Matt Smith Posted February 1, 2014 Share Posted February 1, 2014 Ok all of this is hypothetical... currently pre 82 pennies are worth double their face value in copper at 95% copper 5% zinc. If someone wanted to smelt the copper out of them and separate the zinc could one do this simply through heating them? I know zinc melts at a lower temp than copper so would you be able to separate the melted zinc before the copper melted?. Now I know that it is illegal to deface currency and I also know the dangers of melting zinc... fumes.. positioning etc. I am just curious if this is a possible process. Maybe if one day the gov allow us the use of scrapping pennies. I know a lot of people are hoarding them right now. Quote Link to comment Share on other sites More sharing options...
njanvilman Posted February 1, 2014 Share Posted February 1, 2014 The mix is an alloy of the two metals. They will not separate just from melting. Think of bronze...usually a mix of copper and tin , and it does not separate when melting to pour art castings. Or brass, which is usually copper and 10% zinc. A chemist would have to chime in here to explain how to separate them chemically, if it is even possible. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted February 1, 2014 Share Posted February 1, 2014 also the cost to heat them, eats into your proffit margin. Brass can be different amounts of zink, 10% is for guilding metal, many types we buy are up to 37% tin, dependant on use. Quote Link to comment Share on other sites More sharing options...
Matt Smith Posted February 2, 2014 Author Share Posted February 2, 2014 So the only way to seperate is chemically? Quote Link to comment Share on other sites More sharing options...
Stefflus Posted February 2, 2014 Share Posted February 2, 2014 I was wondering if this couldn't be done with selective oxidation of a melt, so I did a google search. According to this PDF it can't, but they mention "Vacuum treatment" of the melt, what process is that? (page 11) http://www.metallurgie.rwth-aachen.de/data/publications/2333.pdf Quote Link to comment Share on other sites More sharing options...
oof Posted February 3, 2014 Share Posted February 3, 2014 If I took a hundred pound ingot of 95-5 copper/zinc to my scrappy, he would shoot it with the xrf and pay me for 95 pounds of copper and 5 pounds of zinc. He does the same when I carry a piece of mystery metal up to the counter to buy it. For example I was there a couple of days ago and grabbed a handful of "stainless" rod for pinning knife handles. When he shot them they were some alloy really high in nickel and going to cost $3 a pound instead of the normal $.75 so I didn't buy it. mark Quote Link to comment Share on other sites More sharing options...
Nobody Special Posted February 3, 2014 Share Posted February 3, 2014 Not saying I melted pennies before, but........I've had them well above zinc melting temps before without any appreciable deformation of the copper ones outside of some oxidation on the outside. A few copper ones not sorted properly from a bunch of zinc ones on the other hand, sometimes come out of the bottom of the crucible yellow and "brazed" afterwards. A cool looking, but probably stupid effect given the chances of getting seriously ill from doing this. I suppose if you melted the copper long enough, maybe some of the zinc would burn out or be given off as fumes. I seem to remember hearing that in professionally recycled brass, some of the zinc was lost when it was remelted. Either way, melting pennies at home without all proper precautions is a good way to get fume fever. Doesn't seem worth the risk to me, even to get copper. Quote Link to comment Share on other sites More sharing options...
Matt Smith Posted February 6, 2014 Author Share Posted February 6, 2014 I agree about fume fever.. nasty stuff. In all reality if one wanted to make money off of copper pennies you could hoard them until the gov allows them to be scrapped Quote Link to comment Share on other sites More sharing options...
Sweany Posted February 6, 2014 Share Posted February 6, 2014 melting pennies is illlegal Where? not all places have the same rules, the world is a big place. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted February 6, 2014 Share Posted February 6, 2014 sort of depends on what country you are in doesn't it Sweany? Quote Link to comment Share on other sites More sharing options...
Cross Pein Posted February 6, 2014 Share Posted February 6, 2014 In the USA, I don't think it is illegal. I see machines that squish pennies and press something on them at almost every tourist trap I visit. My wife collects them. (The pennies, not the machines.) Bill Quote Link to comment Share on other sites More sharing options...
DKLabs Posted February 6, 2014 Share Posted February 6, 2014 The way i had the law explained to me was really easy to understand. In the US you can do whatever you want to your money (cut, melt, deform, etc) as long as you don't try to use it as money after you do. Quote Link to comment Share on other sites More sharing options...
Nobody Special Posted February 6, 2014 Share Posted February 6, 2014 Had this argument once or twice. There have been laws on the books in the states against defacing money, primarily with the intent to keep people from say, scrapping $5000 in pennies for $15,000 in copper or zinc. They have gone on and off the books periodically, but even when they're in place, they usually on focus on people who are destroying large quantities of cash. Not some guy in the backyard that melts down two or three bucks in small change for a hobby or an art project. The big law otherwise is that you can't change money with the intent to defraud someone, and that one stays on the books. Quote Link to comment Share on other sites More sharing options...
Matt Smith Posted February 6, 2014 Author Share Posted February 6, 2014 I stated in my orginal post it was illegal... i was talking about if it could be done. not should it be done Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted February 6, 2014 Share Posted February 6, 2014 I've always found the new pennies to be useful zinc sources for small brass castings---nicely metered! Quote Link to comment Share on other sites More sharing options...
Neil Blythin Posted February 8, 2014 Share Posted February 8, 2014 You can always melt down another country's coins. We get quite a lot of US coins mixed in to our change here in Canada. I assume you'd find some of ours mixed in with your change too. Quote Link to comment Share on other sites More sharing options...
Chinobi Posted February 12, 2014 Share Posted February 12, 2014 I chased this down in pursuit of something else but it applies directly here so I thought I would share. I know you are already aware of the illegality of it, just wanted to cite the reference for posterity. plus, melting them down specifically to harvest them as a raw material was specifically illegalized on its own to prevent shortage and costs incurred to re-mint them, entirely separate from the clauses covering defacing and mutilation. it appears that the interim rule against melting down nickels and pennies was finalized in 2007 and is in effect http://www.usmint.gov/pressroom/?action=press_release&ID=771 "Specifically, the newly enacted final regulation prohibits, with certain exceptions, the exportation, melting or treatment of one-cent and 5-cent coins. Some of the exceptions allow for small amounts of these coins to be exported as pocket change, and for recreational and numismatic purposes. Other exceptions include the treatment of minor quantities of these coins for educational, amusement, novelty, jewelry and similar purposes. However, the public should review the regulation for precise terms and limitations of the exceptions." excerpt from the usmint link Quote Link to comment Share on other sites More sharing options...
VaughnT Posted February 26, 2014 Share Posted February 26, 2014 So it's illegal to melt the coins to recover the copper and zinc value, but you can still melt it to make mokume or similar foofaraw. Of course, all this would be moot if you weren't showing up regularly with ingots. One visit with an ingot that's reasonably similar to the chemical make-up of coinage isn't going to warrant close scrutiny. Repeated visits, or showing up with a huge ingot... that's another story. Is it worth the trouble? Personally, I hunt down old copper-tipped soldering irons if I want a big chunk of copper to play with. Quote Link to comment Share on other sites More sharing options...
Graham Gates(Ionic Muffin) Posted March 23, 2014 Share Posted March 23, 2014 even more practical would be to look through junk yards for things that have copper in them such as fridge pipes for water and other appliances that would have copper in them and get that from the junk yard, that is, if you could get it without paying an arm and a leg. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted March 23, 2014 Share Posted March 23, 2014 So it's illegal to melt the coins to recover the copper and zinc value, but you can still melt it to make mokume or similar foofaraw. Of course, all this would be moot if you weren't showing up regularly with ingots. One visit with an ingot that's reasonably similar to the chemical make-up of coinage isn't going to warrant close scrutiny. Repeated visits, or showing up with a huge ingot... that's another story. Is it worth the trouble? Personally, I hunt down old copper-tipped soldering irons if I want a big chunk of copper to play with. Few places will acept an angot, because it is too easy to fake its true content, all you need is accurate weight for size, coul be anything inside the ingot. I was also told that, with them paying the same amount for the origonal item as the newly manufactures shape IE the ingot, and it costs more money to heat to melt into an ingot, there is no reason to process unless it is to defraud them. Quote Link to comment Share on other sites More sharing options...
joehannah_108 Posted October 21, 2021 Share Posted October 21, 2021 1982 and older pennies w/ a copper to zinc ratio by mass of 95:5 will melt at 1024C. It's best to pour the metal into molds once the temperature reaches above 1120C. This will help make the pour much smoother and gives a nicer end result. This requires the use of a serious melting forge. Propane gas wouldn't get hot enough. After melting the pennies and pouring them into a graphite mold, they will need to be refined by electrolysis to crystalize out the pure copper while leaving the zinc and other impurities behind. Electrolyte of choice is copper sulfate which is very water soluble. You can find the entire procedure for electrolytic refining online. Instead of melting the pennies down, you can figure a way of refining them directly with electrolysis by using a vaccuum filter bag cell design. Check out Sreetips on youtube for silver cell designs. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 21, 2021 Share Posted October 21, 2021 Welcome; BTW that thread was 7 years ago! Also: propane gas can melt steel which takes a way hotter temp than copper takes; I've accidentally done it in my propane forge and saw a friend do it accidentally in his propane forge as well. Does there need to be a mention of "Check the last posting date of a thread" in Read This First? Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted October 22, 2021 Share Posted October 22, 2021 add t that the fact the OP has not been here in 3,5 years either Quote Link to comment Share on other sites More sharing options...
Cooterbobs.smelts Posted May 24, 2022 Share Posted May 24, 2022 On 2/2/2014 at 1:44 PM, Stefflus said: I was wondering if this couldn't be done with selective oxidation of a melt, so I did a google search. According to this PDF it can't, but they mention "Vacuum treatment" of the melt, what process is that? (page 11) http://www.metallurgie.rwth-aachen.de/data/publications/2333.pdf Yes this is true you have to retort zink oxide just like amalgam back to mercury but I DO NOT RECOMMEND THIS IF YOU DONT KNOW YOUR BASIC REQUIREMENTS AND CARE....... Safe poor Poor on Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted May 24, 2022 Share Posted May 24, 2022 Cooter; are you interested in smelting---taking ore and extracting metal from it or melting---heating up metal till it melts and then casting it. Your name seems to indicate one but your posts seem to be about the other. I've done some of both which is why I wanted to know. Quote Link to comment Share on other sites More sharing options...
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