Gold will not drop

[Swissgoldrefiner]

Dont follow my advice, as it's only theorically, never tryed, but
If it was me...i will add NaOH and good amount of water:
Most of metal hydroxyde have very very low solubility in water. So then i will have ONLY metal hydroxyde, like Copper hydroxyde, gold hydroxyde, etc...
At least at that point no more other salt than metal. Then i will dry it to have the salt in form of powder.
Then maybe dissolve it in dilute sulfuric acid hoping that i will dissolve Copper and that gold sulfate have maybe low solubility.
If both dissolve in dilute sulfuric, then i will add SMB, hoping that SMB will precipitate the gold from the gold sulfate.

 

[kurtak]

Just an update. Didn't want this thread to die.
I just received my beakers. So, I'll be moving the solutions to them. Also, between work and the crap weather we've had here I haven't been able to do anything. But, maybe tomorrow.

Sorry sleepyman1 but I did not see that you had posted updates to this thread after my last post until today

I don't have time right now but will try to get back to this - this weekend

For right now I have one question concerning the pics of the stannous tests you have provided

from the black solution - does the black - of the stannous test pictures - only show up after doing the stannous test - or is that black there when you put a drop of the solution only on the paper & before adding the stannous

To confirm what I am asking put two drops from that solution on your paper - then put a drop of stannous on only one of the two drops from that solution - take a pic & post it

I want to see the difference between that solution (on the paper) - one drop without stannous & one drop with stannous

Kurt

 

[kurtak]

Dont follow my advice, as it's only theorically, never tryed, but
If it was me...i will add NaOH and good amount of water:
Most of metal hydroxyde have very very low solubility in water. So then i will have ONLY metal hydroxyde, like Copper hydroxyde, gold hydroxyde, etc...
At least at that point no more other salt than metal. Then i will dry it to have the salt in form of powder.
Then maybe dissolve it in dilute sulfuric acid hoping that i will dissolve Copper and that gold sulfate have maybe low solubility.
If both dissolve in dilute sulfuric, then i will add SMB, hoping that SMB will precipitate the gold from the gold sulfate.

There is no need to do this

Right now there are only three possibilities of where his gold is

1) it is in his solutions
2) it is in the undissolved solids
3) some of it is in the solutions - some of it is in the undissolved solids

We just need to find where the gold is & then get the gold back - as gold

there is no reason to drop metals - as hydroxides - from solutions that have no gold in them

if a solution has gold in it (positive stannous test) we can get the gold back from that solution without first turning it to a hydroxide

if the gold is in (some) of the solids we will get that gold back out of those solids - without adding a bunch of hydroxides to those solids

what you suggest is taking a step backwards rather the going forward

Kurt

 

[sleepyman1]

This is from the black liquid. I don't know why it's green on the cloth. The green spot is before adding the stannous and the black spot is after adding it.

 

[Yggdrasil]

It don't look like gold to me.
But photos may be tricky in here.

 

[orvi]

I see a "maybe" gold (??), as Yggdrasil said, it don´t look as very golden-like stain. But it could be.
There is easy way how to find it out - and if it´s there, you will be able to collect it. It is a full procedure, but regarding your stannous tests - its unconclusive. I will run the full procedure - it is quite simple, only two lengthier steps are there (heating/cooling and filtration). Could be done in few hours and you will be done with it, either gold is or isn´t there.

Do not skip any step:

Take the mentioned solution in a beaker. That way you fill the beaker with liquid to max. 50%.

Heat it to around 70°C. Add sulfamic acid SLOWLY, only tip of a teaspoon at time and observe the reaction. Stir. Adjust the rate of addition to intensity of fizzing. If it stops fizzing or there is no fizzing, this step is done.

Cool the solution throughly to room temperature. Do not continue with hot/warm solution. You could add few ice cubes to speed the cooling process. This could also help to precipitate silver chloride from the solution.

If it has any kind of precipitate, filter it crystal clean. Rinse with minimal necessary water. If it contain silver, upon dilution it will immediately come out as cloudiness.

Assure that solution is strongly acidic (pH<1) - it seems like it standed somewhere for a long time and good portion of the acid could have been evaporated. If it isn´t, add some hydrochloric acid. 20-30 mL should do it. Addition of HCl could also help you to clear the cloudiness from AgCl.

After filtering, add SMB or sodium sulfite dissolved in water. This way you lower the possibility of precipitating some junk salts with gold (added volume of water help to dilute things a bit). Judging by the "positiveness" of the stannous test (and assuming its gold), maybe two teaspoons will be enough.

After addition, stir it well and close the beaker with watchglass/lid. You want that SO2 formed to stay in the vessel.

Let it sit overnight, and in the morning SLOWLY observe if some powder appeared on the bottom. Do not disturb the solution or shake the beaker, as you will swirl the powder and suspend it in solution again.
Solution is blackish-green. Light a LED on your phone or use normal torch - aim it on the bottom edge of the beaker - this will help you better see if there is any precipitate formed.

Precipitate of gold should be brownish in colour, and also could be nearly black if some fine particles formed.

If no precipitate appear, add one more teaspoon of SMB/sulfite dissolved in water, stir, let it sit overnight and observe again.

If again nothing precipitate from the solution, there is negligible or no gold.

 

[kurtak]

I see a "maybe" gold (??), as Yggdrasil said, it don´t look as very golden-like stain. But it could be.

IMO this is where his gold is (at least some of it - some of it may still be in his solid that did not dissolve in earlier steps)

As we know - a stannous test for gold will result in purple to black (depending on concentration of gold in solution)

To the best of my knowledge I don't know of anything else (metal or chemical) that will result in a black result with a stannous test

There is easy way how to find it out

Orvi -there is an easier way (then the rest of what you posted) to test to confirm gold

Take a "small" sample - couple ounces (or 50 ml) of the solution * put it in a small cup/jar/beaker & put some copper in it --- (Ph needs to be 1 or no more then 2)

If there is gold (in solution) the copper will cement the gold

Ovri - concerning the rest of your post - keep in mind that he has already added a HUGE amount of chem in his original attempt to recover his gold - he has basically made a HUGE chemical mess/soup

Therefore - personally - I would not add even more chem in trying to "recover" the gold

I would simply cement it with copper as a recovery step

Not saying chem recovery won't work - just don't need to complicate the recovery process

considering the "soup" he has made he is likely to have drag down anyway

Copper = one step with gold recovered --- copper (when done right) should give him back 98 plus gold (IF this is in fact where his gold is

At the very least - the above copper test is what I would do "first" to confirm gold

For the test I would use 10 (or 12) gauge wire

Kurt

 

[orvi]

IMO this is where his gold is (at least some of it - some of it may still be in his solid that did not dissolve in earlier steps)

As we know - a stannous test for gold will result in purple to black (depending on concentration of gold in solution)

To the best of my knowledge I don't know of anything else (metal or chemical) that will result in a black result with a stannous test

Orvi -there is an easier way (then the rest of what you posted) to test to confirm gold

Take a "small" sample - couple ounces (or 50 ml) of the solution * put it in a small cup/jar/beaker & put some copper in it --- (Ph needs to be 1 or no more then 2)

If there is gold (in solution) the copper will cement the gold

Ovri - concerning the rest of your post - keep in mind that he has already added a HUGE amount of chem in his original attempt to recover his gold - he has basically made a HUGE chemical mess/soup

Therefore - personally - I would not add even more chem in trying to "recover" the gold

I would simply cement it with copper as a recovery step

Not saying chem recovery won't work - just don't need to complicate the recovery process

considering the "soup" he has made he is likely to have drag down anyway

Copper = one step with gold recovered --- copper (when done right) should give him back 98 plus gold (IF this is in fact where his gold is

At the very least - the above copper test is what I would do "first" to confirm gold

For the test I would use 10 (or 12) gauge wire

Kurt

Yes. This would be easier to perform, you are right. I did not considered the already difficult mixture of chemicals he made. I meant it more like educational procedure which he will use also in the future when refining.

Going with copper would simplify everything, neutralize any excess oxidants etc

 

[FrugalRefiner]

When In Doubt, Cement It Out

Dave

 

[netgeek3]

If you were referring to sreetips, that was pins. Not fingers. His yield was a little over 22 gr but he paid $1k for the pins and used about 4 gallons of Nitric. Fingers are nearly all PCB. The gold is plated over copper (mostly) in a layer only a few atoms thick. Older material is a little better, but not by much.

Sorry, but this is incorrect. He purchase 6 lbs of trimmed fingers for $80 and obtained 11+ grams of gold. You can see the video here

 

[Martijn]

818 dollar is what i see in the video...so that was a loss at 75 a gram without processing costs.

 

[FrugalRefiner]

He purchase 6 lbs of trimmed fingers for $80 and obtained 11+ grams of gold.

As Martijn pointed out, according to the video, the price was $800.00 plus $18.00 shipping, not $80.00.

Dave

 

[sleepyman1]

Hey everyone I appreciate all the input. Kurt thanks a lot for hanging in here for me. I'm going to do what you suggest Friday or Saturday.

When I'm cementing, should it be cold or with heat?

 

[cejohnsonsr1]

Sorry, but this is incorrect. He purchase 6 lbs of trimmed fingers for $80 and obtained 11+ grams of gold. You can see the video here

The latest video I saw was pins at the price and yield I mentioned. I saw the video you referenced too. It was $800 plus shipping and the yield didn’t cover the cost of the material or processing.

 

[sleepyman1]

Is this what cementing is supposed to look like? This only after about 2 hours of letting the copper sit in the solution with heat.

 

[Martijn]

I never cement with heat. I don't think it has any advantage.
A little agitation is desirable.

About the color, looks like slimy silver and gold cement to me.
To be sure:
Ag and Pd dissolve in HNO3, gold in cold AR, And Pt in hot AR. Generally speaking.
I would dissolve the cement in those steps and test the different solutions with stannous to see what you have.

Pgm's in solution are highly toxic. Be extremely carefull and work clean and safe!!
If there's only a bit of pgm's, let the stockpot deal with it, or use it to gain experience in testing.
Refining pgm's is the next level of refining imo. Rocket science.
I just use the stockpot for any traces that might be present.
Never had a clear positive for pgm's with stannous though.

 

[orvi]

Is this what cementing is supposed to look like? This only after about 2 hours of letting the copper sit in the solution with heat.View attachment 48442View attachment 48443

Yes, this have the look I will expect for mixed Au,Ag,PGM cement. Need to be tested after cementation is done of course, but just looking at it, looks promising. Agitate the solution for better results. PGM slimes tend to stick to the copper and significantly slow the process of cementation.

 

[sleepyman1]

What's best practice in cementing? I tried leaving the copper in for a while and it began to dissolve. So, I stopped. How often should I pull out the copper and spray off the cement?

 

[FrugalRefiner]

See When In Doubt, Cement It Out.

Dave

 

[sleepyman1]

I put a about a foot of 1/2 inch copper tubing in the solution at 1ph to 2ph and no heat, using air to agitate. 95% of the copper dissolved and nothing dropped. The solution appears even blacker now.

So, at this point I think I need to move on to the solids (SMB). Maybe some gold is there?

How should I proceed at this point?

I'm thinking the gold just disappeared into the either, which sucks but at least I've learned a lot.