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Author: Subject: Scrap metal recycling
Sedit
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Scrap metal recycling

Scrap metal prices have semi recently been on a steady rise and because of this and my access to scrap metals from work I have been making endss meet fairly well by taking in a variety of different materials mainly Copper, Iron brazz and Stainless steel.

At the moment the price of Brass has risen dramaticly and one can get $1.65 a pound or more at a junk yard. Given that you can fill a small bucket with roughly 100 pounds of Brass this has proven most helpful in these hard economic times. My question is where would be the best place to find a variety of other materials that could be scraped. For example old welders are some of the largest cash of Copper I have found to date. There are basicly a large transformer with very thich copper wires and flat copper sheets. At$2.50 a pound for Copper and the fact that they contain roughtly 100 pounds of copper wire you can see the profit that can be made thru a little bit of work stripping it down. Not including the Iron which has about 100 - 200 pounds of weight or more and currently is priced at .10cents a pound.

Computer parts are known to contain gold and other precious metals and I was woundering if anyone had data on how much per weight is needed to extract anything useful and exactly what parts of the boards contain the useful high priced materials. Since these are not taken at a normal junk yard it maybe be best to save these pieces up until I can extract a good amount myself to sell.

Ofcourse there are other materials such as lead, magnesium ect...ect..

I just wanted to hear your thoughts on what kinds of metals and where to find them.

Nickle is also one I would love to source as well since there are quite a few experiments I wish to perform using it. NiCd batteries are ofcourse one source but I'd like not to mess with the seperation of the cadium at the moment.

All in all I want to take this scrap recycling of mine to the next level and start to gathering as much money as I possibly can since I enjoy ripping shit apart anyway.

Also can anyone suggest a cheep solvent for the removal of the coatings from Copper wires? There is of course MEK or acetone but the bulk needed would make this very uneconomical unless a small amount in solution with something cheeper such as H2O for example could possibly be benificial.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
JohnWW
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If you are going to melt old copper wire down to cast into ingots, there is no need to use a solvent to remove the coatings from the stuff - they will simply burn off when the copper wire is heated. In fact, because the melting-point of copper is 1,083ºC, it should be possible to melt off, or failing that burn off, all possible organic coatings or coverings on copper wire, by heating to well under the melting-point. About 400ºC should be adequate, noting that the melting-point of polycarbonate plastics is about that.

[Edited on 31-3-10 by JohnWW]
Sedit
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No I have no real desire to melt the copper down since the energy requirements largely offset the potential profit way to much IE its not needed. However they pay about 20-40cents a pound for wire with the coating on it yet $2.50 a pound and up for clean copper wire. I have made a machine that can strip the coating off of single strand wire by compressing it thru rollers causing the wire to act as a blade and cutting the coating in half however I have a messload of thick multistrand cable copper wire that will not strip itself in this fashion. Someone who does this for a living said that the pay is good at 40cents a pound because the coating makes up the difference in weight so I stripped some down manually and proved to them that they where lossing ALOT of money by selling it this way since the coating only made up a small fraction of the total weight. I use to work as an engine mechanic for a yacht company and we went thru alot of extremely thick copper wire. The higher ups had a 55 gallon drum filled with MEK that they would toss all the scapes in and tap off the solution after all the coating dissolved getting over$1000 at a time sometimes for the copper that it contained.

They where using MEK bought by the company and they where technicly stealing the wire at that so economics wwas not much of an issue to them but for me however this is a problem.

I want to avoid burning since this is highly toxic and some of the places I sell to are picky about this sort of thing and may refuse to buy it because the DEP may come down on them.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
franklyn
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There are quite a few different types of magnet wire enamel insulations.
http://en.wikipedia.org/wiki/Magnet_wire
They are all organic polymers and even those having the highest
temperature resistance will melt or decompose by 300 ºC.
This leads me to think that immersion of the wire bundle in a molten
inorganic salt bath should strip off any coating.

An alkali halide blend LiCl 58.8 % with KCl 41.2 % melts at 352 ºC
Note that this is very precise , a mixture of LiCl 55 % and KCl 45 %
melts at about 430 °C

.
bbartlog
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Stripping via decomposition at 350 ºC is probably not much better than burning when it comes to producing noxious vapors. Might also increase costs depending on the scale of the operation and the method of heating. So far as finding a halide salt that is liquid near 300 ºC, it would be easier to use straight zinc chloride than to try to get the LiCl/KCl eutectic mix just right. I suspect it would fume a bit (even without adding the insulation) but this method would require dealing with fumes in any case.
bquirky
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ive sugested sompthing simalar in another thread so i might sound like a broken record but why not electro plate it over ? the oxidistion on the anode will destroy the insulation and the cathode will be dense (relitive to a bundle of wire) and clean of debri

allso, do scrap metal merchants sell to the public ? at some point soon im going to want several ten's of Kg of copper and zinc and i think a scrap dealer may be my best bet.
Fleaker
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Many scrappers would prefer wire over copper ingot. I could say all scrapyards, but I don't know all of them. The reason is quite simple: wire is in a form that has a certain minimum purity (99%<. This is true of almost all metals. Most big scrap yards have the point and shoot XRF guns.

Also, having melted many kilos of copper--it's very, very hard to pour nice clean copper unless you're very careful.

sedit, and any interested in recovery of gold and other precious metals from scrap sources are well advised to check into this forum: http://www.goldrefiningforum.com

Neither flask nor beaker.

"Kid, you don't even know just what you don't know. "
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Sedit
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Fleaker thank you that link is great I'v been trudging thru there forum since you posted it. I have a good amount of computer parts for this very reason and have been saving for a while and will continue to do so.

I doubt my buyer would take ingots for any kind of value and will more then likely put a "lite" tag on it causing it to lose much value. Most copper I take in is in the way of tubing since plumbing is my job. Brass as well in the form of valves.

Anyone have experiance with metals like magnesium or things of that nature?

I recently decided to start taking motors apart since the price of them dropped thru the floor for some reason only fetching .03 cents a pound where as light iron gets .10 cents a pound. The tops and bottoms are Cast Al and the wire inside can be removed very easy with a sawzall. Now I get about 2 pounds of Cu wire(assuming the wires not Al ) and some iron as well.

Any suggestions on other things that I should chop into pieces for max value?

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
Mildronate
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whay you need a machine that can strip the coating off. You can simply burn all coating in fire.
Sedit
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Its againt the law.
It lowers the price of the material.
And most important some places will not take copper that has been burned. And yes it is obvious when it is burned because it leaves a black char that not even HCl removes cleanly.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
Mildronate
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In my country every bum do it with burning.
1281371269
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The forum is very interesting - I have an old processor lying around and if I can get a couple more I'll try getting doing an extraction on them at some point. If I managed to make 0.1g of Gold - enough for my balance to pick up - I'd call it a great success.

But the forum is also confusing. For example, what are 'fingers'? There're plenty lists of sources, reactions, tests, etc and individually they all make sense, but I can't find anything that gives a step by step, detailed process for a first timer trying an extraction.

So using mainly common sense with some chemistry thrown in, I've devised a method:
Get gold containing material into small pieces
Eliminate everything possible (react with H2SO4, neutralise, dilute, filter off solids, react solids with HNO3, neutralise, dilute, filter off solids)
One could now extract silver form the filtrate by displacing it with fine Cu powder
The reside will be a mixture of gold / other noble metals and anything insoluble that doesn't react with acids or oxidisers
Then extract the gold from that via, say, aqua regia
Collect the liquid bit (filtering would be an issue unless you had glass filter paper) and evaporate collect your Au

Does that sound feasible?
Mildronate
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To my mind its to expensive. You can maybe sell parts of your old pc and get biger money. How about platinium from cars exhaust pipes?
1281371269
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Sure, I wasn't expecting to profit from it.

Only high range cars will actually have platinum catalytic converters anyhow, and if you managed to get your hands on one it would probably be worth more sold on.
Sedit
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Mossy just for the hell of it I tossed the "fingers" AKA gold plated connections that are on the end of the cards that slide into computers into H2O2+HCl . Instantly gold started floating to the surface quick as can be so you can expect how excited I am that I can see the gold from such a small scale experiment.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
chochu3
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If you need to burn copper wire, use kerosene to burn off the plastic this will not melt the copper if you watch it and turn it now and then. Their will will be a little hint of it being burned but the copper will still look shiny.

\"Abiding in the midst of ignorance, thinking themselves wise and learned, fools go aimlessly hither and thither, like blind led by the blind.\" - Katha Upanishad
1281371269
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I have a bunch of useless components, so I'll give it a go. If it looks gold, does that mean it actually is (plated)?

I did a nice experiment today - had a collection of old english shillings and florins from the 1900s. Anything between 1920 and 1947 is 50% Ag (mass) so I tried extracting it. Dissolved a few coins in HNO3, then boiled off the acid and swirled around some Cu wires in the mixture. My result is a good few grams of Ag powder, currently drying on a filter paper.
Unfortunately I messed up with about half the Ag / Cu nitrate mix (long story) and ended up with a black splodge, but I've redissolved that in HNO3 and will get the silver out at another point.
Sedit
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The silver will precipitate from the solution with the addition of NaCl solution. It precipitates Silver chloride which you may already know.

Iv been toying around abit myself but its to late for me to go into detail right now but the general consensus is if it looks like gold.... it prob is. At the very lest its gold plated and Im having alot more floating around in my solutions of peroxide/HCl to dissolve the base metals then I honestly thought I would. I know a couple people that repair computers and what not so this honestly could prove more profitable then I could have ever hoped for.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
1281371269
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I'm hesitant to say profitable but it definitely could yield a few grams of gold for use in making interesting compounds / to pretend to people you've discovered the secret of alchemy.

It might be hard to find buyers -I've heard that if you wanted to sell the gold to jewellers you'd have to prove its purity, which probably would be an expensive process?
Sedit
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No any respectible place will have an assay machine that uses X-rays IIRC that can determine purity rather quickly.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
weldit
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Sedit i'm assuming you are talking about the hand held x-ray gun they have in scrap yards. They cost 34,000 USD and do not do precious metals. The software for that is an upgrade and i know of no scrap yard that has the software.
I have extracted several ounces of gold from scrap computer parts and the biggest problem was finding someone to buy it. In my area there is only one place and i found out that he is not reputable. If you do extract any precious metals the best place to sell it is everybody's favorite auction site.
If you are extracting the gold and silver for profit you can make more money selling the chips and other parts on ebay. On that site they pay very high prices for the parts with no way of breaking even. For example the ceramic chips have about 2 grams of gold per pound of chips. Go to the web site and see what they are paying for the chips. It will be more than the price of the gold. I know there is some silver also and a trace of platinum in some chips but unless you are doing the extraction for fun it is more profitable to just sell the parts. If you look at who is selling the larger lots it is scrap yards.

Silver- After you precipitate your silver with NaCl or HCl it may not be pure AgCl. There may be some Pb or Hg impurities. To purify this dissolve the AgCl in ammonia. Pb and Hg will not dissolve. Once the AgCl is in solution and any insolubles have bin filtered off you can precipitate the AgCl with HCl

Mossydie you can only use copper to force the Ag out of solution if you know all the ions in solution. Using Cu will not only cause the Ag to precipitate but any other metal ion more electronegative than copper such as gold, platinum, palladium.
1281371269
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But such metals wouldn't have reacted with the HNO3 in the first place.

I like the ammonia idea. Does it have to be conc.? - if so it would be difficult to filter.

When I search 'gold computer scrap' in eBay.uk I get a load of international results but nothing in this country. I guess it just hasn't caught on here yet

But honestly, for the time it took me to remove the pins from the boards, open up the cpus, cut off the fingers, etc etc I would be far better off if I'd done some babysitting or something. And that's only for about 1oz of scrap. So it's definitely only as a bit of fun - how would one actually make money out of this?
Sedit
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"So it's definitely only as a bit of fun - how would one actually make money out of this? "

Just like the bigboys do, they showed on TV that what they do is grind the entire boards, chips ect into a powder and apply a static charge onto the dust. At the end of the conveyor belt is something that produces that charge causing the metals being conductive to just drop in the bin where the plastics and fiberglass fly off. I could picture a home job of a setup like that but you still need alot of scrap to produce a small amount.

I seen on Ebay someone selling 28 grams of the pins no solder or nothing for 14\$ so I understand what weldit is saying.

I honestly believe the best way to sell the gold would be to make shot out of it by pouring the melted mass in cold water and putting in vials for element collectors and other hobbiest. Surely you would get more then the value of the gold and it would reach a wider market.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan

 Sciencemadness Discussion Board » Fundamentals » Miscellaneous » Scrap metal recycling Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues