Help, I'm new in this area

[Oscarpastcer]

Hello, I'm Oscar, nice to meet you all I readed a lot of posts here, and I'm amaze all the information and help with other users, I want to congratulate the moderators and members.

Well, after that presentation, I want to talk about my problem. Recently I started to try to refine Au, I did my research and I found a process doable with the things I have, this process is Igoli, but a few days ago I finished the process and I couldnt precipitate any gold, in the samples there is gold, because the person who give me the sample used to work with the process of Hg, and find gold, and I want to change that process because the danger of that chemical.

I want to describe what I do.
First, I took the sample, and I leached with HCl diluated at 15 %(I used HCl about 37% of purity)
then I put about 0,2 lt of HCl diluated with 0,1kg of the sample
I stirring about 10 min and I added 50 ml of NaClO and after 20 min I added 5 ml od NaClO for 5 hours stirring
I separated the liquid/solid with a centrifuge and I found a solution colour green with yellow
This solution i put it in a vessel and put like 5 gr of metabisulfite (Na2S2O5)
And I wait all the night to precipitate, in the mourning I couldnt found any precipitate

These are my questions:
With my explication, is that ok? or did I do something wrong?

I realized I could find any precipitate because was a small sample, I gonna doit again with 1 kg, is there a posibility that the problem was the small sample?

How many grams of metabisulfite I need to add for 1kg of sample?

The method that I used to separated liquid solid, was a centrifuge, is that right or I need to change that method, like vaccum filtration?

The final question, are you recomended this process or you know any other?

Sorry for my english, but it is not my mother language.

Thanks for your response.

 

[eeTHr]

oscarpastcer---

Welcome to the forum.

If someone has an idea that they think might be of help, it would benefit you to list your approximate location in your personal settings, in the User Control Panel, so they might suggest process with chemicals that are more likely to be available in your area.

 

[samuel-a]

Welcome to the forum Oscarpastcer

I'm sure that eventually you will find your answers here, either by digging the archives or by asking questions.
It's obvious that you put much thought in your process and question but you left out the most essential part; What kind of material did you tried to process ?

please understand that providing details will help others help you.

Good luck .

 

[Oscarpastcer]

The material is soil, i dont know exactly what do you mean, with type of material, is Au there, because like I said in the post, the gold was extracting with Hg mercury.
Soil with a lot of water and other materials

 

[FrugalEE]

I did a google on Igoli and got this:

THEIGOLI MERCURY - FREE GOLD EXTRACTION PROCESS Sidney Mahlatsi, Senior Engineering Technician: Mintek - Small Scale Mining Division ABSTRACT; Mintek has developed a process called iGoli Mercury-free Gold Extraction Process that can be used to extract gold from 0.1 % gold concentrate to produce 99.90 percent gold product. The process uses a mixture of pool acid (dilute hydrochloric acid), bleach (sodium hypochlorite) and sodium metabisulphate to leach and recover gold.

So the chemical process is the same as used by quite a few board members.

FrugalEE

 

[carcrossguy]

You might want to make some stannous chloride to test if you have any gold in the solution. you need hcl and a bit of tin. I used 95% tin solder.

Some people say mercury is not very dangerous as long as you are knowledgeable and smart about it. Making a retort appears to be very easy.

http://www.goldnscrap.com/index.php?option=com_content&view=article&id=63:stannous-chloride-test-for-gold-platinum-and-palladium-presence&catid=25:scrap-gold-9k-24k&Itemid=20

 

[Barren Realms 007]

I did a google on Igoli and got this:

THEIGOLI MERCURY - FREE GOLD EXTRACTION PROCESS Sidney Mahlatsi, Senior Engineering Technician: Mintek - Small Scale Mining Division ABSTRACT; Mintek has developed a process called iGoli Mercury-free Gold Extraction Process that can be used to extract gold from 0.1 % gold concentrate to produce 99.90 percent gold product. The process uses a mixture of pool acid (dilute hydrochloric acid), bleach (sodium hypochlorite) and sodium metabisulphate to leach and recover gold.

So the chemical process is the same as used by quite a few board members.

FrugalEE

Your comment about pool acid is incorrect. It is regular strength acid.

 

[Oscarpastcer]

So, i dont have to diluate the acid?

 

[Barren Realms 007]

So, i dont have to diluate the acid?

I can't answer that question for you because I am not sure of what you are processing. I was just informing you that the acid sold in pool supply store is generaly 32%. Not diluted like you said.

Some pictures of what you are processing would help a lot.

 

[Oscarpastcer]

Ok, this monday ill take some pictures, I said diluate because the paper of mintek about igoli procees, said that, diluate at 15% the pool acid (HCl)

 

[Claudie]

I am just trying to understand here but, this is a soil sample you are trying to refine?

 

[Harold_V]

It is my opinion that you have processed way too little material to achieve a recovery. Unless you are working with extremely high grade ore (dirt), it's unlikely you will be able to recover gold profitably.

Lets look at it this way. I'm going to assume that the ore you have at your disposal contains a troy ounce of gold per ton. I'm also going to assume that you used as your sample, a pound (slightly less than a half kilo). Assuming it assayed an ounce/ton, and assuming you were successful in recovering all of the gold in your sample, you would have recovered less than ¼ grain of gold. It's highly unlikely that you'd be able to see it if it was there.

It would help tremendously if you could talk about the concentration of the ore in question, and how much you processed. You haven't provided enough information for anyone to form a reasonable conclusion.

I'd like you to keep in mind that processing ores with acid is rarely successful.

Welcome to the forum. I paid a visit to Venezuela back in '78. Beautiful country.

Harold

 

[Oscarpastcer]

Thank you all, for your valuable help and responses.
Harold, the concentration is around a troy ounce of gold per two pounds of soil.

I have a question, about this process, Igoli, does anyone had work with it? and if this process is really effective like the minetek say ?

I cant work with Hg, because here is very expensive, thats the reason.

By the way I'm recently got my grade of chemical engineer, about 2 weeks ago =)

And yes Harold, Venezuela its a beautiful country

 

[patnor1011]

If using mercury retort you will lose very small amount of mercury.

 

[eeTHr]

Oscarpastcer---

What is the exact nature of the material you are calling "soil"? Is it crushed rock from a mine, or acutally organic soil like would be in a garden? Or is it sands from a placer deposit?

That could make a big difference as to the best methods for processing it.

 

[Oscarpastcer]

Oscarpastcer---

What is the exact nature of the material you are calling "soil"? Is it crushed rock from a mine, or acutally organic soil like would be in a garden? Or is it sands from a placer deposit?

That could make a big difference as to the best methods for processing it.

The origin of the soil it is from a deposit with rocks, and it is crused, fine soil, tomorrow ill take a picture of the sample

 

[Oscarpastcer]

I am just trying to understand here but, this is a soil sample you are trying to refine?

Refine, no I'm trying to extract gold from the soil, i think my post is out of place here, could a moderator change my post to the proper area please?

 

[eeTHr]

Oscarpastcer---

OK, so what you really have is crushed rock ore. The term "soil" usually refers to the kind of dirt that people grow flowers and vegetables in, and contains lots of organics.

How fine is it crushed? Is it as fine as powder?

It would help if you include a few pieces of the original rock ore, when you post pictures of your material. The type of rock may help determine what would most likey be the best leach type.

 

[Harold_V]

Thank you all, for your valuable help and responses.
Harold, the concentration is around a troy ounce of gold per two pounds of soil.

Wow! That's' VERY good. Can you tell us how that number was achieved?

I have a question, about this process, Igoli, does anyone had work with it? and if this process is really effective like the minetek say ?

I'm sorry to say, all of my experience with ores came with cyanide and bromine. I am not a chemist, and am unable to make a fair judgment on the process.

By the way I'm recently got my grade of chemical engineer, about 2 weeks ago =)

Congratulations! I commend you for the effort it must have taken.

Please give us more information on your project so we can gain a better understanding. You've already mentioned posting pictures. They should help considerably.

Harold

 

[Claudie]

You stated that the concentration is around a troy ounce of gold per two pounds of soil. If you are doing a 1kg sample (which is what you asked about) that would work out to about 2.2 pounds of material. So that should mean there is over one ounce of gold in your sample.

May I ask if you purchased this sample from a trusted source or have you seen any assay results? Please forgive me if I am asking unusual questions, I am just trying to understand for sure what you are dealing with. With an ounce of gold in a 1kg sample, I am thinking you should be able to find it. Maybe my math is wrong or maybe I am misunderstanding something.