Random
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Copper wire impurities
I had some wire that had copper color, so I think it was copper, but it was a little bit more brown than orange like other copper wires.
I put that wire into HCl and was adding small amounts of NH4NO3 to dissolve it. Then after two weeks I removed that leftover wire (It was thick wire
so It didn't get dissolved completely - now it was very thick). I had very dark brown solution with color of copper complex. Then I started adding
sodium bicarbonate. Acids were neutralizing and soon they become less concentrated. White solid precipitated. I continued to add NaHCO3 and I
precipitated all CuCO3. I left the solution in a big canning jar thinking the white precipitate was CuCl.
Today, I think I saw some blue copper oxychloride floating on the (blue!?, copper chloride solution should be actually green) solution and I have
thrown all that water on the precipitate because it didn't seem to react with NaHCO3. Then I filled it with fresh tap water to the top. I saw a good
amount of another precipitate which definitely wasn't copper. It settled faster than copper carbonate because there was more of it at the bottom. Now
it is yellow like in the middle of this picture, maybe brighetr yellow:
This also isn't iton because it's heavier than copper (as I see) and it's yellow, not orange brown. I poured some blue solution on earth and it became
oily and the stones that were on earth got metallic color!?
What could be that precipitate? Silver, bismuth or something very toxic?
[Edited on 8-5-2011 by Random]
[Edited on 8-5-2011 by Random]
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unionised
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Copper (I) oxide is yellowish.
This
". I had very dark brown solution with color of copper complex. " suggests that you had a mixture of Cu(I) and Cu(II) in the solution.
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IrC
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I have noticed the bulk of the copper wire I have been working with in the last few years has serious problems when trying to get solder to flow
properly. I attribute this to wire produced in China where the metal is so damn impure it will not solder, or will only partially solder. It oxidizes
very quickly and it is easy to tell it is not all copper. In fact it appears there are impurities in the copper we get lately which makes soldering
virtually impossible. The resistivity is bad enough I do not doubt within a couple decades new buildings burning down due to faulty wiring caused by
this crappy copper will be a well known fact.
I should add it is easy for me to notice as I have been soldering things since the late 50's and the difference is striking. This cannot be attributed
to modern lead free solders as I have more new old stock of the good stuff (i.e., anything other than bi solder) such as 63/37 5 core and various
others than I will use in this life. In short there is something very wrong with all the new copper wire coming out of China. I bring this up since it
seems to me this could relate to the unexpected results seen by Random.
[Edited on 5-8-2011 by IrC]
"Science is the belief in the ignorance of the experts" Richard Feynman
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Sedit
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A couple years ago during the olympics China bought all of our Cu scapes for a very high price. There is odds that what your seeing is just a shitty
recycling job where they are selling us back our own scraps as wire. Much Brass and Aluminium get mixed into the scraps on accident before they are
shipped out. If they did not bother to purify this copper you can expect trace amounts of these materials in it.
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
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Morgan
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Some copper springs and such have a bit of beryllium in them. And I haver read some stories of scrap radioactive metals finding their way back to the
US in common everyday items. No telling what goes in the melt.
You could make a long list of why buying certain products made in China is blatantly hazardous to your health.
http://en.wikipedia.org/wiki/Beryllium_copper
[Edited on 8-5-2011 by Morgan]
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The WiZard is In
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Quote: Originally posted by Morgan | Some copper springs and such have a bit of beryllium in them. And I haver read some stories of scrap radioactive metals finding their way back to the
US in common everyday items. No telling what goes in the melt.
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From Wiki P —
http://en.wikipedia.org/wiki/Radioactive_scrap_metal
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unionised
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Does anyone here know enough metallurgy to confirm my suspicion that even small amounts of impurities in copper make it much harder and therefore
difficult to draw into wire?
If so then, while I understand the fun of bashing China since Russia gave up being the bogey man, I think it's at least as likely that the issue is
lead free solder and / or rosin free flux.
A sensible thing to do would be to measure the resistivity of the copper wire; it's a fairly sensitive test of the purity.
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Neil
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Impurities in copper - Many metals do affect the ductility of pure copper.
@ IrC: I've also noticed a increase in the difficulty of soldiering new copper wire over old. I have a treasured roll of the old lead 'good stuff' and
several rolls of varying composition lead free electrical solider and all have difficulty with the new wire. I've noticed that if I am scavenging
pieces from cheap dollar store electronics it's even worse.
I had a strange experience when I attempted to use some of the new wire to make copper beads. I heated an end of the wire with a propane torch but
instead of the wire melting and forming a bead, it partially melted and sparked a little bit - just like molten iron in a slightly oxidizing flame, I
can't say that I've ever seen copper spark before .
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Morgan
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A bit off-topic but if you have some straight lengths of half inch or inch diameter copper tubing, like 6 or 10 foot lengths you buy at the hardware
store and heat them very hot the strength of the tubing after it cools is strikingly weaker, same with the copper fittings.
Perhaps if you have some stiff copper wire, you could heat treat/anneal it to make it softer.
I recall reading about tempering some metals to make them very hard. They quench/cool them as quickly as possible, and I found it interesting that
mercury is sometimes used for certain applications.
And as for bashing China, a lot of American brand names are made in China, and I often wonder if the 18/8 SS pots and pans I have have any odd trace
elememts that could leach out. Maybe I'm just paranoid. A few days ago on the news I saw some very sick employees who used hexane to clean the screens
of the iphones they manufacture over there. They really don't care how they treat their workers and you have to wonder how much they care about the
safety of their products.
A few good tidbits in the latter paragraphs.
http://www.copper.org/publications/newsletters/innovations/1...
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Neil
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Have you ever heard of the Radium girls?
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Bot0nist
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Think I saw it on "1000 ways to die." Used a florescent, radioactive paint to make glow in the dark watches and straightened the tips with there
lips.. All died of isotope poisoning.
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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Morgan
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http://en.wikipedia.org/wiki/Radium_girls
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Morgan
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Poisonous Toothpaste: The FDA recently found that several low-priced toothpastes imported from China contained diethylene glycol, which poisons the
liver and kidneys and depresses the central nervous system.
Poison Pet Food: Two Chinese companies intentionally exported contaminated pet food ingredients to the United States, killing hundreds of American
pets that ate the food.
http://money.cnn.com/2007/08/02/news/companies/china_recalls...
"Hexane, a byproduct of gasoline refining, is used in the food business as a solvent to separate the oil from the protein and fiber of grains,
including soy beans."
http://www.foodsafetynews.com/2010/04/concern-over-neurotoxi...
"By summer, she was admitted to hospital, where doctors struggled to diagnose the cause. "I was terrified. I feared I might be paralysed and spend the
rest of my life in a wheelchair," she said.Because she was using n-hexane directly, she was one of the first and worst affected."
http://www.guardian.co.uk/world/2010/may/07/chinese-workers-...
[Edited on 9-5-2011 by Morgan]
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Random
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It looks the main impurity is iron because orange-brown stuff deposited on the jar. It's that chinese people are doing that with metals, the prices of
copper are actually higher now and the quality is lower.
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