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dann2
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Perchlorate manufacture (not) with Graphite
Hello,
I cranked up a Perchlorate cell some time ago using a Graphite anode. I put the results up here
http://www.geocities.com/CapeCanaveral/Campus/5361/basechem....
It is in the Graphite anode section.
The long and the short of it is this:
Cell was run for twice the 'run time'.
Current density on anode was 30 to 40mA per cm squared.
Anode wore at a rate of approx. 0.19 grams per Ah run through it.
Bugger all Perchlorate formed.
The electrolyte contained about 2% weight Chloride at the start. THis is the best I was willing to achieve by recrystallizing Home producted Chlorate.
No Perchlorate for 55 hours.
When cell was 'finished' I was unable to extract any usable Perchlorate by adding KCl. Only Chlorate or perhaps Chlorate containing small amounts of
Perchlorate precipitated.
I do not believe that increasing/decreasing current density on Anode, using a different cell temperature, electrode arragement, additives etc etc will
transform the operation of the cell.
Making Perchlorate with a Graphite anode is a HOPELESS
operation IMHO.
OH, did I mention the black mess
Dann2
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Rosco Bodine
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Isn't that a way lower current density than Mad Hatter was using ? I'd have to go back and check and find it , but it seems like he was using maybe
five times that current density or more . Maybe there is a sweet spot
for the current density and you didn't find it .
IIRC , for each anode or cathode reaction there is an
optimum current density . How badly the efficiency drops off when you get away from that figure I'm not sure .....
but from your experiment it looks like it could drop the efficiency a good bit 
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dann2
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| Quote: | Originally posted by Rosco Bodine
Isn't that a way lower current density than Mad Hatter was using ? I'd have to go back and check and find it , but it seems like he was using maybe
five times that current density or more . Maybe there is a sweet spot
for the current density and you didn't find it .
IIRC , for each anode or cathode reaction there is an
optimum current density . How badly the efficiency drops off when you get away from that figure I'm not sure .....
but from your experiment it looks like it could drop the efficiency a good bit
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Hello,
There is no sweet spot IMHO.
The current density that MadHater was using was 200mA per square cm. (Up and kicking with Lead Dioxide)
The graphite would get eaten as quick as you could carry goughing rods (what maDhatter use) to the cell.
Cheers,
Dann2
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Rosco Bodine
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So.... if we don't really want any perchlorate to form , then
we should use 30-40 ma per square cm . But on the other hand if we want the perchlorate cell to actually
make any perchlorate then we should use 200 ma per square cm ?
It would seem that getting some perchlorate along with
eaten anodes would be sweeter than getting no perchlorate along with eaten anodes .
Maybe at 30-40 ma current density , all you have is a bath warmer / anode eroder , and not a perchlorate cell at all .
If MadHatter was getting a good yield at 200 ma current density , then why do you pass judgement before you try
that same current density to see if your results track with his ?
I would bet good money that current density does matter and there most definitely is a sweet spot for each particular anode material , a niche value
that is ideal .
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hashashan
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You should also try to make this with normal graphite and not gauging rods.
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hashashan
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| Quote: | Originally posted by hashashan
You should also try to make this with normal graphite and not gauging rods. |
sorry didnt notice you did use normal graphite,
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MadHatter
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Electrolysis Procedure
This is the electrolysis section of the method I found years ago for making KClO4
using gouging rods. Yes, I eroded a couple of rods because I prefer a higher current
density but I got the KClO4 I wanted. Before I bought a variable power supply, I
used a 6 volt/15 amp battery charger that worked very well. The linseed oil soaking of
gouging rods and keeping cell temperature below 40 C slowed the rate of erosion.
What really caught my attention about the procedure was that the chlorine produced at the
gouging rod bubbles up directly to mix with the potassium hydroxide produced at the
cathode. One improvement I made on the cathode was to spray paint the upper side so
that potassium hydroxide is formed on the bottom side only. The corrosive nature of the
cell will eventually remove the paint but for the most part keeps the electrode products
in very close contact.
BTW, I electrolyse KCl directly bypassing the NaCl route. I don't want sodium cations
contaminating the final product. After electrolysis, add water and boil until the K salts
are dissolved. Filter hot through several layers of white paper towels. This traps
the carbon, paint, and any other insoluble materials.
I use this method because it works for me and gouging rods are cheap.
Electrolysis
Using a coffee can for a source of steel, cut it out to form an inverted U shaped trough. Insert it in the mixture of salt and KCl dissolved in water.
The (-) connector is connected to the steel. The steel U trough (similar to a rain gutter, except upside down) is setting at an angle to increase the
amount of surface area in contact with the liquid. The carbon rod has some aluminum foil wrapped around the end of the rod, and the (+) connector is
connected to it. The rod is positioned within the U shaped trough - under it, without touching. The charger is turned on, and he position & depth
of the rod is adjusted to get 8 to 12 amps of current.
NOTE: A setup with the electrodes running electricity through an electrolyte is called a "Cell". This setup is commonly refered to as a cell
throughout this description.
Let the liquid electrolyze for about 5 days continuously. Add water to make up for water lost during the process, and try to keep it roughly constant.
A couple times a day, you will need to check the current level, and adjust the rod position to keep the current in the 8-12amp range. Mine has been
running between 40 - 50C, but commercial proceedures keep the temp just below 40C to reduce carbon rod errosion. The rods will gradually errode away,
but if you use a 6V charger, one rod will probably last for the full 5 days.
You can also use higher voltage chargers, but you will probably need to connect several electrolytic cells together to keep the voltage accross ONE
cell to be about 6 volts. If you use a 12 V charger, you will need 2 cells ( 12V/(6V per cell) = 2cells). If you connect more than 1 cell in series,
you may need to use a voltmeter to check the actual voltage accross each cell - because it will change depending upon the resistance differences
between the cells, which can be adjusted by re-positioning the rods.
The purpose for the U shaped trough cathode (-) electrode, is to cause the gas bubbles formed to generate a convection flow up through the trough.
This causes the chemical products produced at each electrode to mix and react efficiently. Other electrode geometries will work, some better, and
others worse. The key is to cause the two electrodes to be very close to each other, and cause the chemical products to mix well to help form chlorate
and perchlorates. The WORST case situation is where the electrodes are on opposite sides of the cell, causing the chlorine gas produced at the anode
(+) to tend to bubble and escape out of solution into the air.
From opening of NCIS New Orleans - It goes a BOOM ! BOOM ! BOOM ! MUHAHAHAHAHAHAHA !
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hashashan
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How did you make perch from K-chlorate??? its really poorly soulable only 7gr/100ml, what was the temperature of the cell?
How well did you clean off the chloride and how?
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dann2
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Hello MadHatter and folks,
Glad you came in.
I don't want to annoy/insult/sound-like-a-complete-prick but here goes.... Drumm rollllll.
The procedure that you have read on the Internet for how to make Chlorate + Perchlorate (or Perchlorate) is:
*COMPLETE AND TOTAL CRAP*
The site that (I believe) you are quoting from is an old site
put up by a guy studying electrochemistry back in the ninties.
The guy has since gone on to graduate etc etc but the information regarding Perchlorate making on his page is NOT correct.
He himself had lost access to the page (left university) and could not correct it. The method he used to identify the 'Perchlorate' was the fact that
he was getting lovely glinting crystals of Potassium 'Perchlorate'.
At run times before the glinting 'Perchlorate' appeared the observed crystallization was not of a pretty glinting variety. Thats because the early
crystallizations were a mixture of KCl + some K Chlorate. He thought this was Chlorate----> then on to Glinting 'Perchlorate' later.
The lovely glinting crystals are pure Potassium Chlorate.
You will not get any Perchlorate worth talking about from this method. You cannot make Perchlorate in any sensible manner using a Graphite anode,
PERIOD.
It has the added danger that people think/insist they have Perchlorate + combustable when in fact they have a mixtrure of Chlorate + combustable when
they go to use it.
(Though K Chlorate is not a dangerous as Sodium Chlorate, it is not wise using a Chlorate when you think you have a Perchlorate).
There is a last remnant of the page you quote from here:
[Go to the second link down the page just below the yellow bar] Note the bold writing at the top.
http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/...
The run time table was taken from the page you quote. It was the first page ever on the internet explaining Chlorate making (Gouging rods and
Graphite, some mention Pt). It was early days back then. Wouter Visser was in the same group so I am not trying to say they were clueless. The info
for Perchlorate was simply wrong.
The link at the very bottom of the page below was put there in an attempt to stop people assuming they have Perchlorate (whether or not they are
using Lead Dioxide, Platinum (or God forbid) carbon) when the cell is in fact still a 100% Chlorate cell. NO PERCHLORATE.
http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/...
As Hashashan pointed out (as well), it is not feasible to manufacture Potassium Perchlorate from Potassium Chlorate as the solubility of K Chlorate
is too low for to obtain a sensible concentration of it in the cell.
If you have any of the 'Perchlorate' left, mix it with some sugar (50/50) and put a drop of concentrated sulphuric acid on it. It WILL ignite.
Mind you fingers (and more!) if using Sulphur etc.
Dann2
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Rosco Bodine
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Graphite and Carbon Anodes
Some reading through old patents tells me that indeed
carbon and graphite anodes of some type have most
definitely been used successfully for perchlorate production
in specially designed cells . And there are references griping about the difficulty , and the erosion , and having to interrupt production to clean
out the graphite sludge from
*perchlorate* cells . And there are a few references which
mention use of "activated" graphite in such cells , but exactly what is "activated" graphite is unspecified .
I found one single patent that illustrates the use of a graphite anode in a perchlorate cell , and it is a divided cell .
And I found one patent which seems to describe what might be the idea of an "activated" graphite , but I am not certain this is the same thing .
Attachment: US1279593 Perchlorates Using Carbon Anode.pdf (173kB)
This file has been downloaded 808 times
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Rosco Bodine
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"Activated" ???? Graphite
Maybe something similar to this is what is meant by
activated graphite . Evidently graphite can be glazed
with a conductive doped alumina baked on at a moderate
temperature to improve its durability .
Attachment: US3377265 PbO2 doped alumina anode coating.pdf (326kB)
This file has been downloaded 792 times
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dann2
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| Quote: | Originally posted by Rosco Bodine
Some reading through old patents tells me that indeed
carbon and graphite anodes of some type have most
definitely been used successfully for perchlorate production
in specially designed cells . And there are references griping about the difficulty , and the erosion , and having to interrupt production to clean
out the graphite sludge from
*perchlorate* cells . And there are a few references which
mention use of "activated" graphite in such cells , but exactly what is "activated" graphite is unspecified .
I found one single patent that illustrates the use of a graphite anode in a perchlorate cell , and it is a divided cell .
And I found one patent which seems to describe what might be the idea of an "activated" graphite , but I am not certain this is the same thing .
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Hello Rosco,
I'll be dammed!
Perhaps there is hope and redemption for humble down trodden Graphite in the production of Perchlorate after all. 
Will read patent.
Another angle for getting Graphite to product Perchlorte may be to start with Lithium Chloride (or Chlorate). According to a source I read, Lithium
Chloride converts very easily from the Chlorate onto the Perchlorate (Using Pt or Lead Dioxide).
Perhaps it will convert fairly easily using Graphite anode.....perhaps not.
The reason given for Lithium Chloride converting easily into Chlorate------->Perchlorate was because of the small atomic radi of the Lithium ion.
This explanation does not make sense to me because the Lithium ion (or Na or K) is only a spectator ion in the Chlorate/Perchlorate making process
AFAIK.
Lithium does not introduce a yellow interfering colour into pyro mixtures if you go on to make K. Chlorate or K. Perchlorate.
BTW I have been running the Graphite anode cell at a higher current density just to make sure the old horse in well and truly dead.
I do not believe it will make a jot of difference to Perchlorate yield ie. still effectively zero for all intents and purposes.
Dann2
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Rosco Bodine
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Yeah I am a bit doubtful about the graphite anode myself , and it seems like I recall some additive , perhaps dichromate was absolutely required to
prevent a competing reaction on the cathode where perchlorate was reduced right back to chlorate as it formed ....possibly why the requirement for a
divided cell described in the patent .
Anyway I have been looking at other anode materials and mostly only considering graphite for substrates or for cathodes . I'm so cheap I don't even
like the idea of
corroding graphite , aside from the messy sludge it makes .
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garage chemist
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Why try so hard making perchlorate electrolytically, if its so hard to find a good anode for this just make chlorate with graphite or MMO and
thermally decompose it.
If I had time I could document and post the procedure of how I made KClO4 from NaClO3. Is there even interest in this oldest and first ever used
method of obtaining perchlorates?
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12AX7
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It's been explored in another thread. As I recall, it's a load of crap, i.e. not very successful at all. Takes precise temperature, pure reagents
(including the crucible, which must be tolerant of a strong oxidizer and molten salt) and long times to give low yields.
Tim
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jpsmith123
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Garage Chemist are you still toying with the idea of trying to make a PdO based MMO anode?
I think that is one unexplored area that could potentially be very useful.
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garage chemist
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Yes, MMO anode is one of my projects, I have bought two strips of grade 1 titanium sheet from ebay which are yet to arrive.
PdO will be my first experiment, and then RuO2/TiO2 coating as in Beer's patents. TiCl4 will soon be ordered, as will Ru powder. Also, synthesis
instructions for titanium tetrabutylate must be acquired.
Thermal decomposition of chlorate is NOT a load of crap, I had very good success with it, and the crucible can simply be a small beaker since glass is
suitable as the container.
The correct temperature can be judged by the gas evolution, a thermometer is not necessary.
The chlorate only has to be free from heavy metals, while chloride impurity is no problem since the reaction produces chloride as side product anyway.
50% yield is easy to obtain in 2 hours reaction time.
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jpsmith123
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I'm surprised that you're so strongly against the idea of a PdO/TiO2 mixture. Is this simply because there are no specific examples of this mixture in
the patents, or is there a theoretical reason you're opposed?
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12AX7
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Really, I recalled differently from that thread.
Ah well!
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garage chemist
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Did I say I was against a PdO/TiO2 mixture? The reason that I am not considering it is that i have found no patents that use it.
Also, RuO2 and TiO2 have similar crystal structures which enables them to form mixed crystals (read it on a link on dann2's site) which is the reason
that RuO2/TiO2 coating is more resistant than any other MMO coating.
I suspect that PdO and TiO2 will not be able to form mixed crystals, which would make PdO/TiO2 even less resistant than pure PdO.
Whenever PdO was used as MMO coating in mixture with something else, it was with Tantalum oxide. Those probably form mixed crystals.
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jpsmith123
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Well you clearly implied you were against it. And I was trying to understand your reasoning. If you have all the materials necessary to test it, and
you say you don't intend to test it, I figured there must be a strong reason why. Especially since it seems that the PGM oxides *by themselves* are
not very robust.
The Japanese patents I cited before state or imply that PdO doesn't work very well by itself...it doesn't stick well to Ti. And Beer's patent 3632498
says basically the same thing (about all the PGM oxides including PdO). Then on page 4 it says:
"The problem of rendering the oxides of the noble metals and other metals in finally divided condition adhesive and at the same time resistant is now
solved by virtue of the co-precipitation of the non-film-forming conductors with the oxides of the film-forming metals. It is surprising for example
that palladium oxide, platinum oxide and ruthenium oxide are then fully resistant." (Note Beer specifically mentions PdO as being "fully resistant"
when co-precipitated with a film-forming oxide).
Then on the same page of the patent the table shows Pd/Ti co-precipitated oxides as being qualitatively the same as the other MMO compounds.
And finally there is an example in the patent of a PdO based MMO, and that is example VII (it is not TiO2 but TaO2).
So as I see it, if you just try to put PdO on by itself, you will likely be wasting your Pd, whereas if it goes on with TiO2, you will likely end up
with a useable anode that may make ClO4 and ClO3.
And I don't want to see you waste your Pd and leave the ClO4 question unanswered.
[Edited on by jpsmith123]
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garage chemist
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Alright, you proved my theory wrong, I admit.
I havent read the patent you cited until now (or atleast not thoroughly enough).
I have only started reading up on the whole MMO thing very recently, and surely still have something to learn.
A Pd based MMO anode which is as resistant as a Ru based one would be optimal- Pd is both cheaper and easier to get and work with than Ru.
When my titanium arrives and I start experimenting with MMO coatings I will open a thread exclusively on homebrew MMO anodes. I hope this to be more
successful than the PbO2 anodes, which nobody has gotten to work satisfactorily AFAIK.
[Edited on 8-6-2007 by garage chemist]
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jpsmith123
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"A Pd based MMO anode which is as resistant as a Ru based one would be optimal- Pd is both cheaper and easier to get and work with than Ru."
Exactly! And according to the narrative in one of the Japanese patents, it may have much better catalytic properties than Ru. If this is true, I would
expect higher efficiency in a ClO3 cell, and the possibility to make ClO4.
I've got everything I need to try it also. I just have to get out of this tiny little apartment I'm in and get my workplace set up again. I got some
0.032" CP titanium sheet from ebay a while ago which I cut into 2" x 8" strips all set to go.
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garage chemist
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Ah, time is my problem, I'm stuck in this small apartment during the week at the town where I'm studying, and can only drive home (2 hours) to my lab
every weekend. This is really limiting any experiments I can do.
Could you write down your japanese patent numbers again? That would be nice. I havent seen them in the other thread.
My titanium sheet is 3mm thick, which probably is excessive, but I have seen current densities of up to 8000 Ampere/m^2 be used in some of the
patents, which is 800 mA /cm^2 if I calculated correctly. This is an extremely high current density. I didnt even use such high current densities with
my Pt wire anode in my perchlorate cell.
My objective is to make an MMO anode which only produces chlorate, though. I can clearly see why industry keeps chlorate and perchlorate production
strictly apart- it simply is way more economic to keep the stress of the initial chlorate production away from your precious ClO4- capable anode.
MMO anodes will OWN the disgustingly messy PbO2 bullshit!!! 
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dann2
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Higher current density
Hello,
For all (if any) doubters I ran a quarter liter of the cell solution
(extracted from above the black sludge) for a further 264 Ampher Hours at
a current density of between 120 and 220 mA per square cm.
(Graphite anode of course.)
Density varied as
the anode wore.
The liquid (at the top of the black sludge) after settling was still a
very black colour, blacker than the first run. The sludge made up most of
the cell contents.
I added a small quantity of dilute KCl solution and got a ppt. This time
the ppt looked more like Perchlorate as the crystals did not glint.
I washed the ppt four times.
Dried and mixed (50/50) with sugar.
A drop of Sulphuric caused instant ignition.
I have either Chlorate with Perchlorate contamination or Perchlorate
with Chlorate contamination or whatever you like to call it.
It should be noted that a total of approx. 500 Amper Hours per mole
Chlorate has passed through this solution.
(A total of approx. 60 Ampher Hours would be the amount needed to convert
one mole Chlorate into Perchlorate at 100% current efficiency.)
No usable Perchlorate can be extracted using KCl as the 'extractor'.
BTW the concentrated sulphuric acid test is a quick and easy test for the
presence of Chlorate with combustable.
I tried it with pure K Perchlorate + sugar (50/50) and got no ignition.
Fineto Fin Finish End of Perchlorate with Graphite thread.
Alembic (posted here) has made a successful Ti substrate anode. He too has made successful GSLD Anode way way back in antiquity .
The Lead Dioxide is two things.
1) The poor man's Platinum
2) The lazy man's Platinum
Cheap (if you can get it to work) and lazy as you plonk it in a Chloride solution and come back and extract nearly pure Perchlorate.
What makes you guys think that MMO will make Perchlorate?
Have you seen it anywhere?
The Platinum based pool chlorinator anode (posted on this site by Joe) was said to be Platinum based by a guy who seems to work with such anodes. When
he said that it was Pt based he meant Pt metal, not oxides of Pt. It was black Platinum which is a form of Pt metal that deposites under certain
plating conditions. (Perhaps it containes some Pt Oxide but it is (surly) the Pt metal that is/was making the Perchlorate.
Regarding the thermal decomposition route there is a patent (on my site?? I think) that explaines the process in detail.
As far as I can recall you need to keep the temp. between 400 and 420C for a fairly long period of time (approx. 24 hours) Easy enough if you have a
temp. controlled device I guess.
As far as the Perchlorate with Graphite thing is concerned it was just something that I wanted to put to rest one way or the other for once and for
all. The description of u shaped cathodes with Graphite anode is still sitting out there in usenet. It sounds very simple and convincing.
Dann2
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