cell that I am running to lower the pH of the cell.
HCl acid puts a Perchlorate cell CRAZY.
I don't think there is any benifit in running a Perchlorate cell at a low pH anyways buts thats another story.
They seem to drift to a high pH of there own accord. Will post in Technochem. some more blow by blow details.
Dann2
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Pulverulescent
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| Quote: | | I am putting small amounts of the Perchloric acid into a Perchlorate cell that I am running to lower the pH of the cell. |
What???
You're putting one of the strongest, most highly oxidising acids into a perchlorate cell!
You gotta' be kidding me! ( )
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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Adas
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I also don't understand why he is trying to lower the pH. The pH itself rises up in time, because NaOH is formed and not all chlorine reacts with it.
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Pulverulescent
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I've only ever made fuck all NaClO<sub>4</sub> even though I have the Pt/Ir wires for years!
I remember thinking it'd be nice to go directly from chloride to perchlorate!
But the fairly moderate conductivity of the alloy soon made me reconsider and I quickly lost all interest . . .
But now that I've just kicked a 33 year long, several joints a night, dope habit I'm a'rearin' to go!
I'll get out ye olde gouging rods (assuming I can still find them), make some chlorate, separate by fractioning and then add that
all-important extra O! ()
The chlorate is the hard part, what with filtering, adjusting pH, getting adequate current and fractioning/filtering again!
I used to have some NH<sub>4</sub>ClO<sub>4</sub> lying around from time immemorial too ─ finding that'll be fun as the
biro-ink on all my labels has, long ago, succumbed to the passage of time! ( )
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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Adas
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I was making NaClO3/NaClO4 once using 5A, I let it run for like a month with graphite electrodes (which have been eaten fast), but the (per)chlorate
seemed to be fairly stable to friction when mixed with sugar. It also contained a lot of contaminants, for sure (NaOH, NaHCO3.....).
I think you don't really have to do any recrystallization and all the crap, just keep the temp high enough to destroy NaClO and create NaClO3, then
NaClO4.
Rest In Pieces!
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Pulverulescent
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| Quote: | I was making NaClO3/NaClO4 once using 5A, I let it run for like a month with graphite electrodes (which have been eaten fast), but the (per)chlorate
seemed to be fairly stable to friction when mixed with sugar. It also contained a lot of contaminants, for sure (NaOH, NaHCO3.....).
I think you don't really have to do any recrystallization and all the crap, just keep the temp high enough to destroy NaClO and create NaClO3, then
NaClO4. |
5 Amps, eh?
'Small wonder you had to do such a looong run! ()
And while graphite will produce perchlorate, the amounts would be negligible, at best!
It is, of course, best not to have chloride in a perchlorate-cell if using Pt, and having Pt as cathode is advantageous to avoid loss of metal during
a run!
Polarities should be switched occasionally to replace the Pt transferred from anode to cathode . . .
And graphite anodes that erode quickly are cheap, polymer-bound graphite powder types!
For the very best results you need the compressed, thermally-bound variety of gouging rod!
They're hardwearing and produce no contaminant other than fast settling, graphite sludge!
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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dann2
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AAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHH Another 'making Perchlorate using Graphite' dude
Stating that you had a cell run at 5 amps is a bit like saying you had a mechanically propelled vehicle that did 5 miles to the gallon.
(You need to mention was the vechicle a mope head, small car, large car, truck, bulldozer, a ship....)
If the cell is small it will finish in no-time-a-tall-a-tall.
Going back to the Perchloric acid. It has been used to lower pH in Perk. cells in some of the studies in Journals etc.
How else would you lower it?
HCl is out unless there is very little Chloride in the cell, because once you start adding Chloride (via the HCl ) Chlorine starts to creep out of the
cell and this is inclined to raise pH. HCl acid does lower pH if there is little or no Chloride there already and you just add enough HCl acid to do
the job.
You could use Sulphuric acid I suppose but then you are starting to contaminate with Sulphate.
Just to note: I am not argueing that it is necessary or even desirable to controll the pH of Perchlorate cells.
I was just having a look to see how to do it since I read that high pH (allegedly) dissolved LD Anodes. I cannot say I have observed any LD
dissolution due to high pH.
Dann 2
[Edited on 1-2-2012 by dann2]
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Pulverulescent
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NaClO<sub>3</sub> is a neutral salt!
Ideally, the perchlorate-cell should contain no chloride, therefore no alkaline drift will occur.
The chlorate is oxidised by the nascent oxygen produced at the anode . . .
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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woelen
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Failure while method looks promising
I purchased some ammonium perchlorate, hoping to be able to make perchloric acid, according to the method, mentioned in the attached file. I tried
several times, but the experiment is a total failure each time.
I took ammonium perchlorate, nitric acid (65%) and hydrochloric acid (30 ... 35%), in the quantities as mentioned in the attached document, but scaled
down a factor 50. The acids are general lab grade and are clear colorless liquids, not the usual yellow stuff from a hardware store. The ammonium
perchlorate is from a seller, geared towards pyrotechnics. It is a coarse crystalline solid which dissolves completely and gives perfectly clear
solutions in distilled water. Normally one has to ballmill this coarse material when used for pyrotechnics, but for my use in chemical experiments it
is perfectly OK.
When heating the mix, the solid ammonium perchlorate dissolves with difficulty. At a certain point in time, a lot of gas is produced (first, a lot of
orange gas is produced, probably a mix of NOx and ONCl from the aqua regia formed), but lateron the gas mix becomes colorless. The liquid goes from
colorless, when cold and just mixed, to yellow/orange, when heated and lateron it becomes colorless again. I kept on heating and had the liquid
boiling for a long time and in the meantime producing nasty dense fumes. But finally, the clear liquid more or less solidified and a white crystalline
mess was produced. At that point I stopped heating and quit the experiment. I have the idea that I just boiled off water and acid.
I expected that after some time I would end up with a clear liquid, which remains clear without any solid matter in it. I have to conclude that this
method of making perchloric acid does not work very well, at least not in my setup. Are there any other people who have experience with this method?
It sounds very good. Coarse ammonium perchlorate without anticaking agents can be obtained fairly easily where I live and it would be a great source
of the hard to obtain perchloric acid if this method works. Any suggestions from other people are welcome. Simply heating a mix for a while does not
work, you just boil off most of the acid. Probably part of the ammonium is destroyed (you get a lot of colorless gas), but only a part. Maybe the
colorless gas was only in small amounts. Due to the boiling it may look much more impressive than it actually was (small bubbles of gas can act as
starting points for formation of large gas bubbles from boiling liquid).
Attachment: The preparation of Perchloric acid.pdf (431kB)
This file has been downloaded 562 times
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Pulverulescent
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─ woelen, I believe you'd have had better results using the sodium salt!
A large excess of HCl is needed though.
Precipitating NaCl at low temperature should work well.
You can then recover unreacted HCl, leaving only slightly NaClO<sub>4</sub> contaminated acid. ()
Distilling at almost any pressure is fairly loaded . . .
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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woelen
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Yes, I know of the NaClO4-method, but I have NH4ClO4, not NaClO4 (the latter is harder to obtain, it is a much less common reagent). The principle
behind the NaClO4-method is simply precipitating out the sodium ions and then boiling off excess HCl. The principle behind the NH4ClO4 method is
destruction of NH4(+) ions by means of the combination HNO3/HCl and then boiling off excess HNO3/HCl. In theory this should work nicely according to
the attached paper, but in practice it is a lot harder. NH4(+) is not that easily oxidized by the HNO3/HCl combo.
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Pulverulescent
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| Quote: | | Yes, I know of the NaClO4-method, but I have NH4ClO4, not NaClO4 (the latter is harder to obtain, it is a much less common reagent).
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I'm surprised woelen, as the sodium salt is the basic product!
I bought some years ago from Lennox; reasonable price 99% purity.
You could, though, see black flecks of PbO<sub>2</sub>!
Times have changed!
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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woelen
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NaClO4 may be the basic product, but in commerce the only two perchlorates which are easy to obtain are KClO4 and NH4ClO4, because of their use in
pyrotechnics. I have the strange situation that I can easily obtain pyro-related chemicals where I live, but I am not allowed to use these chemicals
for pyrotechnics purposes (over here in NL pyrotechnics is totally forbidden, in any form, unless you have a special license, e.g. for industrial
purposes). Perchloric acid and NaClO4 on the other hand are special purpose reagents and these are not easy to obtain. I have a small quantity of
HClO4, but it would be great if I can make more of this on demand from chemicals which I can easily obtain.
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Pulverulescent
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─ woelen, have you considered the electrolytic route, at all?
The only real expense is the Pt/LD anode for the perchlorate-cell . . .
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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woelen
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I made chlorates by electrolytic means, using an MMO anode, but making perchlorates is beyond my reach at the moment. I am considering making a PbO2
coating on MMO, but I feel uncomfortable about risking one of my precious MMO anodes for this experiment. So, for the time being I'll continue
research in the direction of oxidizing ammonium ions with volatile oxidizers, which can be boiled away.
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dann2
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You could always make Sodium Perchlorate via Ammonium Perchlorate + Sodium Carbonate. Mix and boil and all the Ammonia and Carbonate will go away (at
least I think it will?)
Then it's acid via the normal route.
Dann2
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woelen
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Dann2, thanks for your hint! Stupid me, that I did not think of such a way myself  .
Instead of Na2CO3 I'll use NaOH. The latter can be purchased over here at better than 99% purity (the rest being water and NaCl). With this I can
indeed make NaClO4 and through that I can precipitate NaCl and make nearly pure HClO4 with only small amounts of NaClO4 left. I'll try this next
weekend.
Probably I need to use a slight excess of NaOH, in order to be sure that all NH3 is driven off. A slight excess of Na(+) ions will be precipitated
with 37% HCl.
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quicksilver
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I have also made chlorate from MMO / Ti via electrolytic tank. The problem with Perchlorates is that the actual "pay-off" is generally not worth the
investment. There IS a thread discussing the application of PbO2 via a "baked on surfacing but remember that oven may become lead contaminated so that
even with a low-cost technique you would have to sacrifice an oven. The other concepts of using a epoxy coat PbO2 doesn't expose enough PbO2 and
pulling the PBO barriers from a lead-acid battery doesn't function well as the barrier is a thin plastic that simply can't stand up to much current.
Generally speaking current levels would need to be at least 3amp @ 5Vdc for any volume. I imagine you could get it lower but it would take a seriously
long time to form up from your salt solution. This is a very nice site set up by some foks who have been working with electrolytic tanks for a long
time:
http://oxidizing.110mb.com/chlorate/chlorate.html
There is a great deal of information there that comes from industrial sources. Perchlorates CAN be made via such a tank but the issue of if it's
really worth the level of commitment is questionable. I have gone as far as a sealed 5gal bucket and some various anodes / cathodes with two serious
commercial power supplies and unless you can get the items for surplus or at a heavy discount; it can get very expensive.
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woelen
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I agree with quicksilver. For me it is fairly easy to obtain KClO4 (app. EUR 10 per kg) and NH4ClO4 at a price tag of around EUR 25 per kg. One kg
goes a long way for me, because I do no pyrotechnics (and then KClO4 is not interesting at all). All the investments of electrodes, huge power
supplies, a suitable tank which can withstand the corrosive conditions of a hot cell and all the hassle are not something which makes me feel happy.
Making a chlorate cell is a nice experiment for the home chemist and can be done at very moderate cost, but a perchlorate cell is another matter. Only
if you are planning to make a LOT of perchlorate for pyrotechnics purposes, then it may be worth the effort. Another reason may be if you absolutely
cannot buy any perchlorates.
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Pulverulescent
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| Quote: | | Dann2, thanks for your hint! Stupid me, that I did not think of such a way myself. |
Facepalm here too . . . ()
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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Rosco Bodine
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Maybe try a half scale experiment in the same two liter flask and use a cold finger or a reflux condenser. There must be a loss of the volatile acid
reactants rather than the loss of volatile byproducts which would explain why the reaction desired is not proceeding and you are being left unreacted
starting solid material because
it didn't have the required contact time and reaction conditions.
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