Iodine leach

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kurtak
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Re: Iodine leach

Post by kurtak » August 2nd, 2020, 11:37 am

Ok - so recently I have had a couple people tell me they have "several" buckets full of black sands & asked if I could recover the "traces" of gold in the sands - these would be the traces remaining in the sands "after" other concentration methods (running the sands through a gold spinner &/or over a shaker table)

we know that even a shaker table or gold spinner does not get all the gold from black sands

So I am just wondering if iodine/iodide leaching the black sands would work to recover the traces of gold in the black sands ?

Hopefully Deano can chime in on any pros/cons

out the gate I can likely get my hands on 10 - 15 buckets full & if it's a viable leach method I can likely get who knows how much more - being as where I live it's just a matter of putting the word out to get more

Kurt

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Re: Iodine leach

Post by Deano » August 2nd, 2020, 7:42 pm

Most gold in black sands is present as free gold particles, it is rare for any quantity of gold to be locked up in the sands themselves.

As most of the black sands cons have been recovered by sluicing you are looking to gravity recover the gold by a system which is at least as efficient as a sluice system.

Most, if not all, of this free gold can be recovered by use of a table, provided the feed has been properly sized and the table is operated correctly, I had a section on tabling on my earlier thread.

The amount of gold which is not recovered by a properly run table is small enough that it is only viable to use cyanide as a leach system to recover this gold.

You can certainly recover any fine residual gold from table tailings with most gold leaches but it usually is not viable to do so due to the cost of running these leaches.

Most acid based or high redox leaches will also have a lot of the leach components lost in the digestion of the iron sands themselves, so you are looking at low redox or neutral to alkaline based systems to minimise reagent consumption.

My first approach would be to set up a properly made Wilfley type table and run feed which has been well sized, it is impossible to recover all < 50 micron gold from a coarse feed which has a higher inertial component.

Deano

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DNIndustry
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Re: Iodine leach

Post by DNIndustry » August 11th, 2020, 6:00 pm

Lou wrote:
June 2nd, 2020, 3:54 pm
I2 leach can also be used with organic solvents, including DBC.

The gold is recovered by boiling wherein the iodine sublimates, AuI3 decomposes and metallic gold left behind.
I previously did this alot both KI and NH4I.
KI is very acidic is very hungry for base metals. NH4I is nearly neutral easy virtually no base metals

1 gallon of this KI/I3 (depending on I2 concentration) can hold upto 4 ozt of Gold

Lou..
I believe that unless you use a some form of liquid cooled coiled condenser you are going to loose values. I know this for a fact. I have lost a decent amount For reference they use iodine to refine Titanium, Niobium, Halfnium, And a bunch of other metals as an Iodine gas.
Chemical Mass transport
Van Arkel Deboer process

Any apparatus ideas?

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DNIndustry
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Re: Iodine leach

Post by DNIndustry » August 11th, 2020, 6:04 pm

Yggdrasil wrote:
July 5th, 2020, 5:29 pm
The HCl or Nitric wash is to clean the Iodine after it have been dropped out of the dirty Iodide solution.
The document uses the phrase "mineral acid" so I guess HCl might be the goto solution for most of us.

I'm going to test Ammonium Iodide because then I'm not confined to buy new KI.
I will then just generate the NH4I needed by adding NH4OH and H2O2 to the I2.
That is my plan at least :wink: :mrgreen:

Look back through my old posts. You will find alot of what you will need.

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DNIndustry
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Re: Iodine leach

Post by DNIndustry » August 11th, 2020, 6:19 pm

House hold nh4oh is not the same.
A
Has other ingredients if its the cleaner.
Tech grade NH4OH is 28 to 29%. 1 gallon will last for ever

Make sure to follow directions on lingering smell if it occurs. Add h2o2 as delineated.

I believe I used sulfuric for the regenerating. Have to look back.

Hydroxylamine hcl is on eBay.

Don't forget you can do palladium platinum and rhodium as well.

I advise against the oxalic acid drop ....nano spherical metalic gold that glazes your beaker.

You will know if you cleaned the mud well when you melt an purple or blue smoke comes out. Your losing gold if so.

Lou
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Re: Iodine leach

Post by Lou » August 12th, 2020, 11:34 am

Do not add ammonia (ammonium hydroxide) to elemental iodine!!
Like chemistry? Try http://sciencemadness.org/talk

All that glitters is not gold. Occasionally it's rhodium :)

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Re: Iodine leach

Post by Yggdrasil » August 12th, 2020, 11:48 am

Hi Lou.
Can you please elaborate a bit more?
Best Regards PoA

My Primary language are not English so language errors may occur, please do correct me whenever needed :-)

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Re: Iodine leach

Post by patnor1011 » August 13th, 2020, 3:09 am

Yggdrasil wrote:
August 12th, 2020, 11:48 am
Hi Lou.
Can you please elaborate a bit more?
It will produce highly unstable explosive nitrogen triiodide. That stuff if dried can be set off with a feather.
I do not mind a bit of base metals in solution or to recover iodine after every leach and to start over. It is more labour-intensive but well offset any hazard of trying to use iodine with ammonia.
I like the peace of mind when doing my stuff and as little hazard or problems as possible. To this day I am scared to go close to concentrated sulfuric or lye and I do not plan to add iodine leach to that list so no ammonia for me. :mrgreen:
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Re: Iodine leach

Post by Yggdrasil » August 13th, 2020, 3:43 am

Aah I rest my case.
There was no such mention in the patent document.
Can this be counteracted by adding peroxide first or using a lower concentration ammoniun hydroxide?
Best Regards PoA

My Primary language are not English so language errors may occur, please do correct me whenever needed :-)

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DNIndustry
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Re: Iodine leach

Post by DNIndustry » August 14th, 2020, 1:58 pm

The patent doesn't give the warning Lou does.
It expects you to follow the directions explicitly. If you follow them it works wonderfully.
Remember your reading a patent. Pretty sure the patent office reviews and checks the claims very carefully.
They are not going to publish what not to do
Ammonium iodide it self is not flammable.

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Re: Iodine leach

Post by vav » October 10th, 2020, 3:31 pm

HI ALL

how do you exactly handle with rinsing water...do you evaporate ...or precipitate as main liquor...or use as another part of source of new batch
Thanks for your imput

vav

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Re: Iodine leach

Post by vav » November 4th, 2020, 8:32 am

To DNIdustry
I have tried to send you PM but its stucked in Outbox don't know why,than I have to posted here

Amonium Iodine problem
Sent: November 3rd, 2020, 8:21 pm
From: vav
Recipient: DNIndustry

Dear sir,

I am not completly biginer,some methodes like AP,AR,drop with even oxalic acid, Sulfuric cell etc. goes well for me and I alreday recovered little more than 110gAu after melting but
I would like to ask you to help me with my NH4I composition.Regarding patent this should be clear or whiteish solution.
I read all available wires here in GFR about this topic as well as patents you mentioned and see some videos...but
even when I follow the amounts of ingredients exactly I am not able obtain NH4I as clear solution,thus I cant add suplemental Iodine to form final etchin solution
I took for first try all in 1/10 ratio.
50ml DI H2O add 35.1g Iodine crystals
start stiring at magnetic stirer
add 4.7g H2O2 30%
stiring in 1 min. slightly red color
add 9.7g NH4OH 25% in 2ml portions by pipet,
after 3rd additons no more clear solution only dark brown even after all 9.7g spent
continuos stiring didn help even after 3 hours
and there is still undisolved residue of Iodine at the botom of beaker.
Even in this state without adding last portion of 10g suplemental iodine
the solution strips my finger from old ISA slot in less than minute,but I would like to understund what I did wrong especialy when NH4OH and Iodine is envolved.
ALL ingredients are lab. grade from Lachner company.
I would like to use this method because some mine material is not suitable for sulfuric cell like smal connectors with pins traped in plastic which cause problems in sulfuric...
Thank you in advance,and hope you will spend some time to help me
Jan
vavouk@volny.cz

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FrugalRefiner
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Re: Iodine leach

Post by FrugalRefiner » November 4th, 2020, 8:41 am

vav wrote:
November 4th, 2020, 8:32 am
To DNIdustry
I have tried to send you PM but its stucked in Outbox don't know why,than I have to posted here
Jan, your PMs stay in your Outbox till they are opened by the recipient. Then they move to your Sent folder. It's not an error or a problem. It's just the way the PM system works.

Dave
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vav
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Re: Iodine leach

Post by vav » November 4th, 2020, 11:01 am

Tkanks a lot Dave
didnot remember this behavior of PM, 3 years ago I used last one

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