Povidone Iodine and Gold Leaching.

[glenns]

Hi guys,

FYI, povidone iodine (the huge iodine bottles seen at any Wal*Mart or Target) can not! be used for gold leaching! Only elemental iodine and potassium iodides (Lugol's, etc.) can.

Why can't povidone iodine be used? Because povidone iodine is an iodine complex with the excipient and film-former povidone, that's why. And as a complex, povidone iodine is molecularly distinctly different than elemental iodine and iodine's salts (potassium iodide, etc.)

Povidone is a film-forming celluloid powder that was initially used as a blood plasma replacement for WWII soldiers. It later found its way into foodstuffs to make them more creamy, into pharmaceuticals to coat our pills and make them slimy when swallowed, and relevantly, into an iodine/povidone complex. So when you're trying to leach out the gold usine povidone iodine, you're using a complex; half of which is made to make your ice cream melt slower and your shaving cream to glide on your skin smoother.
Povidone iodine was created as the safer alternative to iodine tincture.

So, if you want to leach gold the iodine way, you have to go to eBay. There are a ton of eBay Sellers who are selling iodine, both elemental iodine up to 250g as well as the sought after salt, potassium iodide--up to 500g. So cheap and in such high quantities of the aforementioned iodine makes reusing your little bottle of Lugol's solution a non-issue.

I

 

[RGJohn]

Hi guys,

FYI, povidone iodine (the huge iodine bottles seen at any Wal*Mart or Target) can not! be used for gold leaching! Only elemental iodine and potassium iodides (Lugol's, etc.) can.

Why can't povidone iodine be used? Because povidone iodine is an iodine complex with the excipient and film-former povidone, that's why. And as a complex, povidone iodine is molecularly distinctly different than elemental iodine and iodine's salts (potassium iodide, etc.)

Povidone is a film-forming celluloid powder that was initially used as a blood plasma replacement for WWII soldiers. It later found its way into foodstuffs to make them more creamy, into pharmaceuticals to coat our pills and make them slimy when swallowed, and relevantly, into an iodine/povidone complex. So when you're trying to leach out the gold usine povidone iodine, you're using a complex; half of which is made to make your ice cream melt slower and your shaving cream to glide on your skin smoother.
Povidone iodine was created as the safer alternative to iodine tincture.

So, if you want to leach gold the iodine way, you have to go to eBay. There are a ton of eBay Sellers who are selling iodine, both elemental iodine up to 250g as well as the sought after salt, potassium iodide--up to 500g. So cheap and in such high quantities of the aforementioned iodine makes reusing your little bottle of Lugol's solution a non-issue.

I

My bottle also states that it contains a mere 1% of actual iodine. That would hardly seem efficient.

 

[Pogo]

Hello!
I have been experimenting with gold leaching. I am using 10% veterinary povidone-iodine SOLUTION ( do not use the 'SCRUB' or '10% Betadine Scrub' - too much soap in it.). I recycle up to a gallon of this through a 5 gallon bucket over the course of a day. Based on three ( for a reasonable statistical average) before and after fire assays, I am realizing 91% extraction. In hard numbers, out of a 500-528mg dore button, before leaching I get a 14-16mg button after leaching. Iodine being only about 1% soluable in water is sustained in a 10% solution as the povidone behaves as a reservoir. As Iodine is depleted from the reservoir the solution becomes more clear. This yields a visual clue indicating a 'pregnant' solution.
So far I have attempted to precipitate by titrating with 'clorox'( 5.25% hypochlorite soln.) . My precipitate is mustard colored, heavy, and will not melt in my furnace. My furnace is using air blown propane in a 1 ft. square box. I use 'J' type thermocouple to determine temperature. I have determined temperatures as high as 2150 degrees Farenheit.

So at this time, I am stuck and puzzled as to why this precipitate will not melt, and what is it?