Recovery of copper from ore

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PCZim

Member
Joined
Jan 1, 2015
Messages
14
Hi guys

I am looking for a relatively inexpensive way of recovering copper from ore.

On one of my mines I have encountered a very copper rich belt at a depth of 18 meters. Good gold content and hardly copper from 5- 15 Metre then the gold reef merged with a large copper belt. Assays say 4 percent copper. The gold content at milling varies between 6 to 10 g per ton even after meeting the copper belt. This makes my sands virtually useless for leaching, I do however have a lot of copper I am throwing away; 40kg per ton.

Right now I’m mining around 5 tons a day but if I can find a cheap bit effective way of extracting the copper, I would like to venture into the unknown and process copper as opposed to process my sands for gold. If I can find a way I will move some machinery on and increase my production to 20 tons a day.

Most of the research I have done has pointed me at large scale copper mining information. I’m specifically looking at very small scale solutions.

Many thanks in advance
 
Some question I have is in what form is the copper? Metallic, malachite (copper carbonate), copper silicate, copper sulphide? What is the host rock it appears in?

Copper flotation (sulfide ore) could be done in quite a small setup. I think there were some posts in the beginning of the forum where a guy showed how to put together the equipment.

I don't have any personal experience in small scale copper mining but if you answer the questions I asked above then there is a bigger chance that someone with the knowledge will answer.

Göran
 
Hi Goran

Thank you for the reply I believe it is copper oxide although I stand to be corrected. Here is a picture of one of the pieces I picked out. I will need to take a picture of the ore pile.
9E205AA0-D591-4B59-9AA0-12BFC22649B7.jpeg
 
This is asking for classical method: 1.grinding 2.H2SO4 leaching (in a "pachuka" with air bubbling) 3. Scrap iron precipitation
 
The Leaching of Dolomitic-Copper Ore Using Sulphuric
PDF
https://www.google.com/url?sa=t&source=web&rct=j&url=https://pdfs.semanticscholar.org/e485/814a921e614321065b67e9b88ac7f2764676.pdf&ved=2ahUKEwjulpWOuprdAhWE7oMKHXCYAv4QFjAMegQICBAB&usg=AOvVaw3lz0dYMido1sew7Qr9uy__
 
Thank you all. I have spare leach tanks I can use, now have to learn about precipitation. I know a bit about electrowinning as I elute in gold mining. Is there a basic guide anyone can recommend to precipitate using iron?
 
PCZim said:
Is there a basic guide anyone can recommend to precipitate using iron?
It's a very simple process. The pregnant solution is put into a container of some type with a bunch of scrap iron. The iron will dissolve into the solution, and as it does, it will give up electrons to the dissolved copper, reducing it to metallic copper. It's known as a replacement reaction. You want good circulation of the solution over the iron. Air bubblers work well. When the replacement is complete, the excess iron can be removed from the cemented copper with a magnet.

Decant or siphon the solution off the copper sediment, then wash the copper.

At that point, you have a solution of ferrous sulfate. The water can be evaporated, and the resulting crystals can be used to precipitate gold, or sold.

Dave
 
FrugalRefiner said:
PCZim said:
Is there a basic guide anyone can recommend to precipitate using iron?
It's a very simple process. The pregnant solution is put into a container of some type with a bunch of scrap iron. The iron will dissolve into the solution, and as it does, it will give up electrons to the dissolved copper, reducing it to metallic copper. It's known as a replacement reaction. You want good circulation of the solution over the iron. Air bubblers work well. When the replacement is complete, the excess iron can be removed from the cemented copper with a magnet.

Decant or siphon the solution off the copper sediment, then wash the copper.

At that point, you have a solution of ferrous sulfate. The water can be evaporated, and the resulting crystals can be used to precipitate gold, or sold.

Dave

Dave, thank you. I’m going to do a small test of this week with around 100kg of ground ore. How would I then purify this to pure copper? Unlike gold you would not be able to use nitric or sulphuric. What steps would you use to purify to turn it into a sellable product?

Sorry for the questions, I have a lot to learn.
 
PCZim said:
Dave, thank you. I’m going to do a small test of this week with around 100kg of ground ore. How would I then purify this to pure copper? Unlike gold you would not be able to use nitric or sulphuric. What steps would you use to purify to turn it into a sellable product?
You definitely work on a different scale than many here. :lol: If I were going to run a test, I might start with 1kg. Based on my results, I would start to scale up.

Copper is typically purified with an electrolytic copper cell. While commercial refining of copper isn't really the focus here, you will find some discussion. A few members have built some small cells. For more extensive information, the subject has been well covered in many of the old refining books available through Google books.

Dave
 
Thanks Dave. I have tons of milled ore from this mine sitting discarded as I cannot leach them for gold so may as well test a bigger amount plus I have quite a few blue plastic drums around that will work fine for that amount. I have a friend who is a mining engineer, he may be able to build a cell for me. In the interim let me try precipitation :D
 
Building a small cell is very easy and using one you can recover any values from the slimes which in your circumstance is a real bonus as any extra values you can recover will help finance your operation without you needing to find the money from your own or another’s pocket.
Good luck and keep us informed on your progress as we all love a success story especially from the mining membership as it’s so rare.
 
Thanks guys. Well I did a couple of elutions today and seems some of the copper infested sand got mixed with our regular sand for leaching. Check this copper plating. Very less gold for me today unfortunately, think there my be lock up in my carbons so will acid wash and elute again.

This is not what you want to see as a gold miner!
EBE98D7D-B743-40DA-BC66-DF3270D6C96D.jpegE1ADFA5B-4ADB-4834-9887-2A5B0EE92A39.jpeg
 
I think one of the experts on mining here on the forum is Deano, http://goldrefiningforum.com/phpBB3/search.php?author_id=40539&sr=posts

Maybe he can give you some advice. He seems happy to share his knowledge with anyone who would listen.
You could send a pm and ask him if he has something to add to this thread.

Göran
 
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