Patent # 3,957,505 Iodine-Iodide Leaching

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LeftyTheBandit

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Patent # 3,957,505

I have attached the pdf of the patent for easy familiarization.



1. A process for extracting gold from gold bearing material which comprises:
treating the gold bearing material in an aqueous solution consisting essentially of iodine and a water soluble iodide salt to dissolve gold from said gold bearing material; mixing a reducing agent with said aqueous solution to reduce dissolved gold iodide salts to gold metal and precipitate said gold metal in substantially pure form from said aqueous solution; Removing precipitated gold metal from said aqueous solution; and adding an oxidizing agent to said aqueous solution to thereby restore said solution to substantially its original condition for dissolving gold from further gold bearing material.


4. The process of claim 1 in which the reducing agent is sulfur dioxide.
Question #1
Would I be able to use SMB and not effect the solution negatively?


5. The process of claim 1 in which the reducing agent is an alkaline solution of hydroxylamine.
Question #2
Does this mean hydroxylamine can be acidic or base, or does it mean depending on what you are processing, the solution could be acidic or alkaline due to the make up of the media your processing?

6. The process of claim 1 in which the reducing agent is an alkaline solution of hydrazine.
Question #3
Does this mean hydrazine occurs in both an acid state and a base state and if so you must use the alkaline version?


9. mixing a reducing agent with said aqueous solution in the presence of buffer to reduce dissolved gold iodide salts to gold metal and precipitate said gold metal in substantially pure form from said aqueous solution, said buffer being capable of supplying hydroxyl ions during the precipitation of the gold metal;
Question #4
This makes it sound as if the buffer is used to supply ions and not keep the pH stable. My understanding of buffers is near zero.


13. The process of claim 9 in which the buffer is dibasic ammonium phosphate.
Question #5
I looked up buffers at a chemical supply house and all buffers are named by the pH level they are used for, non of them are identified by an actual name as quoted here. It appears the buffer is being used not to control the pH but to offer Ions that are lost during reducing and regeneration of the stripping solution. Is this what buffers are for or is this the way the inventor keeps his solution active longer?

mixing hydrazine and sodium hydroxide to said aqueous solution in the presence of ammonium acetate to reduce dissolved gold iodide salts to gold metal and precipitate said gold metal in substantially pure form from said aqueous solution;
Question #6
Is the ammonium acetate being used as a buffer? I believe this is a secondary method of precipitating other than using sulfur dioxide gas, which I would rather use because of it's simplicity but I noticed sodium hydroxide which is alkaline being used here which may be favorable by not adding sulfur to the equation.

Salts will build up after repeated cycles and reduce the effectiveness of the iodide-iodine stripping solution with respect to speed and capacity after repeated additions of H + and OH - ions required for the various reactions of the process. This build up problem is overcome in a preferred embodiment of the invention by adding a buffer to the solution which serves as a source of both H + and OH - ions. The use of a buffer with pH's spanning the pH values (about 5 to about 9) at which H 2 O 2 oxidizes I 3 - and NH 2 OH reduces AuI 4 - permits the same solution to be used repeatedly without the degree of salt buildup which would otherwise occur if acid and/or alkali is employed to adjust acidity. Salts of weak acids and a weak base, for example, store both H + and OH - ions in solution in such a manner as to render them available to hydroxyl amine (NH 2 OH) and hydrogen peroxide (H 2 O 2 ), respectively.

Question #7
Does this mean I can use H2O2 instead Hydroxyl amine or are they to be used together to give the effect required?

The following equation shows the conversion of dibasic ammonium phosphate to ammonium hydroxide and monobasic ammonium phosphate in the presence of water, thereby serving as a source of both H + and OH - ions.

(NH 4 ) 2 HPO 4 + H 2 O ➝ NH 4 OH + NH 4 H 2 PO 4

the gold recovery process of the invention can best be seen by reference to the following series of reactions:
Iodine, I 2 , in an aqueous solution of potassium iodide, KI, is present as the tri-iodide anion:

I 2 + KI ➝ K + + I 3 +

the reaction between gold and tri-iodide anion can be written as follows:

3K + + 3I 3 - + 2Au ➝ 2KAuI 4 + K + + I -

gold in the form of gold hydroxide, Au(OH) 3 , or auric oxide (Au 2 O 3 ), is formed as a yellow-to-brown precipitate, very insoluble in water, when an alkali hydroxide is added to the potassium auric iodide material. Gold itself rather than gold hydroxide is precipitated in the presence of a reducing agent:

KAuI 4 + 4NH 2 OH + OH - ➝ Au ↓ + 2N 2 ↑ + K + + 4I - + 5H 2 O
Question #8a
I can not read scientific notation yet and I feel the answer is here about why they want a buffer. I want to use SMB, what would you suggest I use as a buffer if I am using SMB and peroxide in my reactions?

Question #8b
dibasic ammonium phosphate appears to be suggested as a buffer that serves both functions if I read it right. Unfortunately this stuff is almost $85 per 100g and if there is a better (cheaper) buffer that jumps out could anyone suggest?
 

goldsilverpro

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The guy that owned Bayside refining (the owner of the patent) later became my partner in another refining venture. I never tried the process but was told that it worked very well.

Lots of questions. The Example in the patent seems to be very straight forward. Why not try it as stated and then worry about the details later? Many of your questions will probably be answered by actually doing it.

The SMB would probably work, for awhile, but the whole idea is to be able to use the stuff over and over, as a closed loop. With SMB, you would be adding extraneous ions to the solution and I would imagine these would eventually gum up the works.
 

LeftyTheBandit

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Noble Metals Recovery said:
Thanks for posting the pdf for the patent. Regarding using Sodium Meta Bisulfite as a reducing agent, the patent states on page 4, line 25 that it can be used.

Yes, I noticed this as well but I'm concerned that if I use SMB it would alter the buffer I need to use. I'm setting up a basic experiment with out the buffers to see how much I can process without buffers. Once it gets bogged down I will just recover the I2 and start over.

The problem is that the potassium Iodide gets used up so even if I recover the Iodine I need to keep buying potassium Iodide.

I need to find a way to make KI so I can create it with my iodine.

I'm listening to GSP. I'm going to do a bunch of small scale experiments so I can get a feel for it and perhaps even figure it out on my own. I just hope I don't create some unknown waste crystals that are explosive or something.
 

Irons

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Noble Metals Recovery said:
Why not use one of the buffers? Ammonium acetate doesn't seem like it's hard to get.

You can always make your own from white vinegar and household ammonia.

All you have to do is add the vinegar and ammonia to the stripper. They are both about 5% solutions, so, it's not too difficult to calculate how much to add for a given volume of stripper.
 

LeftyTheBandit

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Irons said:
Noble Metals Recovery said:
Why not use one of the buffers? Ammonium acetate doesn't seem like it's hard to get.

You can always make your own from white vinegar and household ammonia.

Thank you Irons and Noble Metals.., I will make this my 1st buffer after I try my non buffer mix and will compare the two.

I thought ammonia and Iodine were a bad mix?
 

Oz

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Typically they are, which makes an answer to that all the more important before you proceed.

In very general terms (not being a chemist) the addition of iodine, alcohols, or ammonia needs to be done with great caution.
 

Irons

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LeftyTheBandit said:
Irons said:
Noble Metals Recovery said:
Why not use one of the buffers? Ammonium acetate doesn't seem like it's hard to get.

You can always make your own from white vinegar and household ammonia.

Thank you Irons and Noble Metals.., I will make this my 1st buffer after I try my non buffer mix and will compare the two.

I thought ammonia and Iodine were a bad mix?

It's not a problem in an acidic medium. Just mix the ammonia and vinegar together and then pour it into the stripper, if you choose.
 

Irons

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LeftyTheBandit said:
Thank you Irons, for clearing that up.

Once I filter the solution does it need to stay acidic?

A pH of 4 or 5 should be fine. The danger in mixing free Iodine with Ammonia is when the solution is rather dilute and basic. I have a scar on the palm of my right hand from 40 odd years ago when a glass Litmus Paper tube full of water an a few milligrams of Nitrogen tri-iodide detonated in my hand. I thought it would be safe by storing it in water but I was wrong.
This is not a process for an amateur who doesn't understand the implications of what is going on. A few hundred milligrams will put you in orbit.
 

LeftyTheBandit

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Irons said:
a few milligrams of Nitrogen tri-iodide detonated in my hand. I thought it would be safe by storing it in water but I was wrong.
This is not a process for an amateur who doesn't understand the implications of what is going on. A few hundred milligrams will put you in orbit.

:shock: I have already paid dearly for stupidity in the past, perhaps this buffer solution may not be in MY best interests. Being an amateur and having no idea of what is going on in this solution, I'm glad I asked the question before preceding. Thank you big time Irons! :|
 

Irons

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LeftyTheBandit said:
Irons said:
a few milligrams of Nitrogen tri-iodide detonated in my hand. I thought it would be safe by storing it in water but I was wrong.
This is not a process for an amateur who doesn't understand the implications of what is going on. A few hundred milligrams will put you in orbit.

:shock: I have already paid dearly for stupidity in the past, perhaps this buffer solution may not be in MY best interests. Being an amateur and having no idea of what is going on in this solution, I'm glad I asked the question before preceding. Thank you big time Irons! :|

You did the right thing in asking questions. My pain is your gain.

What I worry about are the peckerwoods that go charging into a process and end up hurting themselves and possibly others then come back here and try to blame us.

BTW, the only other casualty besides me was the Home Room instructor. He was leaning back in his chair and fell backwards, hitting his head on the Black Board. I was in the penalty box for a few days. He and the Principal ware not happy.
 

butcher

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Why study & read? learn before we get gold, we just want to know how to do it, just tell me how. :roll:

IRONS QUOTE:
detonated in my hand. I thought it would be safe by storing it in water but I was wrong. :x

A few hundred milligrams will put you in orbit. :shock:

peckerwoods that go charging into a process and end up hurting themselves and possibly others then come back here and try to blame us. :!:

maybe we should think and study some :?:
 

Palladium

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It's funny how in todays world everyone wants instantaneous results without the hard work.
Sort of reminds me of the pharmaceutical companies and how they have a pill for every ailment known to man.
 

butcher

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lefty I think you were wise to study and follow advice on this project.

those make you better or feel better instant pills are like instant one post answers how to refine gold lessons, both lead to more problems.
 

DarkspARCS

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Palladium said:
It's funny how in todays world everyone wants instantaneous results without the hard work.
Sort of reminds me of the pharmaceutical companies and how they have a pill for every ailment known to man.

Currently, I'm ailling for some GOLD!!!!!... I'm gonna go down to Rexall, and see if they have any gold extraction tablets.... :mrgreen:
 

glondor

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I do have 4 gold extraction machines here at home. Each extracts to a varying degree. Of the four the most effective is the wife unit who likes to shop..
 

DarkspARCS

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glondor said:
I do have 4 gold extraction machines here at home. Each extracts to a varying degree. Of the four the most effective is the wife unit who likes to shop..
:lol: :lol: :lol:

:shock:

OMG!... wife units extract efficiently!? You must be using a higher percentage than I am... I have a wife unit too and the extraction rates usually only trickle. That's at room temperature though. Perhaps if I added a little heat ....
 
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