What is the method for parting palladium from copper?
- Thread starter Ragnor
- Start date
Help Support Gold Refining Forum:
Electrolysis of the copper and then refining the anode slime.
Göran
Göran
Also, depending on how much pd to cu you could just dissolve it all in nitric and cement to copper.
Or, if you were handy, it may be possible by not using too much nitric, to stop at a point were the values cement back out on remaining copper.
Or, if you were handy, it may be possible by not using too much nitric, to stop at a point were the values cement back out on remaining copper.
So If I had a sodium sulfate solution and a copper cathode and used the nugget as an anode. Would that theoretically pull the copper into solution and onto the cathode and leaving my values as a sludge? does that cut it for a possible method?
My thinking on the sodium sulfate is that I have it handy and it will create an acidic solution. When voltage is applied I should get a copper sulfate solution formed in the container. This seams to be a method discussed on the internet for copper refining.
I have another question concerning safety.
Is there any potential for evolving any deadly or highly toxic gasses with this method? I am seeing a white mist puff off of the top of the container as bubbles burst on top of the solution.
I am running an exhaust fan and have the door open in the room for a good cross flow, but I am moderately concerned as I do not know they exact composition of the nugget and I do not know what gasses might be able to be evolved by this process.
I have another question concerning safety.
Is there any potential for evolving any deadly or highly toxic gasses with this method? I am seeing a white mist puff off of the top of the container as bubbles burst on top of the solution.
I am running an exhaust fan and have the door open in the room for a good cross flow, but I am moderately concerned as I do not know they exact composition of the nugget and I do not know what gasses might be able to be evolved by this process.
I am thinking that the white mist is the mist created when the numerous bubbles are bursting at the surface of the solution from the electrolysis. With respect to your question about the off-gassing, I think it is prudent to be concerned with safety. When you say that you run a fan and leave the door open, I am hoping that the "room" is not inside your home. Electrolysis can produce various gasses depending on the electrolyte, cathode composition, anode composition and other factors.
If you are doing it inside your home, is there anyway to setup the cell outdoors under a covered area or in a detached garage or shed?
If you are doing it inside your home, is there anyway to setup the cell outdoors under a covered area or in a detached garage or shed?
Topher_osAUrus
Well-known member
Ragnor said:
Where? Can you share a link?
As far as your safety question, listen to geedigity, he is a pretty smart guy. Your health isnt worth a few bucks in pure copper.
upcyclist
Well-known member
I thought sodium is more reactive than copper, which means the sodium would stay in solution while the copper stays put?Ragnor said:
How big is your anode?
How big is your cathode?
How many amps are you running in the cell?
What power supply are you using?
How big is your cell?
Yes there is potential for some gasses being produced that are dangerous. This should have been your first consideration before running a cell. While they sound simple, they can be very far from it.
I am using a a bench power supply. Voltage set from 7-10v at .1-.2 amps. Cathode is a 1.25" loop of 10ga. copper wire. Anode is a .75" diameter .25" thick slab of copper/PGE/silver/? piece of slag from a hydrothermal vent.
So, the using the NASO4 adding sodium sulfate to water yields sulfuric acid, correct? sulfuric acid and copper makes copper sulfate. Now the part I don't know about is the effect of the Na on the solution. My assumption was that it would just act as a charge carrier. If I am mistaken please correct me.
http://science.jrank.org/pages/2353/Electrolysis-Refining-copper.html
https://pubchem.ncbi.nlm.nih.gov/compound/sodium_sulfate#section=Top
http://electro-lysis.blogspot.com/2011/01/selective-discharge.html
I do not know the original link URL, I didn't note it at the time and do not recall my exact search terms.
The fan I run is a 220V squirrel cage from a hvac system mounted through hole in the wall. Not just a house fan in a window. But yes I do live and work in the same space most often. Obviously I do not use strong acids in the house or anything like that. My first thinking was along the lines of having run large HHO cells and numerous ozone generating HV experiments without any trouble. But having become aware of things like arsine I have gotten allot more nervous about working with ores in the house anymore. If it's prudent I will most certainly run some power to an outbuilding and set up a more proper hvac system (fume hood) out there.
So, the using the NASO4 adding sodium sulfate to water yields sulfuric acid, correct? sulfuric acid and copper makes copper sulfate. Now the part I don't know about is the effect of the Na on the solution. My assumption was that it would just act as a charge carrier. If I am mistaken please correct me.
http://science.jrank.org/pages/2353/Electrolysis-Refining-copper.html
https://pubchem.ncbi.nlm.nih.gov/compound/sodium_sulfate#section=Top
http://electro-lysis.blogspot.com/2011/01/selective-discharge.html
I do not know the original link URL, I didn't note it at the time and do not recall my exact search terms.
The fan I run is a 220V squirrel cage from a hvac system mounted through hole in the wall. Not just a house fan in a window. But yes I do live and work in the same space most often. Obviously I do not use strong acids in the house or anything like that. My first thinking was along the lines of having run large HHO cells and numerous ozone generating HV experiments without any trouble. But having become aware of things like arsine I have gotten allot more nervous about working with ores in the house anymore. If it's prudent I will most certainly run some power to an outbuilding and set up a more proper hvac system (fume hood) out there.
Your running way to much voltage, and the amperage is still fairly high as well. You want to calculate the amperage needed for your cell based on the size of your cathode. To much current and you will get a powdery deposit that may or may not even stick to your cathode. When this happens part of your PGM's can carry over as well causing you losses of your values. Take a look at 4metals post on copper cells, he has explained it very well. Those first two pages he goes into some great detail on the how and why of the workings for these cells.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=86&t=24397
Sodium in a cell has the potential to create chlorine gas and maybe a few others. Depending on the makeup of the electrolyte the gas produced can vary from allergic reaction to very deadly. Be careful about confining or breathing these gases.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=86&t=24397
Sodium in a cell has the potential to create chlorine gas and maybe a few others. Depending on the makeup of the electrolyte the gas produced can vary from allergic reaction to very deadly. Be careful about confining or breathing these gases.
Topher_osAUrus
Well-known member
Ragnor said:
Copper doesnt really dissolve easily in sulfuric acid (except for hot concentrated sulfuric, or sulfuric and an oxidizer)
Thats why we use the copper mesh anode basket in the sulfuric stripper and dilute sulfuric as a pickle to clean copper oxide off of copper metal.
Copper sulfate can be made, however, by adding sulfuric acid to copper chloride and evaporating it down, turning the chlorides to sulfates.
Same goes for copper nitrate, which has the added benefit of releasing NO2, which can be captured to make nitric acid.
Search for butcher's brilliant "two birds one stone" thread
goldandsilver123
Well-known member
- Joined
- Aug 11, 2015
- Messages
- 205
Just Sodium Sulfate (Na2SO4) and water for your electrolyte is going to make a mess.
Note that a solution of Na2SO4 have the pH 7.
At the very start of the electrolysis hydrogen will be produced at the cathode but then the hydrogen concentration at the cathode will be too low (raise the pH) and other reactions can take place, like with the sulfate anion, even with the eletrostatic repulsion of the anion with the cathode.
The pH of this cell will increase and with copper dissolving at the anode you will start to make copper hydroxides, most probably the electrolysis will stop due to formation of copper hydroxides at the surface of the anode.
If Salt (NaCl) or other source of chlorine wasn't added there's no chance of producing chlorine gas.
If your salt is NaHSO4 then it's another story.
It's far easier to make a copper sulfate solution with sulfuric acid to lower pH and increase conductivity, copper deposition will start right way. Better formulations can be found at 4metals post.
Note that a solution of Na2SO4 have the pH 7.
At the very start of the electrolysis hydrogen will be produced at the cathode but then the hydrogen concentration at the cathode will be too low (raise the pH) and other reactions can take place, like with the sulfate anion, even with the eletrostatic repulsion of the anion with the cathode.
The pH of this cell will increase and with copper dissolving at the anode you will start to make copper hydroxides, most probably the electrolysis will stop due to formation of copper hydroxides at the surface of the anode.
If Salt (NaCl) or other source of chlorine wasn't added there's no chance of producing chlorine gas.
If your salt is NaHSO4 then it's another story.
It's far easier to make a copper sulfate solution with sulfuric acid to lower pH and increase conductivity, copper deposition will start right way. Better formulations can be found at 4metals post.
Cerber, welcome to the forum.
Please make your posts in English. Most of our members speak English, but very few speak Russian.
Dave
Please make your posts in English. Most of our members speak English, but very few speak Russian.
Dave
Eftersom vissa personer försöker att uppfinna ett bättre hjul... utan att först ha lärt sig hur ett hjul fungerar.Cerber said:
:mrgreen:
Göran
A long story about parting Cu from Pd.
About 45 years ago, we had 50,000 pounds of telephone relay scrap, including the weight of the steel shelving, with pure Pd contact points mounted to copper alloy relay blades. When we cut the points off the blades, they were trimmed as short as possible. I spent several days experimenting with methods to dissolve the copper base without even slightly etching the Pd. I wanted to keep the Pd in its original form, as is, since it was pure to start with and my policy has always been: if the metal is pure to start with, don't screw with it. I tried many things that didn't work. The problem was that most things that dissolved copper also dissolved Pd. At that time, Pd was worth about $80/tr.oz. and the Pd value of the 50K# was about $50K - about $1 per pound. It took 2 people a month to process it. Today it would be worth about $680K.
I ended up using a solution of sulfuric acid and chromic acid. It was the first and last time I used that mixture. It worked very fast, dissolved 100% of the copper base and didn't touch the Pd. I don't remember whether we heated it, or not (we probably did - say, about 140F), but I do seem to remember that I used 2900ml of conc. H2SO4 and 4 pounds of chromic acid. Something else I don't remember is how much it was diluted with water. However, I would guess that I also used 2900ml of water. The big problem is that chromic acid is hexavalent chromium, which is a big no-no nowadays. Instead of chromic acid, potassium dichromate, which is maybe less hazardous than chromic acid, although it is also hexavalent, might work. I bought a pound of it on Ebay a few years ago for another project.
After dissolving the Cu, we found that there was still a nickel backing on the Pd points. This was discovered when the guy that was buying the points stuck a magnet in the points to remove a staple. We were quite embarrassed when a big clump of Pd points stuck to the magnet. I ended up using hot conc. HCl to dissolve the nickel, without touching the Pd. Then we sold the point as pure Pd.
Back then, just about every job shop plating facility had huge chromic acid plating baths for plating such things as car bumpers. These same plating shops dumped about everything down the drain, back then. I could tell a lot of horror stories about this (also, see Erin Brockovich). Most all platers today are now using the less hazardous trivalent chrome baths.
I'm not suggesting using the sulfuric/chromic solution on your material (I do think it would work, though), unless you have a way of properly treating the Cr+6 waste, which is not that simple. I'm just relating a story. I will say that this combination was almost a miracle solution, in the way it parted Cu away from the Pd.
About 45 years ago, we had 50,000 pounds of telephone relay scrap, including the weight of the steel shelving, with pure Pd contact points mounted to copper alloy relay blades. When we cut the points off the blades, they were trimmed as short as possible. I spent several days experimenting with methods to dissolve the copper base without even slightly etching the Pd. I wanted to keep the Pd in its original form, as is, since it was pure to start with and my policy has always been: if the metal is pure to start with, don't screw with it. I tried many things that didn't work. The problem was that most things that dissolved copper also dissolved Pd. At that time, Pd was worth about $80/tr.oz. and the Pd value of the 50K# was about $50K - about $1 per pound. It took 2 people a month to process it. Today it would be worth about $680K.
I ended up using a solution of sulfuric acid and chromic acid. It was the first and last time I used that mixture. It worked very fast, dissolved 100% of the copper base and didn't touch the Pd. I don't remember whether we heated it, or not (we probably did - say, about 140F), but I do seem to remember that I used 2900ml of conc. H2SO4 and 4 pounds of chromic acid. Something else I don't remember is how much it was diluted with water. However, I would guess that I also used 2900ml of water. The big problem is that chromic acid is hexavalent chromium, which is a big no-no nowadays. Instead of chromic acid, potassium dichromate, which is maybe less hazardous than chromic acid, although it is also hexavalent, might work. I bought a pound of it on Ebay a few years ago for another project.
After dissolving the Cu, we found that there was still a nickel backing on the Pd points. This was discovered when the guy that was buying the points stuck a magnet in the points to remove a staple. We were quite embarrassed when a big clump of Pd points stuck to the magnet. I ended up using hot conc. HCl to dissolve the nickel, without touching the Pd. Then we sold the point as pure Pd.
Back then, just about every job shop plating facility had huge chromic acid plating baths for plating such things as car bumpers. These same plating shops dumped about everything down the drain, back then. I could tell a lot of horror stories about this (also, see Erin Brockovich). Most all platers today are now using the less hazardous trivalent chrome baths.
I'm not suggesting using the sulfuric/chromic solution on your material (I do think it would work, though), unless you have a way of properly treating the Cr+6 waste, which is not that simple. I'm just relating a story. I will say that this combination was almost a miracle solution, in the way it parted Cu away from the Pd.
chuckgambale
Well-known member
- Joined
- Jul 16, 2014
- Messages
- 72
Wow I am never ever sorry that I read a post by GSP. Your experience is only exceeded by your willingness to share it with us. Thank you sir from me and everyone else lucky enough to benefit from your experience.
