# Activated Carbon Stripping



## renatomerino (Jan 8, 2013)

Hello friends of the forum.
I hope to share this experience with you.
I am currently auriferous mineral leaching with cyanide solutions and absorbing gold with activated carbon.
The gold solution is very complex due to the presence of antimony in the solution.
Chemical reactions that have the gold and antimony are very similar using zinc powder, electrolysis or activated carbon absorption.
With adequate leaching values​​, I got gold in solution concentrations of 250 mg / lt. and 600mg/lt. antimony.
Loads of gold on activated carbon from coconut shell is 10 g / kg.
Analysis of gold on charcoal is very difficult because the values ​​obtained with atomic absorption are very erratic.
For this reason I think that an alternative control can burn coal and dissolve the calcine with aqua regia to determine the gold by precipitation.
Sorry for the translation using Google Translator, my original language is Spanish.


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## Lino1406 (Jan 8, 2013)

Antimony is soluble in hot H2SO4, gold is not
Antimony is burned by fire, gold is not


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## butcher (Jan 8, 2013)

renatomerino, 
Buenos dias.
I had no trouble your english it looked good.

I believe your plan to burn and do a wet assay would work, do you think you could just do a fire assay of the loaded carbon, directly using the appropriate flux?

I am not skilled in assaying or its math, but I can only see this telling you how much gold you are recovering on that run of material, I think also how well you took the sample from the carbon could also make a difference in how accurate the results.

You could do an assay of a batch of ore before, then after leaching, and also on the carbon, this may tell you how effective or complete your recovery is.

Thanks for letting us know what you have been doing in your spare time :lol: 

Lino1406 may have given some clues to finding a way to help seperate the gold from antimony in solution, although I am not familiar with cyanide, so I really am no help here either.
Maybe Lino also has some expierience with the cyanide and can help more in how to work in the sulfate, if this was an acidic leach I could help, but I cannot help with the cyanide.

Is the ore a sulfide ore, maybe you could help drive off some of the antimony in a roast of the sulfides before leaching, or in an acidic pre-leach?

Guess I am just not much help.
In my post here I just wanted a chance to say Buenos dias Amigo.

Hopefully GSP can give advise here He is skilled in doing assay, and also cyanide.


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## Traveller11 (Jan 9, 2013)

I'm curious, can the gold be separated from the carbon during melting of the gold by the fact that the carbon is incinerated? Would any of the gold be lost to the atmosphere?


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## butcher (Jan 9, 2013)

Carbon reduces metals in a melt, it takes oxygen (or oxides) from the metals, making CO2 gas, even some of the metals that will oxidize easily in a melt, like copper and metals above copper in the reactivity series will reduce to metal, many of the reactive metals would need carbon to be melted, carbon is added to a flux, or sometimes the metal is melted with coke or some other carbon source.

Gold does not oxidize easily even in a melt, (chlorides in the melt is a different story, and can oxidize some gold), but carbon would not harm the gold in a melt, besides maybe reducing some of the other metals in the melt with it.

Now I cannot say about the cyanide that may be involved here, some one with more knowledge of this would need to give safety precautions, or advice.


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## Lino1406 (Jan 9, 2013)

From what I understand, the cyanide in the system
can be destroyed. Seems also:
electrolysis can also separate.
cementation with copper.


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## renatomerino (Jan 9, 2013)

Hello Butcher and Lino
A major problem is the difficulty in burning charcoal coconut shell activated. (If problem not to mention the brand and type of coal).
I have tried to burn the charcoal with a gas torch and not burned.
I've seen some studies that mention medley with other coals softer but I finally found that is roasted with ease, when you grind 50 grams to 60 mesh, is mescla flour (7-8%), sodium nitrate (2%) and water to form pellets.
The mescla is placed on a plate on a kitchen.
During calcination removes large amount of antimony and finally calcined I treated with nitric acid and filtering.
The insoluble retained in the filter I have analyzed for gold by melting.
Friends of repeat analyzes give very similar results and the gold is very clean.
I'm happy to share this experience with you.


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## renatomerino (Jan 9, 2013)

I built a column to extract gold from activated carbon but I think the most important thing is to develop process control.
In the analysis of gold by atomic absorsion the result is usually lower.
I think it is advantageous when the analysis of mineral and activated carbon is used roasted.
In the first leaching tests, antinonio content in solution was 56 g / lt.
For this reason the precipitate obtained with zinc powder were less than 1% gold.
Currently the antimony content in solution is 0.3 g / lt. and allows me to use activated carbon.
I'm seeing how to analyze the antimony in solution with potassium bromate and tartaric acid.


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## renatomerino (Jan 9, 2013)

Lino.
I can not use sulfuric acid without performing legal procedures here because this is a precursor


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## renatomerino (Jan 9, 2013)

Lino1406 said:


> From what I understand, the cyanide in the system
> can be destroyed. Seems also:
> electrolysis can also separate.
> cementation with copper.


That metal?.


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## renatomerino (Jan 9, 2013)

Traveller11 said:


> I'm curious, can the gold be separated from the carbon during melting of the gold by the fact that the carbon is incinerated? Would any of the gold be lost to the atmosphere?


I have read that at least in the evaporation of solutions of auric chloride lost some gold.
Antimony chloride evaporates easily but as tartrate loss is smaller.
In developing the analysis of antimony digestion time of the sample with acid should be done carefully so as not to lose.
The activated carbon calcination is performed at low temperature and is difficult there volatilization losses.
Anyway 50grs calcination of carbon is very slow.
In Indonesia mentioned activated carbon calcination and fusion of the calcine to recover gold but do not provide details of the process.


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## SAMMS Adsorbents (Jan 16, 2013)

renatomerino said:


> Hello friends of the forum.
> I hope to share this experience with you.
> I am currently auriferous mineral leaching with cyanide solutions and absorbing gold with activated carbon.
> The gold solution is very complex due to the presence of antimony in the solution.
> ...




Have you looked at using other Adsorbents for Gold recovery? Our SAMMS Adsorbents have a higher capacity than Activated Carbon with faster kinetics.


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## butcher (Jan 17, 2013)

SAMMS Adsorbents,

Can you give me the chemistry of your absorbents, and how they are made, so I can make them at home, or understand more how they work, and what they are, are these carbon based reagents?

Are you here to help us learn or sell a product?
If you begin teaching and sharing information, I will consider you are here to learn and help us learn, but if you are just here for free advertising, you can pay for that somewhere else, or find a forum that allows advertisement, we do not allow Spam or spammers here.

Following your posts so far I can see only one intention, advertisement of a product, which you have given no clue as to what it is, as far as I know it could be a common reagent repackaged with a different name, and sold at a higher price, if your only purpose is to sell your product, or include the spamming of it into the forum, I feel I have only one option, If I see you sharing information, and not advertising, you could change my mind about pushing that Ban member button.


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## Gratilla (Jan 17, 2013)

Butcher (mi ol' mate :mrgreen: ), I think maybe you're being a mite tough on "SAMM". I see that you've been busy in other threads sending off spammers with fleas in their ears, (and I completely agree with those). But ... looking at SAMMS website, I think SAMM has a product that at least is worth a comparative look at here on the forum. [If this is against forum rules, though, I'll respect that.] At least he's not "spamming" in stealth mode.

Where I (personally) am coming from is that I have an interest in a newly licensed cyanidation startup now on its fifth leach and I (for one at least) would be interested in looking at anything that is more practical than the (activated) carbon in leach that we're currently using.

<With respect>


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## Gratilla (Jan 17, 2013)

Traveller11 said:


> I'm curious, can the gold be separated from the carbon during melting of the gold by the fact that the carbon is incinerated? Would any of the gold be lost to the atmosphere?



Yes; that's the whole point of firing loaded carbon.

And yes, if you're not careful.


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## butcher (Jan 17, 2013)

SAMMS Adsorbents, 
I do appologize, I just read the other thread, and see where you are looking for information, and have disclosed what your absorbants was based on, and was trying to learn and help others, and not here to just sell a product.

I did jump a little to hasty here.

I am not the sharpest tack in the box sometimes, many times I do not have time to read everything.


Gratilla, thank you for the post, I realized I had made the mistake after reading another post by Samms.


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