HCL Zinc reactions

[J.Najam]

Hello all,

Need a little help to understand the situation here I tried finding the correct procedure to use zinc precipitation in my solution, however, I couldn't find any article that could help me, so now I'm having a hard time understanding the relationship between zinc and HCL. Im using a Cyanide derivative close to the Eco-Goldex method, which is supposed to be very simple. To make the long story short :

Leach => adjust pH => add zinc => Decant solution => add HCL

Now what is happening is that the HCL seems to have only reacted with some zinc, I tried boiling the solution so that the remaining zinc could be attacked by HCL in the process, but this was to no avail and instead the zinc powder ended up being made into chunks/granules. I have no idea what this means now. I've attached pictures, how should I proceed with it from this point on? How will I know which Zinc particles have been treated with HCL and which ones I have to further process? Attached contains excess Zinc in HCL..

Thanks in Advance

 

[Yggdrasil]

Hello all,

Need a little help to understand the situation here I tried finding the correct procedure to use zinc precipitation in my solution, however, I couldn't find any article that could help me, so now I'm having a hard time understanding the relationship between zinc and HCL. Im using a Cyanide derivative close to the Eco-Goldex method, which is supposed to be very simple. To make the long story short :

Leach => adjust pH => add zinc => Decant solution => add HCL

Now what is happening is that the HCL seems to have only reacted with some zinc, I tried boiling the solution so that the remaining zinc could be attacked by HCL in the process, but this was to no avail and instead the zinc powder ended up being made into chunks/granules. I have no idea what this means now. I've attached pictures, how should I proceed with it from this point on? How will I know which Zinc particles have been treated with HCL and which ones I have to further process? Attached contains excess Zinc in HCL..

Thanks in Advance

Did you get a description from the producer?
I think the Zinc is used directly in the Cyanide solution, not sure.
But anyway Active Carbon is the preferred method of stripping the Gold from Cyanide based leaches.
And why didn't you go for straight Cyanide or Ferro/Ferri Cyanide, much less issues and usually much cheaper then these "green" concoctions.

Edit to add:
The reason of the trouble dissolving the Zinc may be due to the PMs passifying the Zinc so the HCl can't reach it.

 

[J.Najam]

Did you get a description from the producer?
I think the Zinc is used directly in the Cyanide solution, not sure.
But anyway Active Carbon is the preferred method of stripping the Gold from Cyanide based leaches.
And why didn't you go for straight Cyanide or Ferro/Ferri Cyanide, much less issues and usually much cheaper then these "green" concoctions.

Edit to add:
The reason of the trouble dissolving the Zinc may be due to the PMs passifying the Zinc so the HCl can't reach it.

Hello the ever-active responder, cheers to your prompt responses as always.

Well for the first question, I mentioned earlier as well that I managed to break down the entire thing on my own experiences more than the procedure that I was given by the producer. So I can say that I now know how to use the chemical for sure, only the last bit gets to me where zinc is involved.

Second, yes it is used directly to cement out the metals from the solution. However, the colour of the zinc powder has remained the same whenever I precipitated it until some kind of acid was used to kill the layers covering the sediment.

I don't know can activated Carbon attack and leach colloidal gold as well? For as far as I know they do a good job on even the extra super fine micron gold but I don't know if they'd do the same for gold in an aqueous solution. Never used it too.

I'm using Ram fingers for this process... With due respect I've never heard of PGMs being present in the fingers only sir.

 

[Yggdrasil]

Hello the ever-active responder, cheers to your prompt responses as always.

Well for the first question, I mentioned earlier as well that I managed to break down the entire thing on my own experiences more than the procedure that I was given by the producer. So I can say that I now know how to use the chemical for sure, only the last bit gets to me where zinc is involved.

Second, yes it is used directly to cement out the metals from the solution. However, the colour of the zinc powder has remained the same whenever I precipitated it until some kind of acid was used to kill the layers covering the sediment.

I don't know can activated Carbon attack and leach colloidal gold as well? For as far as I know they do a good job on even the extra super fine micron gold but I don't know if they'd do the same for gold in an aqueous solution. Never used it too.

I'm using Ram fingers for this process... With due respect I've never heard of PGMs being present in the fingers only sir.

I never said anything about PGMs, only PMs.
Activated Carbon or any other method do not touch collodial or any other sub micron Gold, since they are in a metallic state.
Only salts of Gold like Chloroauric acid, KAu(CN)2 or NaAu(CN)2.

You should decompose your CN species before adding acids, just to be sure.
Anyway, maybe a roasting of the powder before will let the HCl react and remove the Zinc.

Edit for spelling

 

[Yggdrasil]

Hello the ever-active responder, cheers to your prompt responses as always.

Well for the first question, I mentioned earlier as well that I managed to break down the entire thing on my own experiences more than the procedure that I was given by the producer. So I can say that I now know how to use the chemical for sure, only the last bit gets to me where zinc is involved.

Second, yes it is used directly to cement out the metals from the solution. However, the colour of the zinc powder has remained the same whenever I precipitated it until some kind of acid was used to kill the layers covering the sediment.

I don't know can activated Carbon attack and leach colloidal gold as well? For as far as I know they do a good job on even the extra super fine micron gold but I don't know if they'd do the same for gold in an aqueous solution. Never used it too.

I'm using Ram fingers for this process... With due respect I've never heard of PGMs being present in the fingers only sir.

Next, why don't you use the AP method, much easier and less pain to separate out the Gold, cheaper too.

 

[J.Najam]

I never said anything about PGMs, only PMs.
Activated Carbon or any other method do not touch collodial or any other sub micron Gold, since they are in a metallic state.
Only salts of Gold like Chloroauric acid, KAu(CN)2 or NaAu(CN)2.

You should decompose your CN species before adding acids, just to be sure.
Anyway, maybe a roesting of the powder before will let the HCl react and remove the Zinc.

Oh okay PM's, sorry my bad.

By decompose you mean completely evaporate any liquids at all right? I may use hot a hot water bath to break the remaining particles down and see how it works, did so last time though. Didn't try it because I really wasn't sure what these chunks were; first time with them.

I apologize, roasting of the powder? I didn't quite understand.

 

[J.Najam]

Next, why don't you use the AP method, much easier and less pain to separate out the Gold, cheaper too.

I am actually thinking of the same, however , issues with the same :

3percent peroxide:

If I use HCL + 3 - 12 % peroxide + air bubbler, it could take days or weeks and I don't have any place around my house to place an unsealed container. Inside we can't I guess and outside I fear the kids and pets all around.

30 percent peroxide:

If I use Boiling HCL 33% + 30% peroxide to dissolve the gold in one go, I won't be sure of all the gold going into the solution as this reaction makes the solution really dark and messy. However, since this does seem like the only option, so I think I'll go with this.

 

[Yggdrasil]

Oh okay PM's, sorry my bad.

By decompose you mean completely evaporate any liquids at all right? I may use hot a hot water bath to break the remaining particles down and see how it works, did so last time though. Didn't try it because I really wasn't sure what these chunks were; first time with them.

I apologize, roasting of the powder? I didn't quite understand.

Do your studies man.
Cyanides are decomposed by Heat 500+ Centigrade or UV (lamps, sunlight or so) or Oxidation by Hydrogen peroxide or similar.
Roasting means you heat it until it glows red.

 

[Yggdrasil]

I am actually thinking of the same, however , issues with the same :

3percent peroxide:

If I use HCL + 3 - 12 % peroxide + air bubbler, it could take days or weeks and I don't have any place around my house to place an unsealed container. Inside we can't I guess and outside I fear the kids and pets all around.

30 percent peroxide:

If I use Boiling HCL 33% + 30% peroxide to dissolve the gold in one go, I won't be sure of all the gold going into the solution as this reaction makes the solution really dark and messy. However, since this does seem like the only option, so I think I'll go with this.

Do not use strong Peroxide, it will dissolve the Gold.
In fact do not use Peroxide at all, only air bubbler and HCl, will take care of it.
The moment you have a green solution you have Cupric Chloride which do the job.
It should be done by a few days depending on temperature.
When time is an factor and Nitric is available one can use Nitric-Water 50/50.
It will be done in a short while, specially if you heat it to 80 Centigrade or so.
But make sure there are no kids and pets around the area and the fumes.

 

[J.Najam]

Do your studies man.
Cyanides are decomposed by Heat 500+ Centigrade or UV (lamps, sunlight or so) or Oxidation by Hydrogen peroxide or similar.
Roasting means you heat it until it glows red.

Again, with respect I had no idea this was a cyanide derivative until after I had purchased it. This wasn't told of before. Had I known I wouldn't have gone for it although it is eco friendly I have no experience and knowledge about cyanide. So even if i do decompose it, I wouldn't know about the salt residue if there may be any.

 

[J.Najam]

Reg

Do not use strong Peroxide, it will dissolve the Gold.
In fact do not use Peroxide at all, only air bubbler and HCl, will take care of it.
The moment you have a green solution you have Cupric Chloride which do the job.
It should be done by a few days depending on temperature.
When time is an factor and Nitric is available one can use Nitric-Water 50/50.
It will be done in a short while, specially if you heat it to 80 Centigrade or so.
But make sure there are no kids and pets around the area and the fumes.

Regarding the nitric and water procedure, I can take care of the surroundings as that can be done late at night with no one around.

What about the HCL and bubbler, does ir produce fumes too? I can most certainly do that. Also I have learnt the vinegar and salt method to recover just the foils.

I have 99% glacial acid, if i prepare a 50% vinegar solution with it and add salt to the solution do you think it could do the job too? Would it be considered environmentally safe because glacial acid had its own awful smell..

 

[J.Najam]

Anyway, maybe a roesting of the powder before will let the HCl react and remove the Zinc

Please clarify this as well, you mean filter the zinc ashes and roast them red hot in a crucible process?

If yes, then I might do the same after going ahead with one more HCL boil post filtration first. If that doesn't do the job then sure, ill do this.

Please confirm if you think this is okay before I could mess it up any further.

Thanks alot for your time here.

 

[FrugalRefiner]

I'll answer a couple of points.

The "eco friendly" products are only eco friendly in that they can ship them freely. Once you dissolve them, you're Woking with a cyanide solution.

The vinegar and salt technique is just creating HCl, with sodium and acetate ions in the solution. Just use HCl.

Dave

 

[Yggdrasil]

Reg

Regarding the nitric and water procedure, I can take care of the surroundings as that can be done late at night with no one around.

What about the HCL and bubbler, does ir produce fumes too? I can most certainly do that. Also I have learnt the vinegar and salt method to recover just the foils.

I have 99% glacial acid, if i prepare a 50% vinegar solution with it and add salt to the solution do you think it could do the job too? Would it be considered environmentally safe because glacial acid had its own awful smell..

Everything produce some fumes, but the HCl/air bubbler can be put into a bigger plastic container and be run only at night for instance.
And away from things that can rust.
Dave has answered the Vinegar part.

 

[Yggdrasil]

Please clarify this as well, you mean filter the zinc ashes and roast them red hot in a crucible process?

If yes, then I might do the same after going ahead with one more HCL boil post filtration first. If that doesn't do the job then sure, ill do this.

Please confirm if you think this is okay before I could mess it up any further.

Thanks alot for your time here.

There should not be any Zinc ashes, since Zinc do not get ashed.
No take the powder that don't react to HCl and heat it until it glows read for a few minutes, maybe 15-30 minutes.
Then hope that what ever have created a passifying layer is gone and try the HCl again.
Or just go directly to AR or HCl/strong Peroxide and dissolve it again and then precipitate by SMB.

 

[goldshark]

You may start vaporizing the Zinc, which is fairly toxic.Fume hood, or outdoors is highly recommended.

 

[Yggdrasil]

You may start vaporizing the Zinc, which is fairly toxic.Fume hood, or outdoors is highly recommended.

Yes, forgot about that, but as long as you don't breathe it directly it should be ok.
So maybe better to go directly to dissolve it in HCl/Bleach or HCl/ Peroxide and drop as usual with SMB.
If you do, test it with Stannous so you know the Gold is there.

 

[J.Najam]

I'll answer a couple of points.

The "eco friendly" products are only eco friendly in that they can ship them freely. Once you dissolve them, you're Woking with a cyanide solution.

The vinegar and salt technique is just creating HCl, with sodium and acetate ions in the solution. Just use HCl.

Dave

Although interesting, but Cyanide process is just a no-no. And yeah I was falling short of HCL and had some vinegar lying around, but anyhow thanks for the information. Shall fetch myself some HCL and get this done then.

 

[J.Najam]

There should not be any Zinc ashes, since Zinc do not get ashed.
No take the powder that don't react to HCl and heat it until it glows read for a few minutes, maybe 15-30 minutes.
Then hope that what ever have created a passifying layer is gone and try the HCl again.
Or just go directly to AR or HCl/strong Peroxide and dissolve it again and then precipitate by SMB.

I'm sorry I saw this today but had already done my process over the weekend. I did as I'd mentioned earlier:

Zinc granules immersed in Dilute HCl => Decant => Added boiling distilled water to let loose the particles held together => a fractional difference observed => Added HCl => 10 minute boil => unfortunately there was no GOLD in the solution at all

The solution turned a light brown transparent colour the same as we have our sulfuric acid drain openers at 93 % conc.

Added a little SMB to see if there is any reaction, fizzing was there but nothing more...

 

[J.Najam]

You may start vaporizing the Zinc, which is fairly toxic.Fume hood, or outdoors is highly recommended.

Ah yes, doing it outdoors with a mask and a DC fan pushing away the fumes