# Iodine gold leaching



## badastro (Aug 15, 2007)

This link provides some info on iodine leaching http://www.prospectorsparadise.com/html/leaching.html

It is rather vague...

I think the process is to get some iodine salt, add a little bleach to partially precipitate some elemental iodine which turns the solution blue, and add gold bearing materials.

The gold ladden solution is red brown, and it is filtered clean. A solution of lye is added to precipitate the gold as black powder.

The iodine is recovered by adding a lot of bleach to precipitate the iodine to be recovered for later use. Elemental iodine is converted to gold etching solution again by adding lye solution.


Does anyone have experience with iodine leaching? It seems to be an interesting way to process low grade scrap effciently. I don't know how copper or other metals will affect the process though....


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## ChucknC (Aug 15, 2007)

I spoke to Prof. Williams about this. He told me that he wasn't satisfied with the results(only seems to work half the time at best). That article was posted before he had a chance to work out all the bugs. He died before he could update the article. Man I miss Ken.


http://webpages.charter.net/kwilliams00/bcftp/bcftp.htm 
This is the original site. Most of his information is pretty good. It got me started on the chemical aspect of prospecting several years ago.


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## blueduck (Aug 15, 2007)

the information The late professor details out makes sense on the tellurides and the need to burn off the sulfides if any are present which in turn when processing catalytic converters to recover PGM's the need is present to also deal with the sulfides present before acids will get to the metals to put into solution....

I live near [about an hour away] from where the chinese had ovens built for the purpose of gold recovery [many think it was for baking bread, which they did also but would not have had the need for so many ovens] then they used different acids and such to recover the gold out of the river sands....

His treatise on fire assay makes me want more and more to one day end up with the entire apparatus in my laboratory [I feel more and more like a mad scientist than an ordinary person with a shop or basement, though I aint gonna be doing most of this anywhere near the basement for safety sake]

Anyhow the information may be incomplete in some terms, but it gvives a place to start or mayhaps a place to fill in where a person has left off some, the good outweighs any negative and as always no mater how sound advice is, always double check the methods before proceeding with the unknown.

thanks for the links

William


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## EVO-AU (Sep 19, 2007)

Mr. Bad: 
I use 7 - 10 % Iodine from the local feed store. About six dollars for a pint. The following works for me leachng Au from clay. 

One oz Iodine, one quart of water ( distilled ), HCL to bring the Ph down to about 0.5 to 1.0,, mix well let set for 48 hours and then filter. Just hope you are Iodine tolerant. The Iodine is getting hard to get because the meth idiots use it for cleanup. If you want the rest of my process, let me know. EVO-AU


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## rainmaker (Sep 19, 2007)

There is already a lot of information on this forum on this subject. Do a search foe Iodine and go to the subject "Iodine 7% Leach for Gold" for more information, including some interesting patent information.

Rainmaker :wink:


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## Anonymous (Oct 19, 2007)

I haven't had the chance to put it into practice yet, but will when I have the chance. Ken Williams got me to thinking about it when I looked at his site. I felt the info was a lil sketchy, but was a place to start. I have been researching the subject and found some verrrry interesting info on several iodine processes. Here's a link to a patent site. Free to join, and costs NO money to view the material.
http://www.freepatentsonline.com/result.html?query_txt=iodine%20leach
I have a claim on the Fraser River below Lytton. In the '70's there was testing done far upstream, above Lilooett. Assay yielded approx. 2.5 oz gold and .3 oz platinum from just over 1 ton of gravel from the beach.
On my own claim, the one field test I did on the beach was approx. 1/3 oz visible gold per yd. of gravel. This is previously worked ground so I have no idea what lies elsewhere on the claim. Given the gold runs fine to very fine, and that blacksands will contain up to 10 times more gold that is below 70 microns (invisible), my field assay could well be 1oz/yd. Leaching seems to be the only alternative to liberating those values. I have tried acid leaches. The massive amounts of iron, nickle etc. eat the acid leach before it can even begin working. Magnetic separation is not an option as much fine gold gets caught up in the magnetics. PGM's can also be para-magnetic. Iodine leach makes most sense as it mostly ignores the trash metals, and is recyclable.However, according to the research done by the patent filers, iodide AND iodine must be present for it to work effectively. 2:1 ratio of iodide to iodine.
There are about a dozen or more papers done on this leaching going back to the early 1900's. Patents cite other patents in their bibliography, so look at those too. Tough slogging, but well worth it.
I will post my results with iodine extraction when I get the chance to try it. Might be awhile until I get the time. Sorry for the long post.
Cheers.... Stu


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## goldsilverpro (Oct 19, 2007)

Welcome to the forum. Good post, Stu. Iodine/iodine has always sparked interest on the forum, but no one has ever come up with anything solid. Please keep us informed. Good luck.


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## EVO-AU (Oct 20, 2007)

Goldpro: I have great success with Iodine leaching, at least with my ore, but the thing that gripes me is that it is so doggone slow. But the yields are nothing to quibble about. . It has been about a year now that I first started with T/6 and Iodine. No problems, just minor hurdles from time to time. EVO :roll: P.S. I wish I could find more pockets like this. Few and far between. That is why Au is so rare. Au is where you find it.
Check into Geochemical prospecting. An awful lot of work and loads of tests, but it is exciting to find the pathfinders. EVO


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## Anonymous (Oct 21, 2007)

Right on, Evo. Have you tried heating your leach? Heating any chemical reaction will increase the effects. From what I read in the patents, heat and agitation increased the results. Here is one of the patents I came across in my search. It uses iodine, sugar and grain alcohol. The results from different ratios is in the article.


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## EVO-AU (Oct 22, 2007)

Stu: Thanks for the info; Iodine works better when cool, even at room temperature it will gassify or evaporate unless covered. EVO[/b]


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## EVO-AU (Oct 22, 2007)

My post of Sept 20th, 07 is a bit off. I am sorry, I had my mind on something else. I go over my notes and posts from time to time and found this silly thing. Okay, I edited it out. T/6 cannot, as far as I know, cannot be used as a leach at the same time as Iodine. As a precipitant with Sodium Hydroxide, possibly. Anybody got anything on this ?
My deepest apologizies to you all. Sincerely, EVO
:arrow: :idea: :?:


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## Anonymous (Oct 24, 2007)

Hi EVO. Was just thinking about your leach being slow. Would it be faster if you used pure elemental iodine? I hear it is hard to get because of the anti-terror / anti-drug watchdogs. What if you had a home business.... a company. Say a...... "proprietorship" or somesuch. You might be on a list when buying, but yer not doing anything wrong with them, and access to chems would be easier.
That's what I did, and have no problems purchasing chems. When asked the purpose of the chems, I tell them for refining PM's. Makes sense to them, they are satisfied.
Sigma-Aldrich sells online for reasonable price on most things. I learned one thing tho..... if you buy from S-A or other big companies, the shipping address is NOT your home address. They will not ship to residential addresses. Have it shipped to your work instead ;o)....... or just lie yer ass off and hope you get away with it LOL.


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## rustbucketguy (Oct 12, 2011)

Did you ever get any good information on iodine leaching of gold such that you could do it on a regular basis? I am trying to get the process running so that I can look at several types of available clay, primarily looking for micron gold in known gold areas. Am using tincture of iodine, acidified with HCl (will also try nitric acid) which is then kicked up to iodate with dry hypochlorite. The orange solution in the beginning turned a dark red almost immediately but is not doing that any more as I get to the bottom of the bucket of my clay supply. When I add sodium metabisulfite, the orange solution goes colorless and then a black precipitate drops out. (Basement chemist described this same progression of color changes but used NaOH to drop the values. Tried that but got a lot of iron hydroxide).

Did the lead foil thing with the washed precipitates and then cupelled the lead button, got a very tiny gold BB. Still working with the leach but it is very possible that there is simply no gold in the clay I am working with.

Anybody out there satisfied with their procedures for iodine leaching?


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## Oyawre (Apr 23, 2020)

Trying to get the full process. Appreciate your help



EVO-AU said:


> Mr. Bad:
> I use 7 - 10 % Iodine from the local feed store. About six dollars for a pint. The following works for me leachng Au from clay.
> 
> One oz Iodine, one quart of water ( distilled ), HCL to bring the Ph down to about 0.5 to 1.0,, mix well let set for 48 hours and then filter. Just hope you are Iodine tolerant. The Iodine is getting hard to get because the meth idiots use it for cleanup. If you want the rest of my process, let me know. EVO-AU


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## galenrog (Apr 23, 2020)

EVO-AU has not logged on to the forum since 2012. If the question is directed at him, you may want to try a PM.


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## FrugalRefiner (Apr 23, 2020)

But we only get PMs if we log onto the forum.  

Dave


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## anachronism (Apr 23, 2020)

FrugalRefiner said:


> But we only get PMs if we log onto the forum.
> 
> Dave



I was going to say exactly that... haha


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## galenrog (Apr 23, 2020)

FrugalRefiner said:


> But we only get PMs if we log onto the forum.
> 
> Dave



Oops! Forgot. So much for my stroke addled brain.

Time for more coffee.


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## Lino1406 (Apr 23, 2020)

The said mixture is used on gold with CONSTANT stirring and a mild heating. I assume also potassium iodide in excess may be added. Mainly used for selective gold etching where a small excess of gold exists


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