# My first try at refining.



## jimmythehand (May 7, 2013)

Hey guys, I just wanted to say thanks for all the valuable info on this site. It provided me with many hours of entertainment as I slowly learned the process.
Anyway, here are the pics of the source material.
It still needs to dry a little before i can melt it, but was so excited about it I wanted to post what i have so far.


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## squarecoinman (May 8, 2013)

Jimmy looks like nice clean 30 to 40 grams of silver 

well done

squarecoinman ( scm)


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## butcher (May 9, 2013)

Jimmy, the chemistry of metals is fun and very educational, I think you are hooked now with your new hobby, post a picture of the silver after you melt it.


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## jimmythehand (May 9, 2013)

Ill get some pictures of the melt, just waiting for the crucible.
I'm also curious about some other scrap that i have. They are the brazed joints from HVAC industry. The braze will contain 5-15% silver. I'm wondering if there is a cost effective way to recover this, especially since I obtain the metal for free.


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## squarecoinman (May 9, 2013)

Jimmy do you know what other metal is in your scrap ? 

The way to count out if you should do it or not is : Take 3 and a few milliliter of acid ( the acid depends on if there is copper or tin etc ) and see how good they dissolve and if you can get the silver to drop , then you take the weight of the 3 and multiply that until you have a kilo. In a Kilo you will have between 50 and 150 gram silver , then see how much acid you will need to dissolve 950 gram of the other material , and take the cost of the acid of the value of the silver.

with the prices I pay for Acid , it would currently be a loss for me 

I hope you do read Hoke , in the book there are some interesting experiments that can guide you 

regards scm


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## butcher (May 9, 2013)

The silver solder was 5 to 15% silver solder, what you have in your hand is mostly a copper fitting with a little bit of silver solder on it, I would use those when you need a piece of copper to cement values from a solution, or use them as a collector of values in your stock pot, eventually the copper will dissolve away, and you can recover silver later.


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## jimmythehand (May 9, 2013)

I thought about using them to drop the silver out of solutions, but I hace over 200lbs of those fittings and i can easily obtain more. 
It just irks me to sell it as copper scrap when there should be quite a bit of silver in there.
Maby a way to refine the copper and recover the silver as waste?


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## jimmythehand (May 9, 2013)

squarecoinman tho only metals in this would be copper and silver. The brazing rods are typically mostly copper with 5-15% silver and 5-6% Phosphorus.


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## butcher (May 9, 2013)

It seems to me Rusty had a project using those, If my memory is not as bad as I know it is, he was electro-winning the copper.

If I had 200 pounds I would probably try some in the concentrated sulfuric acid stripping cell, and see If I could strip the silver from the copper.


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## bigredlee (Jan 16, 2014)

I know this post is old but I am thinking about doing some of this myself. The only way I can figure it would be worth it is if you get the copper as well. I think of it like this.
At best I can mechanically separate the fittings down to where it is about 5%braze and 95%copper.
This is still #2 copper at any scrap yard and as I am writing this #2 brings about 2.5/pound.
At best the braze is 15%silver..some "cheap brazing rods" are 5% assuming the best case you are looking at 15% of 5% silver or .75%.
There is approx 450 grams/pound or 3.37 grams of silver. Today's spot price of silver is 20.16/31.1g. So there is somewhere around 2.18 at full spot of silver in a pound(best case, could be less than a third of this).

I would be interested in doing this myself if there is a way to capture both, otherwise call all the yards around you and sell the 200 pounds for 500 dollars and have fun.


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## nickvc (Jan 16, 2014)

The only economic way as a stand alone project is a small to medium sized copper cell so long as the scrap yards will take your copper from the cell, that way the silver is basically free. Bear in mind all cells work better with high grade feed stock so if you have 98% Cu then you should be good to go.
Copper cells are one of the oldest and most widely described metal refining processes and details of the whole set up and running of them are easily available.


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## butcher (Jan 16, 2014)

My punch bowl silver/copper recovery cell.
I use a punch bowl for the cell, put the silver soldered copper pieces, copper bars of silver electrical contact points, in an old sock, and stick a longer piece of silver soldered piece of copper pipe down in the sock (in the middle of the smaller copper pieces), this pipe is the anode connection that the sock is tied to with a piece of shoestring, the pipe that sticks out of the sock also sticks up out of the punch bowl, a wood cloths pin or string tied to the anode pipe keep the sock up off the bottom of the cell.

The cathode is very thin copper foil which came from old electrical transformers ground plane winding, it is folded over the punch bowls lip for the cathode connection, and hangs down in the bowl but up off the bottom.

Copper sulfate is the electrolyte, this copper sulfate is a byproduct from making nitric acid previously.

A glass cover (old glass plate out of a microwave turn table) acts as a cover the anode pipe will not let it completely cover the punch bowl when in use, but provides a good cover to keep leaves and bugs out of the electrolyte.

A 12V DC (actually 14.5 V) battery charger is used as a power supply, the positive of this power supply goes to an old truck or cars head light bulb, the other wire lead from the head light bulb is clamped to the anode the copper pipe with the sock full of copper silver soldered joints.

The battery charger negative is hooked to the thin copper foil cathode of the cell.

The car head lamp helps to limit current to the cell, it also protects the power supply if the cell shorts out, it gives a good indication of what is happening in the cell at it light is dependent on the resistance of the cell. A plus is it light up the lab at night.

The copper from the sock plates onto the cathode foil which becomes much thicker, the copper also grows in a form that resembles ocean coral.

Oils from the copper is burned off with a propane torch, and rinsed with water, before it sees the cell.

Silver powder and pieces are retrieved from the sock and the bottom of the cell, are collected for later refining, some pieces of the copper coral which breaks off the main cathode easily are saved for cementing solutions with, the copper coral is washed and saved for future project or to sell as copper.

The electrolyte and copper cathode work well in this cell to separate the silver and copper, this cell is more of a recovery cell, the material from this primary recovery cell (copper coral and the silver chunks and powders could be further refined from this cell in a cleaner cell (refining cells for silver or copper) where the electrolyte is not as contaminated from the things you introduced into this primary recovery cell.


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## bmgold2 (Jan 16, 2014)

Good post Butcher,

Was your "copper coral" solid pieces? Got any pictures?

I have been trying to make some "copper trees" by electrorefining some copper pipe but so far all I get is copper sponge. I have a variable current/voltage power supply rated at only 3 amps that I have been using. My electrolyte was a weak sulfuric acid that has dissolved copper in it. My container is just a small jar and my [stt]cathode[/stt] anode is a piece of copper pipe. My [stt]anode[/stt] cathode was just a piece of 12 gage wire so maybe I need a larger surface area. The voltage I have tried was anywhere from about 0.7 volts and up to around 1.5 volts. The current started out small (10 mV or so) and up to 1 amp. It seemed that the higher I went, the faster it went but the copper didn't stick to the [stt]anode[/stt] cathode at all. 

This is just an experiment and I know it is not worth doing but I would like to make a decorative chunk of copper like I seen at a rock shop many years ago. I figured that, if I could do this, it might be good practice for a small silver cell. I know copper is supposed to be more difficult than silver but it sounds like you got something like what I was looking for. I really liked your sock idea too.

I would like to build a silver cell that could process around an ounce. I don't have enough scrap silver to waste trying to build a large silver cell and don't see any need to build a large cell just to "play around". I assume the silver cell (and the stripping cell) could be scaled down but someone correct me if I'm wrong. I would love to make lots of money at this refining game but honestly my interest (right now) is strictly for my own personal education and enjoyment. Less cost, less chemicals, less waste, and mostly less chance of risking a lot of precious metals. Now, once I have the confidence that I can do it, I'm not against making money but that's not my goal.

bmgold2


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## butcher (Jan 16, 2014)

Here is close to 5 pounds of cathode copper


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## jonn (Jan 16, 2014)

Those are beautiful Butcher. :mrgreen:


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## bigredlee (Jan 17, 2014)

Butcher thank you for the very informative reply. I will save up my brazed fittings and give this a try when I fill a 5 gallon bucket. 

Speaking of brazed pieces I also run into a lot of heat exchangers, which are sheet 316L SS brazed together to provide layers for fluids to flow through. The brazed joints get old and the whole thing ends up getting replaced. These range from 5 to 50 pounds each and most of that is 316L, which is easily sell-able at .80-.95 a pound. But the yards wont take them because of the brazing alloy(I am not 100% sure which alloy it is but the color is identical to AG15-CU84) The economics of this make the 316L much more valuable than the alloy. So does anybody think a cell could be devised to strip the brazing alloy and maybe keep the silver and copper as a bonus?

Lee


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## nickvc (Jan 17, 2014)

Stainless is resistant to nitric whereas copper and silver dissolve easily if that helps.


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## bigredlee (Jan 17, 2014)

Yes that helps alot...

Thank you all


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## butcher (Jan 17, 2014)

You could try one of the stainless steel joints in nitric acid to see if they are silver soldered, using HCl or NaCl to see i you get the white silver chloride from the nitric solution, or try a test with schwerters solution to see i you get the blood red reaction, I cannot see the joints they may be soldered, but I would suspect stainless steel joints to be welded with stainless, simple testing would tell you the answer either way.


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