Electrolytic copper refining cell

[Shark]

I didn’t sew my slime bags. I hot glued them. I used a backing material for clothes making made of a synthetic material I can’t recall the name of now. I will try to get it out and see if any labels are left with it. The hot glue didn’t seem to be affected by the solution and burned fairly easy during incineration. Once burnt, it did need crushing as it did seem to form small sized beads.

Edit to add…. The material was Dacron I think. Kind of non woven fiber looking material.

 

[Ayham Hafez]

What is the best type for small cell tank type, @4metals mentioned about the best operation temperature is 60 c , PVC maximum temperature is 60 c and PP is 82 c so I think PP is better unless there are other issues with it.

In case I will build 200 Ampere cell that will take about 72 liters of electrolyte with 6 cathodes 10x10 inches, will I need external heater or the temperature will increased to 60 c without external heat? will temperature be increased more than 60 c incase voltage less than 6 v?

Another question, usually there is filter pump in electrolysis tanks that remove solid impurities from the electrolyte continuously ( even if there anode filter bags , we will get some solid impurities in the electrolyte), so is it better to have filter pump in 200 Ampere cell?

Last question, can I use stainless steel screws to hook the anodes instead of titanium hooks or screws? Here I wonder how the 316 stainless steel cathode will not be dissolved in the electrolyte? I have a bad experience before with stainless steel and sulphuric acid, 316 stainless steel pot dissolved in sulphuric acid very easily, so how the sulphuric acid of the electrolyte will not dissolve the cathodes?

 

[4metals]

One popular option is koroseal lined steel tanks. There are also many companies that make flexible liners for tanks.

 

[Ayham Hafez]

One popular option is koroseal lined steel tanks. There are also many companies that make flexible liners for tanks.

Trying to find in local market.
Will I need external heater and filter pump? And how 316 stainless steel not dissolved in sulphuric acid?

 

[Martijn]

Trying to find in local market.
Will I need external heater and filter pump? And how 316 stainless steel not dissolved in sulphuric acid?

The current running through the cell will heat it up, and i have noticed that over 40 C, it starts attacking copper and the stainless steel watch bands.. not sure which type of stainless that is, but keeping the cell cool by limiting the current is all you need imo.

 

[Ayham Hafez]

The current running through the cell will heat it up, and i have noticed that over 40 C, it starts attacking copper and the stainless steel watch bands.. not sure which type of stainless that is, but keeping the cell cool by limiting the current is all you need imo.

What will happen when we reduce the current less than 25 Ampere per sq. ft to reduce the temperature?

 

[Ayham Hafez]

Sodium chloride (NaCl) is used in electrorefining as an electrolyte additive for refinement of copper grains and reduction of cathode impurities such as Ag and Sb. This is done by precipitating them out of solution as metallic chloride crystals.

(Google search)

I wonder if gold could oxidized during electrolysis processing so it will react with chloride from NaCl?

When silver react with NaCl, does reaction will be very quick so we will collect the Silver chloride from the anode filter bags? If yes, have we incinerate the filter bags before treating with nitric acid? Is incineration convert silver chloride to silver oxide? If not have we melt the filter bags with mud and flux to make sure we got all silver?


My last question, if we use voltage 4 v for example on 4 cathodes cell, the connection is in parallel, if we measure the voltage between each anode and cathode we will get less than 1 v (after adjusting the amps), so why we don't get 4 v between each anode and cathode according to physics ?

 

[Yggdrasil]

Sodium chloride (NaCl) is used in electrorefining as an electrolyte additive for refinement of copper grains and reduction of cathode impurities such as Ag and Sb. This is done by precipitating them out of solution as metallic chloride crystals.

(Google search)

I wonder if gold could oxidized during electrolysis processing so it will react with chloride from NaCl?

When silver react with NaCl, does reaction will be very quick so we will collect the Silver chloride from the anode filter bags? If yes, have we incinerate the filter bags before treating with nitric acid? Is incineration convert silver chloride to silver oxide? If not have we melt the filter bags with mud and flux to make sure we got all silver?


My last question, if we use voltage 4 v for example on 4 cathodes cell, the connection is in parallel, if we measure the voltage between each anode and cathode we will get less than 1 v (after adjusting the amps), so why we don't get 4 v between each anode and cathode according to physics ?

If you use strong HCl and an electrolytic cell to break the Cl- free you can mange to dissolve Gold, maybe.

The Chloride will react as soon as Silver Ions are present and it will then drop as Silver Chloride in the Bag.
You do not process Silver Chloride with Nitric, so why do you want to burn the bag?
No incineration do not convert to Silver Oxide.
You either process with Lye/Sugar or Zinc/Aluminum and acid.
Or smelt with (Sodium Carbonate?)

If you have 4V in parallel you have 4V over all cells.
If you have 4V in series you have 1V over each cells, kind of.
If you send 4A into a parallel circuit you will have I₁+ I₂ + I₃ +I₄ = 4A
If you send 4A into a circuit in series you will have 4A in each part.

 

[Ayham Hafez]

If you use strong HCl and an electrolytic cell to break the Cl- free you can mange to dissolve Gold, maybe.

The Chloride will react as soon as Silver Ions are present and it will then drop as Silver Chloride in the Bag.
You do not process Silver Chloride with Nitric, so why do you want to burn the bag?
No incineration do not convert to Silver Oxide.
You either process with Lye/Sugar or Zinc/Aluminum and acid.
Or smelt with (Sodium Carbonate?)

If you have 4V in parallel you have 4V over all cells.
If you have 4V in series you have 1V over each cells, kind of.
If you send 4A into a parallel circuit you will have I₁+ I₂ + I₃ +I₄ = 4A
If you send 4A into a circuit in series you will have 4A in each part.

So with copper sulphate cell and E-waste anode definitely we will get silver chloride in the filter bags in precents of NaCl as an additive, so what is the best practice to process the filter bags from the copper refining cell?


Your physics formulas are theorly correct, but with experiment its not, with parallel connection we get different voltage in each cell, also I have another example, my workshop is next to the public electricity transformer, I got approximately 240 v on each electricity line (about 420 v on 3 phases), so I use an indoor transformer to get 220/380 v to save my electric tools, but my far neighbors which connected to the same transformer they don't have an issue cause they get approximately 220 v, when I talked to the electricity company regard this issue they apologized and advised me to use indoor transformer they said we can't reduce it cause far neighbors will get less Voltage that can't be converted to higher Voltage.

Voltage is dropped depends on many things like wire length/quality and temperature, but how voltage is dropped like my example in the copper refining cell? And how we can manage it, silver need 0.7 v to be in sulphuric solution and copper needs 0.35 v, so voltage in cells should be between 0.35 and 0.7, how we can control the voltage between cells? Am not talking about the DC voltage, talking if we use multimeter between each anode and cathode we got different voltage read.

 

[Yggdrasil]

So with copper sulphate cell and E-waste anode definitely we will get silver chloride in the filter bags in precents of NaCl as an additive, so what is the best practice to process the filter bags from the copper refining cell?


Your physics formulas are theorly correct, but with experiment its not, with parallel connection we get different voltage in each cell, also I have another example, my workshop is next to the public electricity transformer, I got approximately 240 v on each electricity line (about 420 v on 3 phases), so I use an indoor transformer to get 220/380 v to save my electric tools, but my far neighbors which connected to the same transformer they don't have an issue cause they get approximately 220 v, when I talked to the electricity company regard this issue they apologized and advised me to use indoor transformer they said we can't reduce it cause far neighbors will get less Voltage that can't be converted to higher Voltage.

Voltage is dropped depends on many things like wire length/quality and temperature, but how voltage is dropped like my example in the copper refining cell? And how we can manage it, silver need 0.7 v to be in sulphuric solution and copper needs 0.35 v, so voltage in cells should be between 0.35 and 0.7, how we can control the voltage between cells? Am not talking about the DC voltage, talking if we use multimeter between each anode and cathode we got different voltage read.

It is simplified, as resistance is a major factor and in parallel that can amount to a bit.
But it was an attempt to get you on the correct track.
For the cell slime we refine as other Silver scrap.
But why use salt in the first place?
Are you running a Silver cell or a copper Cell?
Everything is much easier if you do not introduce Chlorides into your Cell.
Dissolve what dissolves and then process the Chlorides as you usually do.
Combine into new anode and start over.

 

[Ayham Hafez]

It is simplified, as resistance is a major factor and in parallel that can amount to a bit.
But it was an attempt to get you on the correct track.
For the cell slime we refine as other Silver scrap.
But why use salt in the first place?
Are you running a Silver cell or a copper Cell?
Everything is much easier if you do not introduce Chlorides into your Cell.
Dissolve what dissolves and then process the Chlorides as you usually do.
Combine into new anode and start over.

Am talking about copper sulphate refining cell, without NaCl, some silver from the anodes will be dissolved then make a gray layer on the copper cathode ( also palladium with high voltage do the same) so we have to use small amount of NaCl as 4metals advised at the beginning of the thread.

The anode slime will contains some silver chlorides, also some H2So4, so if we don't incinerate it, when we use nitric we will get silver sulphide, so after nitric parting we will get gold mixed with silver chlorides and silver sulphide in addition to PGM's if exist. If we incinerate we will get rid of sulphuric acid so we will only get silver chloride, but if we melt with soda ash we will solve all issues, am just thinking loudly to get an advice.

 

[adam mizer]

In parallel if using 4v there is 4 volt in every circuit.
If not measuring 4 volt there is incorrect connection between surfaces.
Am thinking you are using hanging anode/cathode on 4 volt buss.
If not 4 volt the hangers have dirty resistive connections, needs to be cleaned off.

 

[BGDOCK]

just throwing this out there when measuring voltage it’s the potential difference between L1 and L2 , etc
You’re measuring your positive anode and three negative cathodes right ? So there could be be a few reasons your not getting exactly one V between you cathode and anode
Solution is not uniform
Cathode deposits ( is silver cementing out on the plates and are they uniform in thickness usually the closest to the anode is thicker )
Are the cathode wires the same gauge and length
Connections
Did you twist your meter points or just attach to the cathodes
Is there corrosion at the attachments of the cathode and anodes

Would you mind sending pics , always looking to improve my designs

Thanks
Jeff

 

[Ayham Hafez]

My cell should have 7 anodes and 6 cathodes, I just did a test with 4 cathodes and 5 small copper pipes as anodes (to test the DC of 200 amps), but noticed that voltage is different between each anode and cathode, I used copper wires between the DC and copper bars (anodes and cathodes holders) I didn't measure the resistance between bars and anodes or cathodes , will prepare another test to see if there are resistance in some points.

 

[Yggdrasil]

My cell should have 7 anodes and 6 cathodes, I just did a test with 4 cathodes and 5 small copper pipes as anodes (to test the DC of 200 amps), but noticed that voltage is different between each anode and cathode, I used copper wires between the DC and copper bars (anodes and cathodes holders) I didn't measure the resistance between bars and anodes or cathodes , will prepare another test to see if there are resistance in some points.

To have the exact same voltage you need:
Exact same area, distance, shape, electrolyte saturation and so on.
It will never be the same, and will never be constant.
It will be a living system changing as the conditions change.

Do you have a sketch?

 

[Ayham Hafez]

To have the exact same voltage you need:
Exact same area, distance, shape, electrolyte saturation and so on.
It will never be the same, and will never be constant.
It will be a living system changing as the conditions change.

Do you have a sketch?

I didn't make a sketch, I just building it using parameters mentioned in this thread, now am stuck with copper titration, the system will take about 70 liters of electrolyte in the plastic container and about 30 liters into the filter container (I will use a pump to cool down the electrolyte) , so electrolyte is about 100 liters, next week I will start to train myself on copper titration so I can prepare my electrolyte well, also trying to find the best way for sulphuric acid measuring, should I measure it using titration each time or by only adjusting the amps...

Will finish my experiments and post final results

 

[Yggdrasil]

I didn't make a sketch, I just building it using parameters mentioned in this thread, now am stuck with copper titration, the system will take about 70 liters of electrolyte in the plastic container and about 30 liters into the filter container (I will use a pump to cool down the electrolyte) , so electrolyte is about 100 liters, next week I will start to train myself on copper titration so I can prepare my electrolyte well, also trying to find the best way for sulphuric acid measuring, should I measure it using titration each time or by only adjusting the amps...

Will finish my experiments and post final results

I just have problems picturing a paralell system with odd numbers of electrodes.

 

[Shark]

I just have problems picturing a paralell system with odd numbers of electrodes.

Most copper cells will have an odd number. If you use 5 anodes you need 4 cathodes in order to have an anode/cathode on each side. While the cell in the link uses several smaller pieces I still considered them as one. Making a cell that is a 3-2 anode cathode setup.

https://goldrefiningforum.com/threads/electrolytic-copper-refining-cell.24397/post-274435

 

[Yggdrasil]

Most copper cells will have an odd number. If you use 5 anodes you need 4 cathodes in order to have an anode/cathode on each side. While the cell in the link uses several smaller pieces I still considered them as one. Making a cell that is a 3-2 anode cathode setup.

https://goldrefiningforum.com/threads/electrolytic-copper-refining-cell.24397/post-274435

I see, I had it pictured totally different in my head

 

[goldshark]

So with copper sulphate cell and E-waste anode definitely we will get silver chloride in the filter bags in precents of NaCl as an additive, so what is the best practice to process the filter bags from the copper refining cell?


Your physics formulas are theorly correct, but with experiment its not, with parallel connection we get different voltage in each cell, also I have another example, my workshop is next to the public electricity transformer, I got approximately 240 v on each electricity line (about 420 v on 3 phases), so I use an indoor transformer to get 220/380 v to save my electric tools, but my far neighbors which connected to the same transformer they don't have an issue cause they get approximately 220 v, when I talked to the electricity company regard this issue they apologized and advised me to use indoor transformer they said we can't reduce it cause far neighbors will get less Voltage that can't be converted to higher Voltage.

Voltage is dropped depends on many things like wire length/quality and temperature, but how voltage is dropped like my example in the copper refining cell? And how we can manage it, silver need 0.7 v to be in sulphuric solution and copper needs 0.35 v, so voltage in cells should be between 0.35 and 0.7, how we can control the voltage between cells? Am not talking about the DC voltage, talking if we use multimeter between each anode and cathode we got different voltage read.

Double check to make sure your multi meter is set for DC Voltage, not AC.