[geubrina]

Hi, anybody can help me so I can demonstrate of how to extract copper ore. As the Lab result, the ore has copper, gold and silver content.

[LQ43]

Google "extracting copper from ore"

[hmx9123]

It's generally done with cyanide now a days.  I wouldn't want to do that.

[Alpha-Omega]

The above response is accurate and correct.  However, you could use this process (no cyanide-sulfuric acid and zinc chloride) as demonstrated at this link:

Nice step-by-step extraction procedure with animation that demonstraes the analytical techniques:

http://ch185.semo.edu/copper/lab6intro.html

This will give you your copper...


Thiosulphate leching is anoter method: 

http://sci.ege.edu.tr/~jfs/chem/06/Silver_Extraction_from_Argentite_by_Thiosulphate_Leaching.pdf

[THC]

This is maybe completely off, but my teacher talked about elektrochemistry in this context? You make a elektrochemical cell with Cu2+ on your ore in half-cell and another more noble metal + ions in the other half-cell.

[Arkcon]

This is maybe completely off, but my teacher talked about elektrochemistry in this context? You make a elektrochemical cell with Cu2+ on your ore in half-cell and another more noble metal + ions in the other half-cell.

True enough, the final step in the purification of copper for especially electrical use is electrochemical.  More noble impurities accumulate as an anodic slime.  The input copper for electrorefining is usually >99%, however.

[Arkcon]

'Course, if you're bored with mundane chemical purification, there's always bacterial methods {clicky}

[geubrina]

Hi everybody, I found out that there is magnetic element in the ore, so I heated the pulverized ore and then manually remove it with magnet.
The leftover should be minus iron/nickel content, right?

Then can I proceed with the aqua regia?

[Arkcon]

If you add conc. sulfuric acid, with either air or oxygen gas bubbling, you can quantitatively react the copper, leaving more noble metals behind.  Aqua regia will simply dissolve everything (usually), once you've done that, then what will you do?

[geubrina]

If you add conc. sulfuric acid, with either air or oxygen gas bubbling, you can quantitatively react the copper, leaving more noble metals behind.  Aqua regia will simply dissolve everything (usually), once you've done that, then what will you do?

You said I can react the copper quantitatively; is that mean not all the copper but most of the copper will react? As per your prediction, how much of the copper will be left behind?

Regarding the Ag and Au, I think Ag is more reactive to HCl compare to Au, so, maybe I will put the left behind metals into HCl slowly and let the Ag react first with the HCl. And maybe, I have to wash this several times.

After that, what should I do with the left behind Au?

[Arkcon]

You said I can react the copper quantitatively; is that mean not all the copper but most of the copper will react? As per your prediction, how much of the copper will be left behind?

No, that means over time, all of it does, and the soluble portion is valid for quantitative analysis for copper.

Regarding the Ag and Au, I think Ag is more reactive to HCl compare to Au

Really?  Pure solid silver is going to react with hydrochloric acid, to produce solid, insoluble silver chloride, which will shield the mass from further action.

This is a common beginners problem with quantitative ore analysis.  The beginner attitude of "I'm just going to soak it all in aqua regia, the strongest acid of all, and all that I want will dissolve." doesn't always work.  Conc. nitric doesn't always work -- it may passivate ferrous alloys, blocking further reactions.  Hydrochloric may form an insoluble crust with silver, lead, and mercury, even as other reagents reduce them to free metals.  Since aqua regia is both, either or both effects (or perhaps neither -- like I said it may work) may occur.  Your ore sample may require pre-digestion with hydrofluoric acid to dissolve enough of the rocky matrix, even though hydrofluoric is a weak proton donor.  You should be able to read up on these particular topics in ore processing for quantitative analysis and the need for these procedures.

There are other metallurgical manipulations for you to review, cupelation is still practiced, electro-refining has been mentioned before in this tread.  As has cyanidation, and I threw in bioleaching just for the fun of it.

[geubrina]

Anyway, I think I have get rid off 2 element which is not gold or silver.
First by magnet, I have take out the iron, and
Second, the copper.

Now, how do I separate the gold and silver? I read that use the salt, I can make the agcl?
If possible, than only the gold is left.

[geubrina]

Arkon, maybe after taking out the Copper by Sulphate acid, I should decant and wash the remain until clean. Then I should put the HNO3, you know to dissolve any metal but the noble one.

Then decant the solution again and use the AR.

Pls tell me is this theoretically, right?

[Arkcon]

Well done, that was the systematic method that I wanted you to develop:
1). Grind to a powder
2). Magnetic separation
3). Sulfuric acid extraction
4). Nitric acid extraction
5). Aqua regia extraction.

Will you quantitate each fraction chemically, or by AA (flame or ICP)?  Or will you simply dry and mass?  Or reduce the soluble components to free metal.  In that case, typically, cupellation is what's done to ores, why have you excluded this?  Or is that not your ultimate goal?  Like I told you months ago -- http://www.chemicalforums.com/index.php?topic=21751.msg83169#msg83169
people hardly ever do this by wet chemical or metallurgical means, anymore.  Unless they're panning/mining for gold in some Alaskan or Siberian homestead.  But even those places are moving towards cyanidation processes.

*[EDIT]*
my misspelling cupell probably screwed up your Google searches, srry

[geubrina]

Well done, that was the systematic method that I wanted you to develop:
1). Grind to a powder
2). Magnetic separation
3). Sulfuric acid extraction
4). Nitric acid extraction
5). Aqua regia extraction.

Will you quantitate each fraction chemically, or by AA (flame or ICP)?  Or will you simply dry and mass?  Or reduce the soluble components to free metal.  In that case, typically, cupellation is what's done to ores, why have you excluded this?  Or is that not your ultimate goal?  Like I told you months ago -- http://www.chemicalforums.com/index.php?topic=21751.msg83169#msg83169
people hardly ever do this by wet chemical or metallurgical means, anymore.  Unless they're panning/mining for gold in some Alaskan or Siberian homestead.  But even those places are moving towards cyanidation processes.

*[EDIT]*
my misspelling cupell probably screwed up your Google searches, srry

Arkon, what will happen if we switch the no.3 and no.4 step?