Copper recovery rates

Those contacts might be worth taking the chunks of silver off the bars. Harold might pipe in, he would know best.

I rebuild my contactors by soldering a new blob of silver on.

looks like they are plated with thick layer of silver.

Assay a few contacts to figure out how much silver and copper you have, figure out the $$ value of each if the 2 were separated, see how much it would cost to do so, compare the resulting 'profit' to the mixed-content salvage cost.

There's gotta be ways to sep. silver from copper. They might be expensive in time or money or both, though.

Dave

I just wanted to know how much to ask for them from a scrap dealer.

In Seattle, clean copper scrap goes for $3 / lb. Dirty copper (insulation still on) goes for around $1 / lb.

OK, thanks Ernie, just the answer that I wanted. Thank you. Just tryin' to clean up a little, I have about 150 lbs of clean copper and

Never sell anything 'till you know what its worth.

Hello, my name is Dave, and Ima cheap bastard.

Dave

Sure. The cyanide process will work, not sure it is worth the hazards, unless you have 55 gal drums of the stuff.

I'm doing cyanide recovery of electronic gold scrap. I did a trial run with moderate success, I think I have the chemistry down and am setting up some gear to mechanize the process so I don't have to babysit it so intensively.

Unless the Hunt brothers pull another silver swindle, I don't think silver is worth the effort to do in house. Just sell the scrap to a refiner.

Jon

Hey, Ignoramus.

What the hell does Mexico have to do with your question?

Scritch

Ignoramus16482 wrote:

It's not that simple. There are various compositions of contacts----a few won't represent the average. Depending on the source, it could be very misleading.

You are totally misinformed. Cyanide reacts with copper almost equally as it does with silver or gold. It is not a recovery process that works economically. It hardly works at all. Silver is recovered from copper either mechanically of with nitric acid.

Your moderate success is due in part to a nickel barrier under gold. Without that barrier, you won't have good results. If you are not using a buffered cyanide solution, your success will be less than desirable.

There is a sulfuric acid process that will recover gold and silver from copper alloy with virtually 100% success, but it involves a water cooled cell and high amperage. No ferrous based items can be introduced. That's where the cyanide process shines----such as removing gold plating from watch bands, although many of them have top caps that are copper alloy.

All depends on what you call "worth the effort". If one has a supply of copper bars that have silver contacts attached, removing the contacts and extracting the values can be very profitable, indeed. It all depends on how much work you're willing to do, and how much you think your time is worth. Dealing with refiners tends to be a losing proposition------something I know from several experiences. Their fees often exceed the value of the precious metals involved. I won't go into their honesty, which is often suspect. Again, I speak from experience.

Do keep in mind that silver contacts are almost never pure silver. Many of them are a composite of tungsten and silver, making them weigh far more than their content in silver. They are also not easily refined, requiring a long boil in nitric acid and water.

Harold

Harold, you (as usual) know what you are talking about. So. How much copper (thickness) would there be on high voltage switchgear silver plated copper contacts?

I'm not sure I've ever seen anything quite like you describe. The contacts I've experienced (thousands of troy ounces, maybe tens of thousands of troy ounces---I kept no records) are typically silver composition soldered to pure copper buss bar-----and on many occasions silver plated after assembly. It's fairly rare to find copper contacts----especially for high amperage. Can you tell me how you've determined that yours are copper? If you'd like to send me a picture, feel free----but please keep in mind I'm on a dialup that connects almost routinely @ 26,400 bps. Please make the picture reasonable in size.

Harold

Harold, the contacts that I have are from high voltage high power switchgear and were mostly made by Allis Chalmers. They externally look just like old silver would, shiny with blackish spots on them.

I took one such contact and ground it with a bench grinder a little bit. Inside, a more yellowish/reddish material was seen, which I surmise is copper.

I will try to look much more closely tonight and will try to determine the thickness of silver layer. Maybe I could use a micrometer to gauge the initial thickness, and the thickness just barely after outer silver has been removed.

I surely can make pictures. I will not show them to the scrap dealers that are coming tonight.

Maybe the Mexicans buy wire with insulation and strip it to get the clean copper price. Just guessing.

Wes S

The Mexican people, unlike many of the spoiled residents of the US, are willing to take any job that is available. They are found extensively in areas that are considered less than great employment by the vast majority of our citizens, and provide services that are sorely needed. The scrap business isn't glamorous, although very essential to our very survival. Many of the Mexican people are found working in such jobs.

No, I am not of Mexican heritage, but I fully understand their plight.

Harold

Hi Harold,

Around here brand new fiber optic cable was pulled out of a underground runs. Copper coils hacked from air conditioners. I suspect there are phone numbers next to the metal claim desk now - direct line to the Sheriff.

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net TSRA, Life; NRA LOH & Endowment Member, Golden Eagle, Patriot"s Medal. NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member.

snipped-for-privacy@lycos.com wrote:

(thanks for correcting my goof on the silver via cyanide process. And, Technic's solution for Ag recovery is probably much less cost-effective than their Au solution.)

But, I am using a buffered cyanide (left that detail out). If left too long in the solution, it will start to attack the copper, but it is still pretty selective. Dealing with refiners tends to be a losing proposition------something I know

Thanks for that. I talked to a bunch of refiners some years ago, and got a funny feeling about that whole business. Thanks for confirming my feeling was right.

Jon

Great timing! That would be after silver hit an all time high of about $50/ounce, then fell back drastically. Today, you'd expect to pay no less than about $25/ounce.

Are you sure it's fine? It's not commonly used for jewelry, although not unheard of. I'd think it was sterling---92.5% silver, 7.5% copper. Great conductor, but not necessarily the best for arc resistance. Either way, you did good. There's a simple test to see if you have fine silver, if you have any doubts. A tiny drop of nitric acid and distilled water (don't use tap water----it has chlorine in it) applied to the material will dissolve a minute amount of the material and yield a clear solution that precipitates silver chloride (looks sort of like cottage cheese) when you add chlorine (table salt or HCL). If the solution remains clean, never turns blue/green, it's pure. If you slowly develop a greenish color, which turns blue after you're precipitated the silver, it's either sterling or coin silver.

Could be, but not because they can't do better. It's long been a theory about planned obsolescence. They expect you to buy replacement parts---which I can imagine is a large part of their business. Replacement parts are often priced thousands of a percent higher than their real cost. It could also be that the contacts you replace are like the ones I'll describe below, an alloy of silver and cadmium near as I could tell.

What's the advantage to the various alloys? Why don't they just use

I'm not a chemist, physicist or metallurgist, so I hesitate to reply, but for one, silver is quite soft. That's the reason it was alloyed with copper (10%) for coinage in our country. The combined elements are much tougher than either one alone------much like bronze.

Don't short change the idea that it's far more expensive than base metals, so they can stretch it nicely by alloying. That's particularly true in the case of 10K gold rings. If you understand the old marking laws, and the strategy that was used in compliance with the laws, you quickly come to understand that a 10K gold class ring, made before '75, was most likely really only 9K, which is illegal in the US. Nothing lower than 10K was considered solid gold, but tolerance in manufacturing allowed for the misleading marking, which made it legal. That is no longer true. They were allowed 1/2% for alloy variation, and 1/2% for solder, which, while gold, often is slightly lower in karat than the parent metal. Combined, they had

For the record, I processed enough class rings to know that what I say is very true. The yield always bordered barely above 9%, and I was very thorough in my processing----very little didn't report in the end product.

I realize that my stuff is light duty, low

Pretty much. I know for fact, due to having refined them in bulk, that many of the contacts are a composite of tungsten and silver, predominantly tungsten, which you quoted, above.. It's used for arc resistance as I understand it, but then, as I said, I'm not a metallurgist.

While I never analyzed contacts for all elements (wasn't necessary*), I believe that many of the smaller ones are alloyed with cadmium. Why, I have no idea, but it wasn't uncommon to process a batch of small contacts and come up with a surprisingly low amount of silver, and nothing else that was identifiable with the processes I used. Again, when you consider the value of each element, there are definite monetary advantages to alloying.

• Knowing what was present wasn't a factor. Silver is put into solution, then extracted with copper. Anything else present of low or no value remains in solution (zinc, copper, nickel, etc.). Gold can't be in solution with silver (not in acid), and any traces of other precious metals (platinum group) are precipitated along with the silver, so there's a complete recovery of values. The only thing that otherwise goes with the silver is the miniscule amount of base metal that is dragged down mechanically-----and that is removed in the final process---along with other values-----by electrolytic refining.

Harold