Reusing old copper chloride solution to attack copper or Iron chloride solution to dissolve copper, this will work for gold or silver, the silver will form chloride so some of the silver makes silver chloride, some of the thicker pieces of silver are left protected by the chloride crust.
With any recovery methods the more of the base metal you can remove mechanically (like cutting the silver contacts off of the large copper bus bar), the less base metal you will have to dissolve.
Collection of some older posts I made on this subject:
Old used Copper II chloride solution (reusing the waste), or making and using the ferric chloride leach...
Ferrous chloride FeCl2 can be made dissolving Iron in HCl and water approximate equal volumes of water and acid, (steel wool or transformer laminates).
Fe (s) + 2HCl (aq) + H2O (l) --> FeCl2 (aq) + H2 (g)
Ferrous chloride FeCl2 with excess HCl will oxidize with air to form Ferric chloride, but the reaction can take a long time.
FeCl2 (aq) + 1/4 O2 (g) + HCl (aq) --> FeCl3 (aq) + 1/2 H2O
Now from the ferrous chloride FeCl2, we can make ferric chloride FeCl3, with about equal volume of 3% Hydrogen peroxide H2O2. Heat is generated in the reaction of oxidation of the iron chloride.
FeCl2 (aq) + H2O2 (aq) + HCl (aq) --> FeCl3 + H2O + H + O
Ferric chloride (FeCl3) can etch copper (Cu) or iron (Fe), oxidizing the copper or iron into solution and reducing the ferric chloride (FeCl3) back to ferrous chloride (FeCl2).
2FeCl3 (aq) + Fe (s) --> 3FeCl2 (aq)
Etching copper a two step process.
FeCl3 (aq) + Cu (s) --> FeCl2 (aq) + CuCl
Then
FeCl3 (aq) + CuCl --> FeCl2 (aq) + CuCl2 (aq)
Now we have discussed the normal leach for copper used to etch copper.
Let add some things to this discussions where we can continue to use this solution.
(This discussion also applies to the old used copper II chloride leach we can no longer use because it has been contaminated with iron or Kovar.)
We can heat this solution (ferrous chloride and cupric chloride (FeCl2 + CuCl2) with more copper, (this copper could be copper we need to dissolve from other metals like silver or gold plating like pins or pieces of copper with silver contact points...), the solution when heated being still acidic eats at the copper with a vengeance, especially as it gets concentrated, heating it to a fairly thick dark brown solution.
FeCl2 + CuCl2 + Cu (s) --> FeCl2 (aq) + 2 CuCl (aq)
Here we have both ferrous chloride and cuprous chloride dissolved in solution.
This leaves us with ferrous chloride and cuprous chloride in solution, If we decant a portion of this solution into a jar and let it cool, Most of the CuCl will settle out as a dark powder (along with any gold flakes, silver chloride, lead chloride if involve...).
Now once cooled and settled we can we can decant the mostly ferrous chloride back to the main solution (we will discuss it more later).
The copper I chloride (cuprous chloride) (CuCl), can be rinsed with Hot boiling water (this will dissolve some salts of the iron and copper chlorides, and lead (this rinse water decanted hot can also be returned to the main solution.
This leaves us with white powders of copper I chloride, silver chloride and gold flakes, now we can save these powders for reuse later.
Or dissolve the CuCl in HCl.
CuCl + HCl --> CuCl2
So now after we let the silver chloride and gold foils settle, we can decant the CuCl2 solution, Which is clean enough to use as a new batch of copper II chloride leach (CuCl2) (miss-named acid peroxide leach, or AP on the forum).
Now back to or FeCl2 ferrous chloride solution if you reread this post from the beginning you can see where the ferrous chloride solution (FeCl2) can be oxidized back to the ferric chloride FeCl3 to leach more copper or iron...
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Now we can get some other iron products, or byproducts, from these iron solutions with the methods above, iron solutions can hydrolyze and with oxygen can form some insoluble iron oxides or hydroxides in solution, or precipitate from solution. Strong heat can accelerate this. One of these can be a red Iron powder (red rouge powder) (a form of rust), that will not dissolve in acids (even aqua regia)...
4 FeCl2 + 4 H2O + O2 <-- --> 2 Fe2O3 + HCl
Or
heated too strongly
FeCl2 +H2O +1/4 O2 --> 1/2 FeCl2 + 2HCl
6 HCl + Fe2O3 + Fe --> 3 FeCl3 + 3H2O
6 FeCl2 +3/2 O2 + H2O --> 2 FeO.OH + 12 HCl
Then
4 FeCl3 + 8H2O --> FeO.OH +12 HCl
FeCl3 + 3H2O --> Fe(OH)3 + HCl
These iron oxides or hydroxides normally do not cause a problem with the gold recovery processes, the red iron powders do not dissolve easily and even gold can be dissolved from the red powder...
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=37&t=19816&p=203499&hilit=ferric+chloride#p203499
Here is another place you can use that waste solution, you have been waiting to deal with.
You can use the old waste solution, that old jug of copper chloride that has become more of an Iron chloride (from seeing to much iron in its use)
FeCL3 ferric chloride can etch copper in a two-step process:
FeCl3 + Cu --> FeCl2 + CuCl
Then
FeCl3 + CuCl --> CuCl2 + FeCl2
Silver normally will not dissolve in an acidic Chloride solution, as it oxidizes easily and forms a crust of silver chloride AgCl, which coats the silver protecting it from further oxidation.
But we can put some silver into a solution if we have a very High chloride content:
Silver chloride AgCl is fairly insoluble in water but if we heated it strongly in salt water NaCl (concentrating the solution) we can put some of the silver into the salt solution as silver dichloride soluble in the concentrated brine solution, upon dilution we would again get the insoluble white silver chloride {AgCl2 + H2O --> AgCl + Cl- + H2O} this is the similar to how we get a little silver in our aqua regia solutions.
AgCl + Cl- --> AgCl2
Ferric chloride heated with silver will etch the silver, this iron III chloride solution is aggressive when heated and concentrated, it etches silver plate slowly but effectively, and with plated silver it become very aggressive to the copper under the silver, the concentrated ferric chloride will hold some silver as AgCl2 and precipitate the rest as AgCl, it will also hold a lot of copper into solution as CuCl2 and CuCl, by dilution we can precipitate the CuCl and the little AgCl.
Ag + FeCl3 --> AgCl + FeCl2
Thin plated silver converts to silver chloride fairly easily, thicker pieces of silver can become coated with a protective crust of silver chloride, with this used Iron/ copper chloride solution being heated and concentrated strongly with agitation the silver crust on the silver can become broken loose by the mechanical agitation of the solution (process of the heat and stirring), this can expose fresh silver as the crust is removed converting more silver to AgCl as the fresh silver is exposed, in this many the thicker silver can be converted to silver chloride fairly effectively is one wishes to, it just takes a little longer in the process.
The CuCl white powders can be stored wet, and re acidified in HCl to make an etching solution of copper II Chloride later, leaving the little bit of silver as white powder
4CuCl + 4HCl + O2 --> 4CuCl2 + 2H2O
For the little bit of silver on buss bars or contact arms (silver contact removed) you can dissolve the silver with copper, the heavy bar will still have a lot of copper metal left you could sell as copper metal (you will dissolve a good portion of the copper weight though), for thin silver plate it will dissolve all of the copper.
Ferric chloride will also dissolve iron into solution if needed.
Do not expect to get much silver from buss bars, or from plated silver.
When your done with your waste solution, treat it and dispose of it properly, for those who have not studied how see dealing with waste in our safety section.
Butcher
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=11890&hilit=ferric+chloride
Kovar, An iron compound with about 54% Fe, 29% nickel, 17% cobalt, and traces of silicone, carbon, and manganese, usually used where they need strength or a springy metal.
Beryllium copper is another alloy used, where they need a spring metal or where strength or stress may prove a problem for the softer copper metal, where non sparking may be needed, or a non ferrous metal is needed, beryllium copper can have about 0.5% to 3% beryllium, and many time cobalt and nickel are part of the alloy.
Kovar with all of that iron is much more magnetic than beryllium copper, or the copper pins with a tiny bit of the weakly magnetic nickel plating under the layer of gold.
A strong magnet may attract the nickel, where a weaker magnet would not, and where the weaker magnet would only attract the iron in the Kovar.
If the copper is hard and springy, I would suspect beryllium, pure copper is fairly soft (will cut easy with a knife), and bends easily
In electronic scrap you will find these metals used where they are needed to better perform a function, or are needed to insure reliability, pins that may bend easy may use the stronger Kovar, contact may use beryllium to insure good contact, or for its springy nature, or to strengthen the pins from being bent out of shape by plugging in or unplugging connections…
This is a hard subject to explain but I will try.
Reuse of old copper II chloride leach that has become loaded with iron, and can actually become an iron chloride or and iron/copper chloride solution.
First lets look at what happens when we use our (AP) copper II chloride to dissolve Iron, we convert the copper II chloride CuCl2 (cupric chloride), to FeCl2 (ferrous chloride) and copper metal powders.
CuCl2 + Fe --> FeCl2 +Cu
Our solution during this reaction may actually have several copper and iron chloride salts involved before the above reaction is driven to completion.
Now once we end up with iron II Chloride FeCl2 (ferrous chloride) we normally think of our (AP) or copper II chloride as spent or waste, because FeCl2 is just about useless to attack copper.
But we can use this old spent leach solution to dissolve base metals, and actually we can reuse it to dissolve a heck of a lot more copper (not as FeCl2 but we can get FeCl3 from this solution).
Lets look at some iron chemistry to set up this discussion.
If we dissolve Iron (Fe) in HCl we can make ferrous chloride.
Fe + 2HCl --> FeCl2 + H2
This FeCl2 ferrous chloride will not readily attack copper.
But if let the acidic FeCl2 (ferrous chloride) set exposed in air for a long period of time it will absorb oxygen and oxidize to ferric chloride FeCL3.
4FeCl2 + O2 + HCl --> 4FeCl3 + 2H2O
we can speed this oxidation of ferrous chloride (FeCl2) to FeCl3 (ferric chloride) by adding about equal volumes of 3% H2O2 solution.
2FeCl2 + H2O2 (3%) + 2HCl --> 2FeCl3 + 2H2O
I have also found just strongly heating the solution also help it to absorb oxygen especially when the solution is concentrated.
Now Ferric chloride FeCl3 is a great etch for copper metals, hot concentrated solutions heated to a thicker solution, help to convert silver to silver chloride the heavy brine solution helps to remove the silver chloride crust that forms, gold is not attacked but plated gold will flake off as copper underneath is attacked.
Ferric chloride is used to etch copper circuit boards, just the same way the copper II chloride leach we call acid peroxide is used, the main reason to use CuCl2 cupric chloride leach over the ferric chloride leach to dissolve copper is the ease of which we can rejuvenate the cupric leach for reuse, in a copper cycle.
we can also rejuvenate the Iron chloride leach, but it is not as easy to get the copper back out of the leach.
I have stumbled on a way to use the ferric chloride leach (our old spent copper chloride leaches), by reusing my waste solution to dissolve base metals.
And actually make a copper II chloride leach from the copper I chloride powders in the process.
First we need to look at the two-step process of using ferric chloride FeCl3 to etch copper.
FeCl3 + Cu --> FeCl2 + CuCl
then
FeCl3 + CuCl --> FeCl2 + CuCl2
notice in the first part of reaction we can form CuCl, and later in the reaction the CuCl is oxidized to CuCl2, as the FeCl3 is reduced to FeCl2.
And in the second part of the reaction we end up with both iron and copper chlorides in solution as FeCl2 and CuCl2.
If we stop this above reaction in the middle we can separate most of the CuCl and let the concentrated solution cool and settle to powders of CuCl, AgCl and Au foils.
Returning most of the FeCl2 to the main reaction to help dissolve more copper as it picks up air (or we can add a little H2O2 to convert the FeCl2 back to FeCl3...
This is what I tried to explain in the post above.
Where I said:
I reuse this solution to dissolve copper and base metals.
Actually it become more of an iron chloride, if strongly heated you will be amazed at how much copper you can dissolve with this old used (AP leach), the iron chloride will dissolve pounds of copper in a corning dish on a hot plate when the solution get thick brown, decant a portion of the leach into a cooling jar there most of the copper will settle out as copper I chloride (a brown powder, unless diluted with water which will turn it white as acids are diluted) after settling you can return iron chloride liquid back to the corning dish to dissolve more copper,
The copper I chloride powder washed with a little water will give a white powder of copper I chloride this rinse liquid you can add back to the heated corning dish above to dissolve more copper.
This leaves you with the white copper I chloride powders, with some HCl add this dissolves and becomes copper II chloride, which can be used, as you know to dissolve copper, and if you had silver or gold on the copper you were dissolving above, you will be left with gold foils or silver chloride powders after adding the HCl.
So here we get our CuCl back to make a new CuCl2 leach solution (acid peroxide leach), we concentrate our old iron chloride solution (to treat for waste) giving us less waste to deal with.
And dissolve pounds of copper from things like contact points with chunks of copper that were cut from the relay or motor contactors, or gold foils from copper brass or iron pins...
Reusing a solution that was once considered a waste solution, to do more work dissolving pounds of copper, collecting a useful copper I chloride we can make into a fresh copper II chloride leach, and collect silver and gold, while reducing the left over waste solution to deal with.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=19838&hilit=ferric+chloride
Edited 5-30-2014 to update some information
So I bought it and started to work. The idea is the same as the idea in relays - get the contact points, refine and sell them with profit. The contact points here are made of silver - 999 purity (at least my data says so), the can be plated with Pd (in this case the have letter "A" written on the bronze, of they can be made of tungsten - letter "W", and I have heard legends about PtIr alloys. Here is what I did. First of all collect samples for pictures. After that get down to business - lost of time and efforts. Cutting edges can be boring and exhausting 
