Jump to content


Photo
- - - - -

platinized titanium anodes


  • Please log in to reply
29 replies to this topic

#21 WSM

WSM

    Firebreather

  • Full Member
  • PipPipPipPipPip
  • 2,853 posts
  • Gender:Male

Posted 21 June 2019 - 10:36 PM

Cookson certainly sell small amounts of platinum you can buy inches or mm of Pt wire for a fair price based on UK bullion price and (iirc) UPS carriage.
https://www.ottofrei...ock/metal-stock is just google's first offering of a supplier selling platinum bar and rod stock in small quantities and small prices! no recommendation of this one supplier made or inferred, but nothing known against either.


I'll hold off for now. I can't afford such an extravagant expenditure at this time, but perhaps later...

For now, I'm content to work out the details of pure sodium chlorate production, which, if I can get a good supply of, I'll continue my perchlorate research.

WSM B)

Edited by WSM, 21 June 2019 - 10:42 PM.


#22 markx

markx

    Pyromaniac

  • Full Member
  • PipPipPip
  • 65 posts

Posted 27 June 2019 - 07:38 AM

I moved along the same path..........first trying to get a stable procedure to yield chlorate, after it had become a nobrainer I tryied my hand on perchlorate electrosynthesis. Both of them I can now yield on demand, but to be honest I have no reasonable use for the product. It piles up faster than can be consumed for practical purposes. But it feels good to be able to have such capability :) 

 

The neat thing I found about the platinized anodes during my experiments is that the popular belief about chloride contamination extinguishing their soul quickly, does not really seem to be a major issue. In fact I have used the diy platinized anodes to perform a full conversion starting from plain sodium chloride and going all the way up to perchlorate. Damage shall start to manifest itself at the end of the perchlorate conversion stages when anode potential rises due to chlorate depletion and starts to promote passivation. When starting from chlorate, the chloride contamination in stock solution is not a problem and trying to purify it makes really no sense at all. The electrochemical processes in the perchlorate cell shall yield an equilibrium chloride concentration anyways (even if one starts out with perfectly pure chlorate).

 

What seems to be a major issue is high anode potential (polarisation due to the electrochemical processes not being able to keep up with the power supply and hence yielding a charge difference on the electrodes). In my experience, if one keeps the current density around 100-150mA/cm and does not apply more than 5V across the cell, then usually the polarisation is not strong enough to cause problems with anode damage or passivation until the very end of conversion. But cranking up the cell voltage over an excess of 5V and letting current density on the anode rise sky high will quickly end in full passivation of the Ti substrate. So it is a waltz of balance....



#23 davidh

davidh

    Pyromaniac

  • HE Qualified
  • PipPipPip
  • 85 posts
  • Gender:Male

Posted 27 June 2019 - 09:35 AM

I wonder about buying several one gram platinum bars, and making a titanium structure to mount them in. Then you always have the option of selling the worn bars as scrap platinum. And it would be easy to calculate the surface area.

 

https://www.apmex.co...num-bars-rounds


Edited by davidh, 27 June 2019 - 09:35 AM.


#24 WSM

WSM

    Firebreather

  • Full Member
  • PipPipPipPipPip
  • 2,853 posts
  • Gender:Male

Posted 27 June 2019 - 12:37 PM

I wonder about buying several one gram platinum bars, and making a titanium structure to mount them in. Then you always have the option of selling the worn bars as scrap platinum. And it would be easy to calculate the surface area.
https://www.apmex.co...num-bars-rounds



If you have a spot welder (resistance welding), I see no reason you couldn't spot weld some one gram bullion pieces to CP titanium and use that as an anode for perchlorate production.

Other means (I'm thinking of mechanical fastening) of fixing Pt to a compatible substrate would likely also work.

Let us know which one you use and how it works.

WSM B)

#25 WSM

WSM

    Firebreather

  • Full Member
  • PipPipPipPipPip
  • 2,853 posts
  • Gender:Male

Posted 27 June 2019 - 12:42 PM

When I commented on the expense of platinum, I was unaware that the price has dropped to nearly $800 USD/Troy Ounce (31.1 grams).

If I can find a reasonable seller of pure platinum, I may try to get 3 grams to experiment with. I hope the cost is under $100 USD.

WSM B)

Edited by WSM, 27 June 2019 - 12:44 PM.


#26 Arthur

Arthur

    Firebreather

  • HE Qualified
  • PipPipPipPipPip
  • 3,068 posts

Posted 27 June 2019 - 03:37 PM

Jewelery materials stockists sell "enough for a ring" pieces of gold,platinum and iridium for almost easy prices. The secure bullion delivery charge may be more than the metal cost. The issue may be that bullion comes down to 1mm thickness whereas 0.25mm would be a better thin electrode with less material mass for a given area. The up side of sheet Pt is that you can use two sides so 1" x 1" becomes 2 square inches for electrolysis if pared with two suitable other electrodes.  



#27 markx

markx

    Pyromaniac

  • Full Member
  • PipPipPip
  • 65 posts

Posted 28 June 2019 - 01:07 AM

When I commented on the expense of platinum, I was unaware that the price has dropped to nearly $800 USD/Troy Ounce (31.1 grams).

If I can find a reasonable seller of pure platinum, I may try to get 3 grams to experiment with. I hope the cost is under $100 USD.

WSM B)

Three grams seems like several lifetimes worth of material if you plan to go the chloroplatinic acid route. Well justified if one plans to use solid sheet Pt instead of the plated Ti.

A fraction of a gram shall do the trick for acid, so your initial expenses should not be higher than about 30 bucks regarding Pt, depending of course on how good a deal you can get. 



#28 Arthur

Arthur

    Firebreather

  • HE Qualified
  • PipPipPipPipPip
  • 3,068 posts

Posted 28 June 2019 - 08:44 AM

No-one who sells Pt will ship it without using a reliable courier and there is a $30 invoice for a start.



#29 WSM

WSM

    Firebreather

  • Full Member
  • PipPipPipPipPip
  • 2,853 posts
  • Gender:Male

Posted 29 June 2019 - 10:29 AM

Three grams seems like several lifetimes worth of material if you plan to go the chloroplatinic acid route. Well justified if one plans to use solid sheet Pt instead of the plated Ti.
A fraction of a gram shall do the trick for acid, so your initial expenses should not be higher than about 30 bucks regarding Pt, depending of course on how good a deal you can get.



If I venture to do this, I'll buy the metal while the prices are down.

I've long considered forming a 1 gram bullion piece into thin sheet (foil), that I can carefully spot weld into a CP titanium frame, all for a perchlorate anode.

I like the idea of plating the platinum onto the titanium substrate in multiple layers, using the "paint and bake" method you described. If I use many more layers, I hope it will hold up for much longer than you described. We'll see...

WSM B)

#30 WSM

WSM

    Firebreather

  • Full Member
  • PipPipPipPipPip
  • 2,853 posts
  • Gender:Male

Posted 30 June 2019 - 09:23 PM

No-one who sells Pt will ship it without using a reliable courier and there is a $30 invoice for a start.



My hope was to find a bullion dealer in my area who's willing to sell some at a (hopefully reasonable) fixed markup above spot price. It appears that most Ebay sellers simply double the price they pay, and that's unacceptable to me.

I'll try to look into it soon, but it's not high on my list of priorities right now.

WSM B)




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users