dropping copper from solution

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kjavanb123

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All,

I have finally produced a blue solution from leaching the copper ores with diluted acid. I use iron scraps to collect the copper, however it takes a long time to completely drop the copper using this methods. Since I am on small-scale yet, can I use zinc powder to drop the copper quickly? after adding soda ash to the solution to make it pH higher?

Thanks
Kev
 
Thanks man, any range of pH? Obviously the solution itself must have a pH in ranges of 2-3, since it is leached with acid. So I add soda ash till the solution turns clear in color?
 
kjavanb123 said:
Thanks man, any range of pH? Obviously the solution itself must have a pH in ranges of 2-3, since it is leached with acid. So I add soda ash till the solution turns clear in color?

I do not know what the PH is when it turns clear. But yes soda ash is what I use.
 
I have tried selective metal precipitation by using Ph, from my veiw it is almost impossible, but they say it can be done? problem is metal salts seem to over lap when and what Ph they will crystalize out of solution, many factors also come into play like temperature and concentration and types of metals in solution, getting Ph in just the right spot is also very difficult.
it is easy raising Ph to around 9 works good for precipitating most metals out all at once.

For me it is much easier using the solubility tables, and using which metal will dissolve or replace the other to get the metals seperated.
 
I added soda ash to the copper sulfate solution i produced by dropping a copper piece into nitric acid but the color has changed very slightly, there are some salt at the bottom of beaker but no signs of copper, solution still is blue.

In recovering part, is there anything that works faster than iron scrap to drop copper sulfate from the solution?

Thanks
Kev
 
kjavanb123 said:
In recovering part, is there anything that works faster than iron scrap to drop copper sulfate from the solution?

Electricity will remove copper quickly from copper sulfate solutions as long as they are not too diluted.

Steve
 
Agitate (aerate) the solution to move it around and the iron method will work faster, also add a small amount of sodium thiosulfate to the solution and the copper will not cling to the iron as much.
 
Dealing with the wastes, is it better to store and save them while you let them build up.

I mean if someone is planning to do this for a while the waste pile will grow in weight.

Can these mineral chlorides (edit: hydroxides) be safely stored indefinately in plastic containers like that of a milk jug?
I have only been dealing with mostly copper/nickel/gold plate items.
Thinking the copper is green and the nickel is blue.

Here I have seperated the blue and green and also have one container accumulating both.
Trying to decide whether seperating them or storing them together as both is a wise decision.
Trying to get some feedback from you guys.

Ph seems to be for both 7-8 is good then 9 allows the blue/nickel back to liquid, remove green copper, then lower ph (7-8) to drop nickel.
If both were removed and stored they could be dealt with after many gallons of material have accumulated.
 

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Adam,

At the pH you are at, the chlorides are long gone and you are looking at metal hydroxides. The clear water on top is probably very salty if you raised the pH with sodium hydroxide.

In a commercial treatment the pH is raised to 9.5 with either caustic or mag ox and the hydroxides are separated with a filter press. Depending on what else was in solution the solution remaining can be lowered to a pH of 7 and discharged. Commercial testing to local discharge parameters is required.
 
4metals said:
Adam,

At the pH you are at, the chlorides are long gone and you are looking at metal hydroxides. The clear water on top is probably very salty if you raised the pH with sodium hydroxide.

In a commercial treatment the pH is raised to 9.5 with either caustic or mag ox and the hydroxides are separated with a filter press. Depending on what else was in solution the solution remaining can be lowered to a pH of 7 and discharged. Commercial testing to local discharge parameters is required.

Okay what do you know, I'm learning. So I'm looking at metal hydroxides now.
Thanks for that information.
An education is what I'm lacking while I learn from gaining experience its a slow process but a very interesting one.

Wanted to add, while I was trying to make seperation of metal hydroxide colors, noticed a small amount of orange-brown on the bottom as well as some small chunky black.
I'm more interested right now in the orange-brown wondering what this little bit would be.
I saved the odd mixture in a seperate container for a later time.
Guess I just don't want to toss anything as I know there will be a build up in weight for each metal.
 
Here's something interesting to me.

My fresh mix seperation was basically blue and green in the buckets in the picture above posted Jan 22nd freshly seperated.
Took a look at it today as I processed some more waste.
The green turned rich deep gray. :shock: Guessing (again) think its the nickel.
The blue turned green. What gives! :shock: Think this is my copper.

Wow a complete reversal and color change after sitting.???
 
What about aluminum? If I drop copper with aluminum from copper chloride is there a contamination of aluminum in my copper precipitate or is it mostly in solution and copper on the bottom?
 
are you tryign to get pure Cu out of this? Wouldnt dropping the Cu with iron leave you with Cu(II)Cl?

Would using electricty to drop the copper leave you with pure Cu?
 
loitz2313 said:
What about aluminum? If I drop copper with aluminum from copper chloride is there a contamination of aluminum in my copper precipitate or is it mostly in solution and copper on the bottom?
There would be a small amount of contamination from the aluminum. But aluminum will drop copper pretty fast. I use aluminum to drop copper out of copper chloride solution. Don't use aluminum foil it will cause alot of contamination. Someone correct me if I am wrong but I believe this to be true.
 
Also make sure you are in a well ventilated area the aluminum will produce hydrogen gas. A small spark can really make a loud bang.
(edited for a spelling error.)
 
Thanx man I just wanted to make sure. I have been avoiding my wastes and now it's time to start working on them. but today I did a small test and "oops" I used foil but it was only a small test hence my post thanx you've helped alot.
 
Hi just a quick thought, when my electrowinning cell is exhuasted, i recycle the PMG side for further use after filtering. The copper side contains copper crumbs, impurities, and copper sulphate. I make my own soda ash by hot wash and filter of our wood burner ash. This is more than enough to ppt any copper and anything else as either the carbonate or oxide. The ppt is very gluggy, though will filter over night. I use a inverted plastic bottle (bigger for big lots) with it's bottom cut off, i drill a 8mm hole in the lid, oh, it's easyer to do this with the lid still on :lol: . Jamming cotton wool into the inside of the lid, um lid is on, then poor in enough sand to cover the cotton wool by about an inch. Now for the clincher, jamb in a nylon stocking on top of the sand. This dramatically enhances the filtering of difficult ppt's. Pour in the copper glug and it will filter to a mud. If washng is your thing, then after the first filtration is complete pour in, just boiled, hot water. I dry the mud, and melt to produce high copper alloy, sold as brass.

I can take pick of both the filter and mud and dried product if anyone is interested, sorry no pics of the brass, that's coming.

Cheers
 
kjavanb123 said:
All,

I have finally produced a blue solution from leaching the copper ores with diluted acid. I use iron scraps to collect the copper, however it takes a long time to completely drop the copper using this methods. Since I am on small-scale yet, can I use zinc powder to drop the copper quickly? after adding soda ash to the solution to make it pH higher?

Thanks
Kev


If you want to cement Cu with iron scraps the best way is to take Cu sheet, using copper wire connect it with iron scrap and submerge the connected bits in the liquid you want to drop copper from. Make sure the wire link between both pieces of metal is above the liquid level. If surface area of copper sheet is bigger (the bigger difference the better) than surface area of iron scrap then most of the Cu will cement on top of the copper sheet as a layer of solid metal. By playing around with surface areas and temperature (pH doesn't play significant role in my experience as long as the solution is acidic) you could get all Cu out as a plated deposit and you could eliminate the need of filtration.


What you are doing is creating a battery. Because of standard electrode potentials copper is more likely to deposit on copper then iron. When copper atom deposits the Cu2+ ion needs 2 electrons. At the same time Fe atoms want to get rid of electrons in order to forms positive ions (Fe2+ and/or Fe3+). The wire link between copper sheet and iron scrap provides easy way for electrons to travel from one end to the other, thus speeding up significantly the whole process.
At the same time, because Cu deposits on different electrode than Fe ions are taken from the Cu deposits do not block electrolyte from beeing in touch with Fe scraps what speeds up the process even further.

The smaller distance between copper sheet and iron scrap the better - smaller travelling distance for electrons.
The thicker the wire link between cooper sheet and iron scraps the better - thicker wire means less resistance.
The best wire link is copper one - lowest resistance.

Have fun :mrgreen:
 
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