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Author: Subject: Thoughts On Anodes
Arcuritech
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[*] posted on 22-8-2012 at 19:19


What about metallic crystalline Boron? Silicon was mentioned in the first post, and that also might work. Fortunately for me I have both of these things, I'll have to test them out next time I'm in my lab.



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White Yeti
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[*] posted on 28-8-2012 at 08:14


What about using polythiazyl as an anode material? This has already been discussed in several small threads that I will not cite. But discussion has died down very quickly, perhaps because of the dangers associated with making and handling S2Cl2. I would like to present a different synthesis route for S4N4 (the precursor to polythiazyl) involving liquid ammonia and solid sulfur instead of S2Cl2 and gaseous ammonia:
10S(s) + 4NH3(l) —→ N4S4(s)+ 6H2S(g)
Source:
Handbook of Inorganic Chemicals by Pradyot Patnaik

The S4N4 can then be reacted over silver metal to yield its polymer.

Does anyone have information on the electrical conductivity of this polymer and/or its chemical inertness?




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elementcollector1
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[*] posted on 29-8-2012 at 21:35


I have something interesting to contribute, and I WILL share it with you!
While electrodepositing manganese metal from it's aqueous chloride, I noticed that if too much current is applied to the solution, or only one cell of electrolysis is used, the cathode will receive a firm, strong deposit of MnO2, resistant to flaking and such. Chlorate anode? We'll see.

It wasn't exactly what I wanted at the time, but I thought it might be useful to you.




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[*] posted on 22-10-2012 at 08:41


I have recently come to interest in this type of anode, and while exploring the "ironage" iron mine near twenty nine palms, ca. I now have some very large massive chunks of hydrothermal generated natural magnitite, and a few small slabs of very well formed massive crystals hammered off a monolythic rock the size of a car. I currently looking for someone that has a diamode saw with a feeder co I can cut some nice slabs, considering that I have an unlimited source of this material it has not peaked my inteast, also iron mines are very common, I bet a lot of ppl live within reasonable distance fro one to pluck chunk of out magnatite of a near by wash. Just an idea.
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[*] posted on 30-11-2012 at 06:54


JPSmith, have you pursued the Bi Pyrochlore at all that you posted on page 40 (Aug 2011)?

I have been re-reading those patents, and I think there's some potential, even if it involves Ru.

RuCl3 hydrate can be had for moderate prices... I was quoted $8 per gram from one Chinese source. I did manage to pick up 25 grams of the chemical.

I'm wondering if the pyrochlore configuration is necessary for success with perchlorates. I suspect it does, but I am tempted to simply modify a Beer procedure with the addition of Bismuth.

As I mentioned in another thread, I am gearing up for a massive effort in MMO creation. I have prepared Ti strips, and gathered up a list of reagents:

Bi(OH)3
RuCl3
T-butanol
PdCl2
SnCl3
MnSO4

And the necessary mineral acids to make it all hopefully work. I have a good furnace that can do 1100C if needed, although all of the Beer patents use a much lower temperature.

Both Bi(OH)3 and RuCl3 can be easily turned into the appropriate oxides per the pyrochlore patent, but the obvious question is how can this material be attached to a valve metal with any success.

I wonder if Bi ions, if added to the typical Beer "paint", then fired at extreme temps, would form a pyrochlore or some sort of solid solution which would be catalytic to oxygen and perchlorate.
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[*] posted on 30-11-2012 at 07:55


I may have mentioned, I am working on a document regarding electrochemistry as applied to chlorate, perchlorate, lead dioxide plating, etc., trying to gather together into one place as much knowledge and practical experience as possible. It's over 200 pages now, but not yet complete due to lack of practical perchlorate processes that don't use Pt.

Anyway, one of the things I did was create worksheets for two of the most common questions a beginner has...

1) How long do I run my cell?
2) What was my CE (Current efficiency)

They are based upon KCl. The numbers need to be switched up a bit for NaCl.

There was a guy on another forum who had some questions on this and I created a separate download with these worksheets. Maybe some guys will find them useful.

Worksheets
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elementcollector1
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[*] posted on 30-11-2012 at 19:35


Ooh, I want that 200-page report! Would be incredibly helpful, as I'm just starting on my journey of producing perchlorate (I have a small platinum wire as an anode).
Both of those questions you mentioned are always vexing to me, I would love to see them answered!




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[*] posted on 1-12-2012 at 07:10


Download them! There is a link in my post.

Here it is again... Length of Run and Current Efficiency (KClO3) Worksheets

Note again this is for KCl electrolysis. Until you know your efficiency, you have to estimate for the length of run. If you are executing quality pH control, and maintain close to 6.8, then your efficiency might be 80 or higher. With NO pH control, efficiency is probably close to 50%.

Efficiency drops as chloride concentration decreases. I've noted with MMO at least that below about 5% chloride, efficiency drops dramatically.

A saturated solution of KCl at typical ambient temperature is about 15% to 16%, so use that as a starting percentage unless you heat your solution to dissolve more KCl. So a typical run would go from 16% to 6% chloride.

Some excerpts:

For no pH control and an estimated 50% efficiency, using conservative ending chloride %


Quote:

Extremely basic Run-Time Rule of Thumb for a cell operating at 50% efficiency:

Ampere-hours = Cell Volume (Liters) * 360


Quote:

Predicted yield: Regardless of the CE of your cell, there is a simple rule of thumb for the approximate yield from a potassium chlorate cell. As mentioned, and reproduced here for your convenience, for a given liter of electrolyte, each incremental reduction of chloride by 1% (i.e. 12% Cl- to 11% Cl-) will yield 35.7 grams of KClO3. A typical cell, run from 14% Cl- to 8% Cl- should yield ~214 grams per liter of potassium chlorate. Ten liters, therefore, yields 2,140 grams; 2.14 kg. The dry weight will be somewhat less, as much of the KClO3 will remain in the used liquor for recycling into the next run.


If you are running a sodium cell, ignore everything I've said. Ampere-hour requirements for sodium chloride are different, and there is no solid to be harvested until the liquor is displaced with KCl.

It's controversial... many prefer sodium because it is more soluble than potassium, but I want no sodium ions in my product, and I find that being able to harvest crystals directly from the cell to be a benefit. Lack of solubility can be made up for with cell volume. As noted, you can harvest several kilograms from a 25 liter cell. Given a good wash, the product will be about 99% KClO3, and 1% KCl. If you need better than that, KClO3 is easily recrystallized.
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[*] posted on 3-12-2012 at 18:09


Hey, quick question: I have a tiny 1" Pt wire that I'm thinking of using as an anode, but I'm concerned about the difference in size to it and another cathode, and how this will affect cell efficiency. So, given that I plan on using a stainless-steel spoon as cathode, should I use a spoon-sized MMO-titanium anode or the wire-sized Pt anode? I can make an MMO anode if that's what I need, but if platinum wire works just as well, I don't see why I should bother.



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[*] posted on 5-12-2012 at 08:36


IMO, cell efficiency is the least of your worries. The effective surface area of your wire is going to be very, very small. I assume you are doing a small benchtop setup for fun, because you are not going to get much product, mass wise, unless you allow the reaction to run a LONG time.

Pt will oxidize Cl- ions all the way to perchlorate, ClO4- but most of the time, it is reserved for only the chlorate (ClO3-) to perchlorate (ClO4-) process, because chloride ion does indeed erode Pt. So does the chlorate --> perchlorate path, just slower.

Your current is going to be, must be, very small with an anode that size. 200 mA per square centimeter would be appropriate. Too much current, and you are going to lose that Pt. For a cathode, your best bet would be a piece of titanium or stainless steel wire. If you don't have those, look for a long, thin, stainless wood screw at the hardware store. Or... use the spoon. Current density on the cathode isn't as important as the CD at the anode.

Applying current to such a tiny piece of wire is going to be tricky. The connection, unless you weld the wire, probably needs to be above the electrolyte level, losing still more anode surface area.
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[*] posted on 1-6-2013 at 08:13


I apologise for bringing up an old thread, but I had an idea for a potential anode material.

What about using a titanium electrode coated in titanium disulfide (TiS2) as an anode in a chlorate cell?

One weakness of this electrode would be operation in acidic medium. From memory, a chlorate cell operates best at pH 6, so this should not be a significant problem.

Titanium (much like lead) cannot be oxidised past +IV, so this electrode material should hold up to a highly oxidising environment.

Does anyone think this idea is plausible? I would try this myself if I had a suitable furnace.




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[*] posted on 2-6-2013 at 10:08


Where it is used, I never heard about such anode?
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[*] posted on 3-6-2013 at 12:00


The point of experimentalism is to try new things based on plausible ideas.

PbO2 anodes, MMO anodes, and platinum anodes have been beaten to death, it's time for something new, anything new, even if it may end up being wrong.

I hypothesize that if an etched titanium electrode is heated in a suitable* furnace in the presence of sulfur during a suitable* length of time, the resulting titanium-sulfide-on-titanium-electrode would be both conductive enough* and resistant enough* to be used in a chlorate cell.

*experiments are needed to determine these parameters.




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[*] posted on 3-6-2013 at 12:48


Completely agree with you White Yeti, I just said that I never have heard about that compound in the past (and also it's electrical properties). Another things that may be ''new'' is TiN - golden coating on some instruments, it's also conductive and all you need is Ti+N2 reaction (in powdered form it's quite an exothermic reaction, so SHS synthesis is possible(available?) on this), but I highly suspect it's not inert enough to work as an anode in brine.
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[*] posted on 6-6-2013 at 18:16


Titanium nitride could be a viable alternative, although I wonder if it would be truly impervious to flaking and oxidation. Then again, there is no way to tell whether or not an anode material is susceptible to flaking during operation.

Now that I think about it, a TiS2 anode could be susceptible to flaking as well...




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[*] posted on 7-6-2013 at 06:37


Only two ways from that point: trying to find out related information or the experiment must be carried out. Search in this forum (maybe even in this thread), there I've seen once a paper (some ''top secret'' of the past) which contained info on TiC, etc, etc.. (I couldn't find now to provide link).
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[*] posted on 30-7-2013 at 06:22


Somebody knows where you can buy graphite sheets to use as anodes. I have googled it, and searched on ebay, but i havent found anything.

Have a great day, guys!
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[*] posted on 30-7-2013 at 12:02


batsman - clearly you didn't try very hard!

Several years ago, I bought graphite anodes from the Graphite Store! The freight to NZ was more than the cost of the graphite, but the product and range was good as were their prices.

http://www.graphitestore.com/
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[*] posted on 11-10-2014 at 01:46


nothing really new I guess, but I made a crappy spot welder and tacked some titanium wire to both mesh MMO and plain sheet, as a resistant support for the working plates. I haven't even finished the spot welder yet, used a rubber mallet to hold down the floating electrode and moderated power with turning on and off the power strip it was plugged into. super ghetto I know, but I just wanted to see if it could be done on an "I don't have all the time in the world" mock up, with improvements to come. I have a variac I'm not using yet, as well as all the materials to make a nice one with variable power. but for now here are some pics

IMAG1338.jpg - 869kB IMAG1332.jpg - 883kB IMAG1333.jpg - 1000kB IMAG1335.jpg - 832kB IMAG1337.jpg - 1.1MB

1)you can see the size wire I used for the 1-1/2 wrap
2) front of the transformer
3) tacks on plate and two mesh MMO pieces
4) close up of the spots
5) another close up

they seem physically OK, not super strong, but short of TRYING to tear them off the Ti wire wasn't going any where. survived 3 increasing tweaks with out snapping. how they perform chemically is another thing. I only flattened out an edge on one of the wires, which mean the other two have less surface area meeting, which was also really hot in standard atmosphere ( no O2/N2 shield of any kind used ) so it may make a nifty lill cave for gas generation from weakened titanium, may be fine.

on my first try with two wire pieces, it got hot, then blew out. after cooling it looked like the heart of the two wires shot out through two volcanic craters ( tiny ones, but half the depth of the wire)

fun learning experience, now it's time to make a sweet lever arm to reliably spotweld. .... and figure out how to bend the Ti plate at a 90'<, every time I do it snaps just prior to 90'. but I wanted to make support strips similar to what is seen in a pool electrode stack. because I am actually trying to use this for my pool.

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[*] posted on 11-10-2014 at 03:40


You need expanded mesh titanium. It takes to being bent better than solid sheet. I've gotten right at 330 degrees without it breaking.

Superscripts don't seem to be working.



Little Ghost, Look at his MMO mesh. You should be getting 2 pieces
of the same size in the Post shortly.

[Edited on 11-10-2014 by hyfalcon]

[Edited on 11-10-2014 by hyfalcon]
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[*] posted on 11-10-2014 at 05:27


I had looked for the bare titanium mesh, but couldn't find any in my price range for this project. probably would have had a hard time ordering such a small amount as well.

what I ended up getting 2 @ 6.75" x 10" MMO mesh from laserred, and 8 @ 3.125" x 8" x 1/16th plate from ebay. I also have a dwindling supply of ~3mm wire welder Ti purchased a few years back( soo many electrodes were made). the metal is a bit tough on tools, I'm not set up with a metal working shop. that was immediately apparent. I purchased more than I need, so several attempts could be made. some of the plate is to be cut up for support of the small stack that will be built.

but I am quite pleased with the spotwelder capability, and have already cut and drilled two steel pieces for the electrodes as support plates for the copper so I can apply some force with a lever. it gets hot quick and increased force will allow for a stronger bond with less discoloration, from what I am seeing. as it is, I was using multiple quick 1-2 sec heating. at least the oxidation stayed localized. also noted, after messing around with it for 20 min off and on accessing its capabilities, it( the secondary) was only slightly warm and the core was still cold to the touch.
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[*] posted on 10-2-2015 at 14:24


A question about "standard" MMO pool chlorinating anode - recently I got some from very well know *bay seller, but what I got raises few questions to me.
first - it has some rust-colored spots on the surface, also it's not completely dark and has even golden-copper red tint on some sites - is this normal or the anode is already hard-used?
second - I tested it in a NaCL solution at LOW current densities (about 0.5A on 5cm2 and 3.9V) - surprisingly after some time it still works(electrolyzing), but now I have some orange stuff floating on the surface of water, and since the cathode is made of high quality titanium - it comes from MMO anode. I changed the solution with a fresh one - and once again after few hours of electrolysis some orange-brown stuff is floating on top! Is this anode wearing out or what? I thought MMO is really rough stuff, what is going on???
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[*] posted on 10-2-2015 at 14:38


Sounds like iron(iii) oxide. Are you sure the MMO substrate is Ti for your anode? I would suggest testing your crud for iron.



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[*] posted on 10-2-2015 at 14:52


The substrate stays unaffected since I can see from sides (where it was cut) - most likely it's titanium, magnet doesn't act on it. So far I don't see any major damage also to coating, but that brownish crap collecting on the top makes me think it's degrading!:mad:
Coating must be RuO2 based, not something like Co oxide, isn't it? In the past I was experimenting with self-made Ti/Co3O4 anodes, which were not very stable and were degrading like this (if it's really degrading)one giving out floating stuff, is it possible that I got Co3O4 anodes instead of RuO2(do they exist in the market?)?
I just really want to listen to everybody who worked with MMO what they think on this issue, please..
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[*] posted on 11-2-2015 at 00:55


After 12 hours of electrolysis there was not only orange junk floating on top, but also some white fluffy stuff floating in the liquid. Sh*t! After that I started with a fresh NaCL solution third time and already after half hours there's that same orange thing appearing! Of course I don't use distilled water as a solvent - just plain water and table salt, but this cannot be the problem, isn't it? Somebody say something, I'm quite disappointed.
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