# Eco Goldenex.. I cannot cement out my gold with SMB



## kearneydude1968 (Dec 27, 2021)

Hello everyone
I am new to this forum and gold recovery.
I bought the Eco Goldenex package with the stripper and the zinc powder/ph level tabs.
I went through all the steps from stripping the plated gold off of the pins, to lowering the PH level before I added my zinc powder. We did this several times to make sure we got most of the gold out of solution.
Then we filtered it and then using a electric burner we heated up the acid of muriatic acid and some nitric acid. Maybe used 400 milliliters to maybe 10 mls of nitric. I did add a bit more during the process to make sure we made AG.
That way I would be sure my gold went into solution. I also added a bit of concentrated sulfuric acid to get rid of the lead. Just a bit.
Ok so after all of that I got it up to temp and let it go for a few hours.
I let it cool and dropped some ice shavings in. I used urea to denox it and let it sit. Later I filtered the whole thing and put SMB in the solution. It fizzed a lot and I stirred it and came back a few hours later…. I got no color change. No cement gold on the bottom…. So I added more SMB and stirred and came back five hours later… nothing changed. The SMB always fizzes when it is added. So I thought maybe I had to much nitric acid in the mix and maybe I needed to add more urea….. over the weekend I’ve added probally 1/2 cup in total and then later put in SMB and still no change.
Any advice?


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## kearneydude1968 (Dec 27, 2021)

Btw I also dropped the PH with each zinc drop between 1 to 4 and used deluted distilled water and concentrated sulfuric acid. Small amounts at a time.


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## FrugalRefiner (Dec 27, 2021)

Start by reading the Eco-goldex CYANIDE Leach thread. There are several other threads that deal with eco-goldex (which you can find by using the search function at the top righ corner of the page.

Dave


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## Frigidigital (Dec 27, 2021)

Did you test the solution with Stannous Chloride?


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## Yggdrasil (Dec 27, 2021)

It may also be interesting to know how much plating you dissolved.
One ram stick one hundred?
There may be too little to see or maybe waay to much nitric.
Who knows?


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## Martijn (Dec 28, 2021)

You made enough Aqua Regia to dissolve 10 grams of gold. 
Urea does not help in any way. 
Sulfamic acid does. 
Or use the liquid to dissolve more gold with. Or let a couple of grams of copper dissolve if you don't have more gold to dissolve. 
It will eventually cement out the gold.


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## kearneydude1968 (Dec 28, 2021)

Martijn said:


> You made enough Aqua Regia to dissolve 10 grams of gold.
> Urea does not help in any way.
> Sulfamic acid does.
> Or use the liquid to dissolve more gold with. Or let a couple of grams of copper dissolve if you don't have more gold to dissolve.
> It will eventually cement out the gold.


Thank you for your help. I’ll check back with you after I use the sulfamic.


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## Martijn (Dec 28, 2021)

Before you go and add a liter without any effect, check how it's supposed to be done to get the desired result. And when you can stop. Know the signs.
I have it, but never used it, because i didn't need to. 
I believe its done warm or even hot, (check this yourself first) and very slowly to avoid a boil over. 

Oh, and how much did you dissolve? From how much pins? Did you weigh the precipitated gold? 

Good luck and be safe. 

Martijn.


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## joekbit (Jan 22, 2022)

Knowing what to expect and how much it will hold , in my opinion is your first starting point. So run some pins the old fashion way to determine how much to expect.
How much will the gold x hold?
You could determine that with say 100 mils of gold x and some gold powder (weighed) Add it to the solution slowly until no more dissolves and weigh what's left. Now you know how much the gold x will hold. You have your base lines to work with. 

A saturated solution will always give up the Au easily. 
I've looked at the gold x. Have a friend who uses it. They recommend saturating the solution. give it all it can take before you attempt to drop the gold.


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## orvi (Jan 22, 2022)

kearneydude1968 said:


> Thank you for your help. I’ll check back with you after I use the sulfamic.


As we do not know how much gold you have in solution, we cannot guess how much free nitric is left in the soup.

Sulfamic works hot on nitric/nitrate, start adding SLOW when solution is more than around 70-80°C - this eliminate the possibility of runaway reaction. LOTS of gas will be emitted from the solution if there is portion of unreacted nitric = lots of fizzing = > prepare big container (at least 2 times the volume of the liquid).

Sulfamic will fizz also at room temperature when added to AR, but this is accounted mostly for the reaction of NOCl or nitrous acid species present (nitrogen in +III ox. state), which react more quickly, liberating nitrogen out of the solution. Eventually, all the nitric undergo reactions with HCl, producing Cl2 and NOCl predominantly, and this will slowly eliminate whole bulk of nitric/nitrates from solution. 

This is also the reason why urea fizz, when added to AR solution. Not killing the nitrates/nitric, but only nitrous species evolved from HCL and HNO3 reaction. Urea nitrate is quite stable compound  if you do not heat it or disturb it - then it could explode.


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## macfixer01 (Jun 9, 2022)

kearneydude1968 said:


> Hello everyone
> I am new to this forum and gold recovery.
> I bought the Eco Goldenex package with the stripper and the zinc powder/ph level tabs.
> I went through all the steps from stripping the plated gold off of the pins, to lowering the PH level before I added my zinc powder. We did this several times to make sure we got most of the gold out of solution.
> ...




Did you skip a step or just not list it? I’m confused why you would go right from dropping gold with the zinc powder directly to using AR (aqua regia) which will dissolve both the zinc and the gold? Why wouldn’t you use only HCl first to dissolve away the zinc as soluble zinc chloride? Then you could filter it and collect only the impure gold powder to dissolve using AR, neutralize with sulfamic acid, and drop the gold with SMB.


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