KCLO3 by way of H2O + KCL

Hello,
That is a high temperature for Graphite.
Would it be possible to weigh anode every half day to get an idea of wear.
Some nosey git would like to know

Dann2

3.5 kilos, minus what water is still present (no more than 0.5 kg I would guess).

This is the result of a week's run (about half of those days running, due to a shortage of brine), which produced 3 kg of NaClO3. This was dissolved in 1.6 kg boiling H2O and mixed with 2.1 kg KCl dissolved in 4.2 kg boiling water to precipitate the KClO3. Another 0.5 kg or so should be dissolved in the leftover liquid, giving yield around 85%.

And no, I don't really have a use for all this chlorate... Right now my interest is to tweak my process in terms of efficiency, time spent, etc.

Tim

Tim
I thought your PC power supply burned up. Did you get a new one? Hey one thing you can do it get some oxalic acid (Meijers has 2 pound jars near drain openers) and mix with your potassium chlorate to get a uniform crystal mix and then add enough battery acid to submerge. These 3 ingredients do not react intitially at room temperature at least not at perseptable measure anyways. Immerse a test tube of the mix in water above 60 Celcius and you get on-demand chlorine dioxide. Great for water treatment while camping etc.
Don't store ingredients mixed. Make ony what you need. It smells like chlorine AND nitric acid SEXY STUFF

[Edited on 7/24/2007 by chloric1]

[Edited on 7/24/2007 by chloric1]

Ok, thanks. Carbon it is

Well I completed my first 14 day chlorate run about a week ago. My observation conclude that graphite is the best choice. Take note the quality of the carbon you choose is important. I started with a mediocre grade graphite rod and it was destroyed in 6 or 7 days. I now have two shorter pieces of this rod. I switched to a "denser" stronger graphite and the anode only suffered minor pitting. So may recommend EDM grade graphite. It is reasonalbly priced on ebay but expensive everywhere else.

I don't have indigo testing solution so I tested for chlorate by trying to ignite the dried filter paper I used to clarify my electrolyte. WOOSH! Burned so hot that some NaCl vaporized and condensed salt on a near by rod of metal!

I wanted to crystallize sodium chlorate but I ony have 300 grams per Liter more or less. So I will boil down and add more saltwater and rerun for another week to 10 days. This stuff is soluble!!

[Edited on 8/27/2007 by chloric1]

Progess

Well, I was not able to identify any chlorate looking crystals from my first run even though the filter papers burned like slow gun powder. I might have only had 300 grams or 350 grams NaClO3 per liter so I reran at 5.97 AMPS for just under 168 hours and the last 48 hours where without the lid. As Tim says the salt spray is atrociuos but I concentrated the solution down from 2 liters to 1 liter! I think I flipped over the balance and I have NaCLO3 as major constituant and NaCl as a minor one. I have maybe 100 or 150 grams of clear cubic crystals that fell out during filtering. They look like bust glass they are so clear. Unfortunately, they taste much like NaCl. The chlorate is a cooling saline taste simular to the nitrate. I know I am looking for tablet type crystals and I am boiling down to try to affect this. Maybe most of my chloride is out so this should'nt be too hard. I will return the cubes to solution and blend with more saturated NaCl for the next run. I might not crystalize all of the chlorate and put some of the mother liquor back in the cell to give the electrolyte a head start. I will let you know maybe with photos as things progess.

@ Deralt- You know maybe Perchlorate may form at graphite anodes but would anybody want to try? The yields would be poor and after destroying the significant chlorate amount I feel most would be disappointed. Don't worry I have a couple ideas for composite anodes. That is if I ever have free time to make them.

[Edited on 9/8/2007 by chloric1]

I know its not alot but the yellow color is REALLY annoying! Here is my electrolytic urine

[Edited on 9/14/2007 by chloric1]

Precipitation

Barium chloride

I don't know why I did not think of this sooner!
Barium chloride forms very insoluble barium chromate which precipitates and leaves a clear fluid on top. Some barium goes into solution but the remainder seems to drop out during boiling and concentrating. Just be sure to separate this before the solutions cools. Here is the resulting solution after barium treatment. I am waiting for crystallization right now in the freezer.

Since I do this continuously, I remove the material and leave the chrome in place. I have a whole bucket (about 5 gallons) approximately that color.

...That would be a lot of urine...

Tim

Chlorate crystal

OK this my final result. After spending the night in the freezer at 20 below zero Celcius, I got these crystals with peculiar cubic characteristics different than sodium chloride cubes. The cluster in my hand has a notably large cube face so I tried to capture the suns reflection with it for photo drama .

@Tim,
Even with HUGE volumes of crude product like you have, the actual quantity of barium choride would be small in comparison. You may only want to do a few smal batches if you wanted purified chlorate for a specific use or crystal study. Great thing to do next time you have downtime.

[Edited on 9/15/2007 by chloric1]

Nice sample.

I have some crystals like that. None of them as large, but I do have a few which formed over several days which are very clear, and clearly cubic in shape. Remarkably, most of these sorts of crystals are formed in raw yellow solution, yet they are hardly colored.

When rapidly cooling from a boiling, saturated solution, I get a hard bed of stepped, rounded (not quite polygonal) crystals that's hard to break up. (It seems to me a lot of very soluble substances do this.) The difference is probably the temperature of spontaneous seeding and, especially in regards to clear crystals, the cooling rate.

Tim

Quote:

Originally posted by chloric1 OK this my final result. After spending the night in the freezer at 20 below zero Celcius, I got these crystals with peculiar cubic characteristics different than sodium chloride cubes. The cluster in my hand has a notably large cube face so I tried to capture the suns reflection with it for photo drama . [Edited on 9/15/2007 by chloric1]

This is a bit off topic, but sodium chlorate was a popular choice for crystal growing recipes in more enlightened times. It is very easy (like alum) to grow large perfectly formed crystals. Now, if only I could find my crystal growing book (damn kids!) there is a lovely photo showing this!

Edit: Ah! Finally found it! It was in a kitchen cupboard with the crystal growing chemicals! Interestingly they mention that if the growing solution has 6g borax for every 100g chlorate, you can entirely suppress the growth of the cubic faces and the crystal will take on the tetrahedral shape! So perhaps the more cubic shaped your crystals are is an indication of purity.

Regards, Xenoid

[Edited on 15-9-2007 by Xenoid]

I was curious about how much current Pt could handle.

So...anode and cathode both 0.3cmx0.8cm Pt foil. Assuming only the area of the electrodes that are closest together have the majority of current flowing through them, that gives an effective surface area of 0.24cm². 4.5A was run through these electrodes for 6h, the cell stabilized at 85C. Current density=18.75A/cm².

Funny thing is, the electrode that was badly dissolved was the - cathode Which is very odd, it should have been protected from dissolving, any dissolution should have taken place at the anode, which is still perfect. I have looked for all sources of me making an error and confusing the two electrodes, but I took pictures at the beginning, and it was hooked up the way I think, and a voltmeter was attached indicating that my - and + leads were the ones that I thought they were.

How strange.

Now the challenge..cleaning PtO2 off glassware...Hopefully peroxide/HCl works.

[Edited on 22-9-2007 by The_Davster]

According to Dann2's site, 600 mA/cm^2 is considered high by industrial standards for Pt electrodes in a perchlorate cell, that's 6000 A/m^2. Now 18.75 A/ cm^2 that's 187500 Amps/m^2. I'm surprised you had anything left at all!...

Regards, Xenoid

Crystal growing

@ Ciscosdad

It's an oldie! But I've seen some of the "recipes" published on various crystal growing websites.

Crystals and Crystal Growing by Alan Holden & Phylis Singer.
Published by Heinemann, 1st Published Great Britain 1961.

I bought my paperback copy in the mid 60's from Verity Hewitt in Canberra for 13 shillings and 3 pence!

I'm not sure if there are anymore interesting titbits in it, I only noticed the borax reference when I was looking up the NaClO3. It is interesting though, to experiment with growing crystals and deliberately introduce various amounts of ions with the same charge but differing ionic radii so they are incorporated into the lattice but cause distortion and change the growing habit.

There is an appendix with about 10 amateur "research" topics.

EDIT: I just googled it, it is still available. Looks like Phylis got married and is now Phylis Morrison!

Regards, Xenoid

[Edited on 23-9-2007 by Xenoid]

The book!

Power supplies

No.

Just build three cells

Tim

Ah, that should work. As long as the cathodes are widely seperated, they won't be prone to corroding each other.

I prefer using the steel housing as cathode, which obviously wouldn't be very amenable to such a solution

A diode will prevent current backflow (which would otherwise cause the internal regulator to throttle down or cut off, as it does when lightly loaded), but it will not encourage current sharing. A diode has a steep rate of current vs. voltage, little better than the power supplies themselves. To share current, you need each supply to be a constant current source, of which a series resistor is a rough, wasteful approximation. (You need to drop voltage anyway (typical cell operating around 3-4V), so it's not all that bad.)

Tim

3 Supplies

NaClO3 crystals

Quote:

Originally posted by Xenoid Chloric: OK this my final result. After spending the night in the freezer at 20 below zero Celcius, I got these crystals with peculiar cubic characteristics different than sodium chloride cubes. The cluster in my hand has a notably large cube face so I tried to capture the suns reflection with it for photo drama . (Chloric) This is a bit off topic, but sodium chlorate was a popular choice for crystal growing recipes in more enlightened times. It is very easy (like alum) to grow large perfectly formed crystals. Now, if only I could find my crystal growing book (damn kids!) there is a lovely photo showing this! Edit: Ah! Finally found it! It was in a kitchen cupboard with the crystal growing chemicals! Interestingly they mention that if the growing solution has 6g borax for every 100g chlorate, you can entirely suppress the growth of the cubic faces and the crystal will take on the tetrahedral shape! So perhaps the more cubic shaped your crystals are is an indication of purity. Regards, Xenoid

Thinking of trying out a design for a chlorate cell...
Alfa Aesar sells a 20 mesh titanium gauze(made from0.003in wire).
Thinking of one of those wrapped in a cylinder form around a graphite anode.

Is the wire used in this mesh(their cheapest Ti mesh) too thin at all? It should not dissolve at all, but I usually prefer something beefier.

It's probably too resistive.

I don't know that there's any advantage to titanium, it just sounds cooler.

On the other hand, something like that could be very awesome for, like, filtering molten aluminum metal.

Tim

Chlorate using divided cell?

I was cruising the information superhighway looking for information on Li perchlorate (as one does) when I came across this procedure in Google Books for making Na chlorate. The procedure seems to contradict just about everything I've learnt about chlorate making over the years. The book is entitled:

The Preparatory Manual of Black Powder and Pyrotechnics By Jared Ledgard

and it can be found here:

http://www.google.co.nz/books?id=370UwG8CuNwC&pg=PA113&a...

The procedure can be found on pages 105-106 (note you need to read all of column 1 over the two pages, then column 2 otherwise it makes even less sense.

The method is based on a divided cell concept and the author seems happy to use just about anything for an anode. The porous membrane (a plant pot) is first "charged" - made conductive using magnesium sulphate electrolyte. It is then used in a divided cell to make chlorate. I can see that the anode compartment would be kept at a low pH and chlorate would be formed by diffusion through the plant pot. But what's the point of this method, what about anode erosion, the author does not even discuss it.

Regards, Xenoid

Hello,

Reading the opening lines it says, Sodium Chlorate is widely used in pyrotechnics also used to make Ammonium Chlorate and Perchlorate which are used in powerful solid rocket propellents.... Does not sound too good.


The battery charger only works when plugged in...

The entry on Lead Dioxide has been snipped

Have not seen anything like it before.

Dann2

Another circular filable crap book from a conartist / pyro expert pretender
and chemist wannabee .

Put the authors collected works on CD and call it a coaster

[Edited on 10-11-2007 by Rosco Bodine]

Aside from the questionable methods I also suspected his research as he even states that most of the literature comes from various patents but never references to specific ones! Very unprofessional. Also, in his chemical guide, he introduces reaction equations and states only the desired product be wrote as the result! Further more he states that balancing equations and listing all products is not done in the professional world That seems hard to believe considering that even non active by products can affect how the desired product is separated, identified, and made ready for purification.


Oh yea, using aluminum anodes in salt water and creating aluminum hydroxide. This would work for about 45 seconds

Check out the Ammonium Chlorate on page 463.....

... well, my battery charger only works when plugged in also!

Yes, now that I have perused some of the other "content" I can see there are quite a few "howlers"! Some good information, mixed with a lot of bad. Who knows whats what!

Perhaps it's fortunate that the lead dioxide section is missing

Regards, Xenoid

How to use PC PSU in a chlorate cell

Recently I'm starting the eletro-chlorate synthesis and still trying a very small batch with a 1A AC/DC adaptor. Seems very bad to massive production of chlorate..

But yesterday I acquired a old used ATX PC PSU and above it comes a small chart with the (resumed,quick & dirty) following info:

http://i242.photobucket.com/albums/ff176/tnitrato/ps-psu.jpg

Just to see the 'power' developed by this new power source, I plugged it in the wall (110V ac) and adapted the 12v yellow wire with the anode wire of my mini cell and the black with the cathode wire ..when turned on ,instanstaneosly, a fast and violent development of gas on both electrodes was reported and the thin wire on cathode released smoke..then I quickly turned off the PC PSU..all this happened in less than 5 seconds !!!

So, I'm full of doubts

how I may know the real current of the out-put using the above chart?
And how thick should be the wire used in the connections of the electrodes?

(sorry, I'm still a begginer in electrolysis , and also my knowledge on eletronic/related stuffs is very limited..also the search engine this time wasn't very helpful for me in this specific, although I know there are some threads on ATX PSU ..)

Chlorates are very pleasant to have lying around, not only because of their usefulness in amateur pyrotechnics (although very dangerous when compared to ClO4- salts) and also in other chemicals..
Thank you guys very much!

Quote:

Originally posted by Aqua_Fortis_100% Just to see the 'power' developed by this new power source, I plugged it in the wall (110V ac) and adapted the 12v yellow wire with the anode wire of my mini cell and the black with the cathode wire ..when turned on ,instanstaneosly, a fast and violent development of gas on both electrodes was reported and the thin wire on cathode released smoke..then I quickly turned off the PC PSU..all this happened in less than 5 seconds !!! So, I'm full of doubts how I may know the real current of the out-put using the above chart? And how thick should be the wire used in the connections of the electrodes?

So these 'load resistors' seems to be the same thing you are talking to use in ohms law.. And I will use after I get sure in what I'm doing...But for now, I still doing the procedure using the 1 amp power source @ 4.5V ..

The only improvement made today was to cut the plastic sides from this AC/DC adaptor and putting a cooler (which I get along with the ATX PSU in a eletronic store as 'souvenir') in one side and plugging this to another AC/DC adaptor (9.3V @ 850mA)..this all to cool the first adaptor (since using it in electrolysis make it getting very hot in some hours..) .. This is appearing to work fine to solve the heat problem..

It could be great if I could associate these two sources and running the resulting current in the cell (and after putting more graphite anodes ), but ... I dont know ! (Looking the battery example were associating in parallel could give more current and same voltage I didn't know what will happen if I will try the same with my power sources, because of the different voltages (one at 4.5 @ 1 A and the other at 9.3 V @ 850mA, as said before)

[Edited on 8-12-2007 by Aqua_Fortis_100%]

I wouldn't put anymore than about 4 Amps through that cell. Instead of spiral wire use a sheet of steel or preferably stainless steel for your cathode.

Not necessarily a multimeter, an ammeter say from a car or old instrument. If you have several small cells, just insert the multimeter in each one, say once or twice a day to check the current! If you find the current has dropped you will know something is wrong.... check the anode connections for corrosion.... Make a note of the current in a logbook to spot any trends!

Most computer supplies automatically shut down when over loaded. Only "modern" ones have +5V output greater than about 20 -25 Amps. The more modern supplies also have an output of +3.3 Volts at upto 10 -15 Amps.

The use of a resistor in the circuit is to lower the current (Amps) through the cell, this will at the same time lower the voltage across the cell. The sum of the voltage across the cell and the voltage across the resistor will equal the supply voltage! The voltage from a computer supply is constant (they are constant or fixed voltage supplies). Ideally you want a constant current supply, but that's another story...

Hi
Constructing a new electrolizer, well actually just wanted to brag, check it out
5.5 liter, 8 anodes and 8 cathotes, all graphite


[Edited on 11-12-2007 by hashashan]

Hashashan - I see you are still using "old fashioned" graphite (gouging rods), haven't you switched over to the "new - fangled" Co oxide (spinel) anodes yet.....

What is it built from - looks like plumbing fittings, I've thought about that, but I usually use bottling and pickle jars. At least you can see whats going on inside. How much current are you going to put through it!
That looks like a good EFFICIENT design, unlike a 10 litre, 12 rod cell I put together a few weeks back. My cell really needs some stirring. I really put it together, just to produce some bulk chlorate, as I am starting to run out. It can bubble away in the background. I wrote up the following item, but never got around to posting it:

--------------------------------------

........ Well, contrary to my comments about "filthy gouging rods" and wanting to try out MMO pool chlorinator electrodes, I have decided to first have a go at a relatively large sized chlorate cell. This is because I still have a couple of boxes of cheap gouging rods left and I also have several containers of chloride/chlorate "liquor" left over from recrystallising etc. that needs to be recycled.

My previous largest cell was about 4 litres, so I have decided to have a go at a "Tim (12AX7)-sized" 10 litre cell, based on an old plastic paint tub. This should be capable of processing at least 3.5Kg of NaCl as well as the old solutions.

The cell is sealed and the lid has 12 (9.5mm) gouging rods mounted through it. The rods are held in place using waterproof cable glands and "o" rings. One advantage of this design is that the used gouging rods can easily be removed and replaced, by unscrewing the gland. The "o" ring seals in gasses and fumes and prevents corrosion of the electrode electrical connections

The stainless steel (SS) cathode is constructed from an old cooking pot which I had bought some time ago for processing chlorate solutions, etc. But being made in India it only lasted for about a week before holes appeared and it started leaking. The handles were drilled off, and the base was cut off using a jig-saw with a metal cutting blade fitted. It conveniently fits nicely inside the paint pail witha bout a 10mm gap around it.

The vent tube is 6mm ID PVC tubing fitted similarly to the gouging rods, but using the next size down cable gland.

Image 1: Main components, SS cathode, plastic pail, lid with gouging rod anode assembly.
Image 2: Details of anode electrode connections and mountings.
Image 3: Close up, showing cable gland, gouging rod and "o" ring.
Image 4: SS cathode, in position and wired up.

[Edited on 11-12-2007 by Xenoid]

I like your cable gland idea, Ill need to find some of those. I just use hotmelt glue
and no need for the electric connection, I just soldered my wires to the copper.
Didnt want to use SS because of possibility of chrome ions running loose, and I do want to use that chlorate later in a perchlorate cell with the PbO2 anode.
The tube really is a simple 6 inch PVC pipe
And I still dont know how to make a good lid to it, this one is just going to sit over it, not really a lid .... more like a cover.

about stirring, I was planning to however my magnetic stirrer went in flames while making my PbO2 anode I had a little fire so still need to fix it, or maybe to make a new one

@ Tim and Xenoid, thank you guys.. I'm away from my house this week, so when I return I will visit the eletronics supply store and report my own adventures

Xenoid , this cell you've did really seems to be a very good cell to massive prodution of chlorates..with very high currents.. sure, this is the good and mad science in pure form

@hashashan, also thanks to present us with the good job you've did.. what is your spected yield of chlorate ? Did you notice fast rates of corrosion on graphites used as cathodes?

A little doubt ocurred now , all peoples says that is much better using linseed oil treated gouging rods , but I never had heard about the quantitative comparation on using treated gouging rods and no treated ones.. So How fast is the erosion of these two types operating at same conditions (temperature, current density, chloride conc. , etc)?

In the first cell I did (described above) , I tried to treat the pieces of gouging rods with a weird kind of brownish 'linseed oil' ("óleo de linhaça") .. I tried to mix this with acetone (60% the only OTC here) , but these compounds didn't have mixed ! It separated in two layers.. But anyway I put this in a glass pickle jar with the gouging rods and let some time(without vacuum).. after I have removed the gouging rods ., I let the rods 'curing' at about 4 weeks, but when I've used it in electrolysis, in short space of time (less than a minute) they had set free a weird mini immiscible bubbles which stay at the surface of the brine.. back to drawing board

@ Aqua_Fortis_100%

As I stated elsewhere, there is plenty of scope for amateur experimentation in treating gouging rods, I use a siloxane concrete treatment with about 10% linseed oil, it works OK but it's not perfect, it penetrates very well! I played around with candle wax dissolved in PURE acetone and in hexane camping fuel, and some others, I don't remember!

Sodium silicate? - Go for it, it's used as a concrete sealant after all, like the siloxane, and could work well in this application. Experiment, that's what this forum is about, after all...

Copper contamination? - I've never observed it, sure there is some green corrosion, but movement is always OUT of the cell, not into it!

Quote:

Originally posted by Xenoid Hashashan - I see you are still using "old fashioned" graphite (gouging rods), haven't you switched over to the "new - fangled" Co oxide (spinel) anodes yet..... The cell is sealed and the lid has 12 (9.5mm) gouging rods mounted through it. The rods are held in place using waterproof cable glands and "o" rings. One advantage of this design is that the used gouging rods can easily be removed and replaced, by unscrewing the gland. The "o" ring seals in gasses and fumes and prevents corrosion of the electrode electrical connections The vent tube is 6mm ID PVC tubing fitted similarly to the gouging rods, but using the next size down cable gland. Image 1: Main components, SS cathode, plastic pail, lid with gouging rod anode assembly. Image 2: Details of anode electrode connections and mountings. Image 3: Close up, showing cable gland, gouging rod and "o" ring. Image 4: SS cathode, in position and wired up. [Edited on 11-12-2007 by Xenoid]

Chloric - sorry to take so long in replying, I kept forgetting about your post, with all the anode excitement...

I bought the cable glands from a specialist electronics company called Jaycar, here in NZ and Australia. They have an IP68 rating which is the highest possible for dust and water sealing. They have a built in rubber and plastic sealing mechanism, however I bought the next size smaller than would normally be used, because it was cheaper and also they took up less room (this was when I was trying to fit 10 of them on top of a pickle jar). Size was not so important in my latest "bucket" cell. You can use the correct size glands "as is". If you use the smaller, cheaper ones, you have to cut off the sealing part and drill them out to 9.5 mm. Just get a small "O" ring that fits tightly around the rod, and put a bit of silicone grease on the assembly!

The clips are made from stainless steel. I picked up a whole lot of scrap at a recycling centre. I cut strips 6 cm long and about 1, 1.5 or 2 cm wide, (I made a range of sizes). The rods are 9.5 mm or 3/8" so you have to preform the clips around drill bits which are a bit smaller than the rods.

Here's where it becomes a bit hazy, as I made a large batch several months ago and haven't made any since!

I used an 8 or 8.5 mm drill and bent the strips into a "U" shape around it, then squeeze the ends in a vice as tightly up to the drill as possible. You'll end up with something roughly the right shape. Next force this around a drill (9.0 mm) and do the same thing, you may have to do a bit of hammering at this stage. You should get nice tight bends where the tag starts to go around the rod. Don't try to form them around something the same size as the rods, otherwise they will never be tight or look nice. I'm sorry I can't be more specific, it's a bit of trial and error. I got quite good at it and even threw away my first few attempts, because they were not "up to standard" Drill 3.5 mm holes ( say 1/8") in the tags, after you make them. All I used were two drill bits, the vice, a hammer and some metal snips.

[Edited on 14-12-2007 by Xenoid]

Reply

I know your seriously multitasking, so I was not expecting a rapid reply anyway. You explained enough to me, I understand that the drill form must be smaller than the rod I will use, its like drilling holes smaller than your tap bit before you tap otherwise the bit won't remove material and make your wonderfull threads.

Copper may be easier to fab, I might want to nickel plate copper strips. If solution does not "wick" up your anode then copper connection would be fine IMHO. Especially if your doiong O-ring seals and want not. Just don't repeat the 1986 Challenger errors and use the wrong size O-rings.

Chlorinator Electrode Chlorate Cell

I've finally got around to putting together a chlorate cell based on the chlorinator cell electrodes I rescued from a skip (see "Cobalt Oxide Anodes" thread, pp 2,4,6,7).

http://www.sciencemadness.org/talk/viewthread.php?tid=9572&a...

The cell is based around a tall fruit bottling jar I got from a recycling place for 50 cents. The cell is only about 1.1 litres but it fits the chlorinator anodes very well. The cell uses the two outer electrodes of the original chlorinator because thes were the least worn. It has a central SS cathode, with the 2 multi metal oxide (RuO2/TiO2) coated Ti mesh anodes on either side. Electrode spacing is 10mm. The cell was filled with saturated NaCl, about 350g.

The cell is running of a 5 volt computer supply, and at the moment is operating at 2.75 volts and 4.19 amps. A pair of 0.8 ohm 20 watt resistors in parallel are used to control the current. The ~4 amp current is quite conservative as I want to see how they behave, I may increase it later. The cell voltage is an amazing 2.75 volts, I've never had a cell running at a voltage of less than about 3.2 volts before! I guess it's due to the large surface area flat sheet electrodes, the close spacing, and the efficient MMO coating.

Needless to say the cell electrolyte is clear (Yay!!!) although a little orangey-brown scum formed initially, it has mostly faded!

@ Dann2

Yes, a tidy cell but as it turns out, a flawed design. BTW you should see the rest of the garage - an utter pig sty! What do you think about the low operating voltage (2.75 volts), I was quite surprised!

The orangey - brown scum actually got worse, much worse! When I came down to check it this morning (after 16 hours operation) it was full of brown and orange particles and so cloudy I couldn't see the electrodes. Fearing that the anodes had disintegrated, I switched the mutimeters on, and was relieved to see the electrical parameters were essentially unchanged.

I dismantled the cell, and immediately saw the problem. I had used two SS screws to attach the 2 Ti anodes to the PVC lid and also act as electrical terminals. I have always used this procedure in the past for SS cathodes, so used it for the anodes without thinking! I should have known better, SS is useless in anodic saline conditions.

The screw heads had about 5 - 10% corroded away...
In doing so they had contaminated the cell with Cr and copious amounts of reddish-brown colloidal iron hydroxide - just what I was trying to avoid, as this is a major problem with gouging rods!

After careful cleaning I have now coated the screw heads with hot glue. Epoxy would have been better, but I think the hot glue should hold up. I've filtered the solution, lucky I have a pressure filter....

http://www.sciencemadness.org/talk/viewthread.php?tid=9630

and put the cell back together, albeit with an orangey coloured electrolyte!

My Chlorate Cell

Your cell looks pretty good there, Xenoid.

Attached is a picture of mine.

The container is a 4L PET jar from Wal-Mart. The lid is PP. (I would have preferred PVC but it's kind of hard to find).

The studs that connect the electrode assembly to the lid are titanium, with titanium washers and viton o-rings.

The electrode assembly is a solid plate type, rated at 20 amps.

@ jpsmith123
We've been waiting a long time!

When are you going to fire up that baby... .. it looks really good! It will be sooo.. nice to have a clear solution to work with.

Did you have much trouble adapting the original chlorinator cell lid to your jar. As you would have seen in the other thread my chlorinator had an epoxy sealed top and no terminals. I think they are starting to make them all like that now!

That's a long exhaust pipe, are you planning on feeding it over to the neighbours place...

With that large capacity, it would probably benefit from a bit of magnetic stirring.

Be sure to let us know how you get on. I'm impressed with these electrodes so far, but its only early days. These chlorinators are supposed to last 5 -6 years in pool use, I wonder how long in a chlorate cell...!!!!

Goddammit!!!...

I just can't get this chlorinator electrode chlorate cell right.

This morning I noticed more orange-brown gunk floating around in the cell. Thinking the hot glue had lifted off the anode screws, I was already to replace it with epoxy. But, no, this time its the SS cathode that's starting to corrode badly along the edges. I haven't really had this problem before, just some minor cathode corrosion. Must be the relatively small cathode to anode surface area ratio, usually I have big cathode surfaces compared to gouging rods.

Moral of story, if you want a nice clean running cell use TITANIUM cathodes.

Funny, with all the graphite shit I had, I didn't give a rat's ass about the rusting "stainless" steel cathode I've been using. Methinks you should point your nose down away from the clouds!

Tim

Quote:

Originally posted by 12AX7 Methinks you should point your nose down away from the clouds! Tim

Developments in my cell

What do you mean, you "connected the .22 ohm resistor BETWEEN the +5V lines" The resistor goes in series with your cell to drop the voltage and limit the current. Wattage for that resistor at 4 amps should be W=I^2xR, W= 16 x .22, W= 3.52, 5W should be adequate. At 4 amps that resistor will drop the voltage by E=IR, E=4 x .22, E= .88 volts.

If you connect that .22 resistor BETWEEN +5v and 0V (earth) you will get I=E/R, I=5/.22, I=22.7 amps - that's probably at the PSU limit! That would be 113.4 watts that poor old 5W resistor would be trying to dissipate!

Mind you, even in series it will get warm, or even hot when running at 3.52W

That circuit should be OK, I've used something similar for constant current charging of NiCad cells in battery packs for caving lights. It's effectively using the power transistor as a variable resistor.

Yes, for you, the best thing is to solder directly to the remaining copper! You'll need a fairly heavy duty soldering iron. A lightweight electronic iron doesn't develop enough heat, well mine doesn't anyway. Put silicone grease on your connections, make sure no electrolyte gets on them...

[Edited on 3-1-2008 by Xenoid]

After various experiments and disasters over the last few weeks, I now realise that the SS cathode corrosion occurs almost wholly in the headspace area of a cell, and is particularly pronounced at metal junctions (needless to say). Any SS within the electrolyte and even metal juctions within the electrolyte are little corroded.

Colloidal Fe hydroxide and Cr contamination from the headspace area can be avoided. I have found glue lined heatshrink tubing or even a silicone grease coating, overlain with ordinary heatshrink will protect the SS in the headspace area. Screw connections to the outside world can be covered in hot glue.

The 10L, 12 rod cell I described in an earlier post, now has 5mm threaded rod cathode connections. These are covered in heatshrink and rise directly up through small waterproof cable glands on the lid. The entire electrode assembly is now mounted directly to the lid, and is completely gas and odour free.

So if protected correctly SS makes perfectly good, contamination free, cathodes. Ti cathode(s) for a large cell would work out to be quite expensive and I now realise it is not justified. Perhaps Tim is right, and I should get my head down out of the clouds, it's just that making these cells is such damn fun!...