387 replies to this topic

[hashashan]

with excess HCl

[gilbert pinkston]

prolonged boiling will work but how long i always use an indicator to be sure i dont want to take any chances

[gilbert pinkston]

i mean boiling with HCl of course but ALL chlorine oxide gasses must be driven off before neutralization

[sasman]

eh

Edited by sasman, 10 July 2007 - 12:03 PM.

[c-lab]

I have been trying to get some KClO4 for some time, but all the chemical suppliers I have tried only seem to offer AR grade, which is a little beyond my means at ?50+ per kilo!
So I have decided that the only practical option is to manufacture it myself. Has anyone here manufactured it, using either the thermal decomposition of KClO3 to KCl and KClO4, or the electrolysis of NaClO3 to form NaClO4?

You can buy pottasium perchlorate from hobbychem. Buy it in 100g and it not bad price making it is not worth the dangers and also vry expensive

Edited by c-lab, 22 May 2007 - 04:52 PM.

[Anders Greenman]

Sorry for dragging up this old topic, but I found it better than making a new one.
After failing with Car Battery Lead Dioxide anodes, I decided to make my own using graphite and plating solution (GSLD).
I've just recieved the key ingredients, but are lacking a good power supply. So far I've used an old PSU capable of delivering up to 15A at 3,3V, ideal for small scale chlorate cells indeed, but this time, I am aiming a little higher. I've considered buying a new one delivering 28A at 3,3V. If I add these together I can have around 30-35A without pushing them too hard. For some, thats ok. For me, I want more!

Both of them will then have a 5V channel unused capable of delivering almost as high current as the other one.
Because of that, I was wondering if it might be possible to run two different voltages in one cell?
Not on the same electrode, of course, but seperated by the electrolyte. Now, if this don't work, I will use my big MOT transformer based supply (100+A?)
but I don't think the energy efficiency is very good. Not a big issue in Norway though with prices around 15 US cents KW/h

[hashashan]

You actually managed to make a working GSLD? mine were always crumbly. i had my anode made on just rubbed on PbO2 on cloth and then cooated

[marble]

I have come across a local source of highly pure and cheap KCl so a chlorate / perchlorate cell seems like a good idea seeing as there is no local (even domestic) supplier for kclo3 and kclo3. Basically if you want in Australia you have to import it or make it.

Seems fairly straight forward seeing as i have half the stuff laying around anyway (got a big transformer thats rated at 4v 50A) so the power supply shouldn't be a problem. That leaves the anode, i may be able to get my hands on half a kilo of lead dioxide but finding a piece of graphite and coating it is a bit of a turn off. That really only leaves platinum coated nickel wire, which i have no idea where to buy and im told it will only work for a small amount of time.

You thoughts?


/Probably been answered in the past 18 pages but i don't have a few hours when im still on the drawing board to speak

Cheers

[marble]

Decided its best to make a GSLD anode, only problem is getting nitric acid. If i cant get that i can get lead and copper nitrate off a certain ebay seller but is it possible to use hydrochloric acid instead?

http://www.wfvisser....EN/gsld_EN.html

Mentions lowering the solutions pH to 1 and then later immersing the anode in 10% HNO3. The only problem i see with hydrochloric acid is that it wont attack the copper.

[marble]

More progress, ive managed to find a seller who will sell 10cm platinum coated anodes (2.5 micron) for $30US a piece. Its still cheaper to find some nitric acid and make a lead dioxide anode but so far thats proving to be quite a problem. For a cathode ive got some 3mm Ti sheet here, its 6Al6V2S.

Edited by marble, 13 July 2007 - 03:07 PM.

[Anders Greenman]

You actually managed to make a working GSLD? mine were always crumbly. i had my anode made on just rubbed on PbO2 on cloth and then cooated

Nope. I haven't even prepared the nitrates yet (holiday). Rubbing on cloth might be a good idea, but i prefer GSLD. Seems to be a little more effective if you get the coating right.

marble: Graphite should be problem. Gouging rods can be bought from your local ESAB supplier or something similar.

http://products.esab...41.asp?id=92967

Nitric acid is another story though. I got mine from a rare pigment store.

Edited by Anders Greenman, 15 July 2007 - 09:02 PM.

[hashashan]

how are GSLD better??? one crack and you can throw your anode away. If you insist on coating with a conducting substrate use titanium because if your anode cracks it wont be eaten away but just coat itself with an oxide layer(hopefully).

I prefer massive GSLD it is much better then a coating. But it does require a far more complicated setup. Anyway I would never recommend to make GSLD, even if you'll manage to make a nice one it wont last.

[marble]

Sure they are not great but considering i can make them for next to nothing (i have a box of graphite rods, 50kg of lead sheet and 5kg of copper sheet) it doesnt bother me if they only last for a few weeks. Ti substrate sounds interesting but there is very little material on its manufacture, plus the fact that Ti sheet is hard to come by

[Anders Greenman]

how are GSLD better??? one crack and you can throw your anode away. If you insist on coating with a conducting substrate use titanium because if your anode cracks it wont be eaten away but just coat itself with an oxide layer(hopefully).

I prefer massive GSLD it is much better then a coating. But it does require a far more complicated setup. Anyway I would never recommend to make GSLD, even if you'll manage to make a nice one it wont last.

I think cloth coating seems messy and may flake off more easily. Never tried it though. Will consider your method, but what type of cloth do you use?
Cotton? Polyester? Wool?

[hashashan]

about GSLD : you are saying you can make them for next to nothing..... can you? yeah, of course you have the reagents but can you make them eithout holes?(this is very difficult) most of the GSLD's will crumble in your hands even before you put them in your cell, one tiny crack is enough to kill your anode in a very shiort period(no, not weeks, im talking about hours). You are welcome to try and report your results, if you will be able to do it ill be glad to hear about it.


About the cloth. It wont crumble, you are making a VERY thick anode. mine fell from about 1.5 meters several times and didnt flake off. I dont think the type of cloth matters, i just used a sock