Iodine 7% Leach for Gold

Has anyone here tried using Strong Iodine Tincture 7% for leaching of gold?? I'm investigating this technique and it appears to be sound but slow and more expensive..

No, I never tried this technique. Please share what you've found.

I've heard of it. Chlorine will do the same job and it's more readily available. Please share what you have found.

I have read about it but never tried to use it yet, but the info looks great. I read it is highly selective for gold, But slow.
And I read somewhere it could be used with dbg as well.
I think it is much more expensive than other methods in upfront costs but it is re-useable so in the long run may be equal to or cheaper than other methods.
I saw it in the feed store last time I was there, some kind of hoof treatment, about 8.99 a pint.

Here's my first iodine strip. I put in about 2 ounces of material. Hopefully the picture posts o.k. and you can see what the material looked before and after. Most of this was from memory sticks. So small pieces but then again I'm practicing.

I let this go overnight versus waiting a day or two but I just wanted to see if it was working or not. So there remains a couple small specks of gold still left on the fingers but most appears to be stripped clean. Hurray!!!

I made two batches of this and the other I put in various CPU's like Pentium and AMD. What I noticed is some of these parts seems to be stripping great but others appear to be stripping much slower. I wonder why? Any ideas?

I am playing with this technique and if anyone is using this PLEASE let me know. I could use some help..

Gold-Digger,

Are you getting gold flakes in your solution or have you tested the liquid to see if it has Au dissolved in it?


I'm wondering if the purple color you see is residual iodine or colloidal gold (most probably the iodine). If you want you could take some rubbing alcohol and rinse the fingers that you have 'stripped' to see if the gold shows back thru the purple. You may not have removed anything, you may have just discolored the gold foil. Can you confirm the gold has been removed into solution? If it has you may be onto something if you can get past the messy nature of iodine. Another problem will be the testing of the solution as iodine gives a purple color in solution. Keep us posted.

Nice work.

Steve

Gold-Digger,

Here's a link that will get you started on getting your gold back from solution if you have succeeded in stripping the gold:

http://patft.uspto.gov/netacgi/nph-...50&s1=4319923.PN.&OS=PN/4319923&RS=PN/4319923

Looks like you can recycle your iodine solution too!

Steve

I put in a couple CPU's in a different Iodine solution and a lot of the pins dropped out and are now resting on the bottom of the container. Plus they are almost black colored. I also wiped down a few areas of these memory stick end fingers with alcohol and no colored returned.

What has me baffled is some of the pins still look nice and gold colored almost like nothing has happened. While others on the same CPU other pins are completely wiped clean of any gold. Very weird but guessing that maybe these pins have a lot more gold on them or somehow an oxide got built up around a few of them during the etch process... but weird!

I know I'm suppose to use a stirring method to keep the solution moving around and perhaps it creates small pools of leaching solution while other areas end up void within the bath.. I have a small aquarium air pump which I was told would keep the solution moving. Maybe that's the key to this funny etch pattern? But in an acid solution?????????

Gold-Digger,

The air bubbles may be protecting some areas of the gold with air. The air is possibly displacing the etchant and therefore creates odd etch patterns. You should try agitation with some sort of vibrating motor or something similar.

Did you check out the article link I posted?

Steve

Gold-Digger

Iodine leach goes to work immediately on Gold, then Platinums, then Silver, in that
order. It tends to ignore the other "Trash" metals. Naturally, it is about PH 4-5,
and is kept there, especially in the presence of Alkali metals, by adding small amounts of HCL acid.
Typically 24-48 hours to collect fine gold.
The leach will only stop working when the PH rises to 7.
Mix everything together in your container, making sure you have fresh air circulation, as confined
Iodine fumes can be toxic, and burn your eyes. For agitation, you can add a small air bubbler with
stone at the bottom of the leach tank, like
those used in aquariums, to keep the mixture circulating.

Will potassium iodide in water work the same or do you need some free iodine in the mix? Got info on ratios, percentages, weights, volumes, etc.?

Will potassium iodide in water work the same or do you need some free iodine in the mix?

Click to expand...

I used "Lugol’s Iodine". This is simply Iodine dissolved in a solution of Sodium Iodide.

Got info on ratios, percentages, weights, volumes, etc.?

Click to expand...

Ill have to dig up my notes on it.


Gold-Digger

To get your gold out of your Iodine solution add some NaOH and the
solution will go colorless.
Your gold will now slowly settle to the bottom as a black powder.

Here are some ratios I came up with from a University Document :

4g:2g:10ml - KI:I2:H2O Hot (70C) 280 nm/min


Steve

O.K. this answers a lot of questions. THANKS!!!

Sorry but more questions...

1. Are you using any type of precipitant such as Zinc or anything like that when you use lye to a Ph of 6 or 7? I have a compound I purchased specifically for this process but probably not the right place to list this. I can email you the info if you want it..
2. Are you watching the ORP? And a dumb question but what chemical are you using to control the ORP (it is a factor of the HCl to H2O or Iodine to Water, etc?).. I was told to check this and ensure it never goes above 900 otherwise it will start leaching iron but not sure how to control ORP readings.

After it settles then you filter and dry are you:

1. Firing with a Flux as described by C.W. Ammen (Recovery and Refining of Precious Metals, 2nd edition) at around 2000 degrees F (1100 C)? The flux he describes is sodium carbonate, lead monoxide, silica (sand), Borax, wheat flour, etc.....
2. Are you buying a pre-made flux from someone such as Action Mining?
3. Are you just using Borax and ash?

I currently have a pre-made flux plus I have a box of Borax. From what I understand the pre-made has lead in the compound which creates a lead button when firing?

Or what are you doing in the firing of this? I have 2 different furnaces that will go over 2000 F and crucibles. One is specifically for melting metals like gold and silver using a graphite flask.

I'll use my respirator to check the iodine solution I have going right now and will connect the aquarium air bubbler to my next batch (thanks!).

Just starting to experiment with this technique.
I put a small bathch of gold plate pins in a test tube with Lugol's iodine. The gold stripped off in about an hour or two at room temp. No fumes.

The liquid turned a clear yellow color with a white granular precipitate. The yellow liquid had some gold fizz around the rim typical of dissolved gold.

Then I used Lugol's to take the gold off of the small pins from a number of K6 CPU's. Not much else to get. I noticed that as the lLugol's turned clear, the stripping stopped until I added more Lugol's. I assumed that the iodine had been bound up in the gold and cleared the solution, but I don't know that for certain. I haven't tried just adding HCL to the spent Lugol's, but if there's no iodine left to act on the gold, what's the object?

The original patent precipitated the gold with high alkalinity, so keeping it acidic will keep the gold in solution, but I don't know if it will enhance the stripping or not.

The white precipitate can be filtered off best with a LOW vacuum filter flask (otherwise it sucks a hole through the filter paper). I don't know what the white stuff is, but there's not much of it.

I have tried the tin solder in HCL for testing presence of gold, but not experienced enough. Going to make soem standardized gold solutions with known gold concentrations for testing purposes. I don't trust my stannous chloride mix...yet.

Comments?

MacDaddy,

The stannous chloride won't show proper results due to the iodine. The iodine solution will blacken when the stannous chloride is added and this prevents you from determining if gold is present or not.

I tried some iodine solutions when this topic was originally posted and didn't have good results. My gold was still on the original parts, merely discolored by the iodine. I found this out when I rinsed the original parts with muratic, the gold showed back up when the iodine layer was removed. The iodine only removed a very small amount of the gold. My tested solutions also changed from clear to pale yellow and back again a few times. I managed to percipitate some copper iodide (? looked like black rat pellets) out of a small amount of the iodine solution with lye. Since the gold was still on the parts I haven't done anything with the remaining iodine solutions.

Steve

While working for a man that later became my partner, Richard Homick wrote an iodine patent that supposedly was the best. I never tried it but, I heard about it almost every day. The patent number is 3957505

http://www.google.com/patents?id=oLZ7AAAAEBAJ&printsec=abstract&zoom=4&dq=3957505#PPA3,M1

To find out the basic formula, go to page 4 and read the "Example" section at the bottom of the page.

Iodine and potassium iodide are expensive but, the beauty of this formula is that the chemicals can be recycled with hydrogen peroxide and used over and over again. People have asked for something that could strip gold plating selectively. This could be it. I haven't tried it because, at the time, I was perfectly satisfied with cyanide stripping. I would behoove everyone to check out this patent.

I have used Iodine with good results. It can be very selective and is somewhat slow. Yes as you will see, you can recover the Iodine and re-use it. Here is the procedure I use.

IODINE LEACH PROCEDURES

1. Mix in clear container:
1 part scrap ( may contain Gold, or any of the PGMs)
1 part 7% or 10% iodine
10 parts water
Agitate (I use a bubbler like used in a aquarium)
Let set (Leach) 24 – 48 hrs-should get darker (the darker the better)
Filter to clear (3 coffee Filters)
filtered leach will be clear but colored
Retain clear leach

2. Drop Iodine:

Add ½ t of Sodium Nitrate
Wait to drop
Filter

Alternate procedure:
Add Clorox slowly (Iodine will coagulate & drop as blue layer/black precipation)
Filter (to remove Iodine)

(Keep the Iodine in a covered container, as it will vaporize in air.)

3. Drop PGMs:

Mix equal parts Clorox and household Ammonia in small amount, use fresh.

Add small amount to Iodine free leach to precipitate yellow powder (Platinum)
Filter & dry (3 coffee filters)

Wait 1 hr
Palladium should fall out as dark precipitant
Filter & dry (3 coffee filters)

4. Gold:
Gently raise leach pH to near but not over 7 with Sodium Hydroxide (lye solution), pH will continue to rise as gold falls out. White precipitants are Mono-atomic.(you got the pH above 7)
Wait to complete drop, gold should fall out
Filter with 3 coffee filters to clear


CAUTION:
Mono-atomics: Become radioactive when heated. It's best to just discard them, it is very unlikely that any of us amiatures can coax it back to a non mono-atomic state


I obtaine this procedure from Mike . Here is the link, but the information is no longer available free. Now you have to buy the report and all of this is not in there. I got it when He had it posted openly on the site, several years ago.


http://www.goldmineworld.net/

Her is another patent you might find interesting since is based on this procedure

Rainmaker

How do you feel about the David Hudson monoatomic thing? Have you ever tested the stuff for radioactivity?

I have read a fair amount about this and looked at the patent, it is not a simple process by any means. Most of what I have read is very interesting and even the "Lost Books Of the Bible "the Apropha" talk about this. I wouldn't go so far as to embrace some of the claims, but find it interesting enough to want to look into further.

Never produced any, a little scary.

So much to do, and so little time.

Rainmaker