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Recycling Metals

I was looking around the other night for information on how to separate metals through smelting, electrolysis, etc. I wasn't able to find much. I'm guessing this is still somewhat out of the range for the DIYer? My neighborhood typically has a rediculous amount of scrap metal on the curb, but the scrap yards around here only offer a slight profit on pure metal. Besides selling the metal at a scrap yard, how hard would it be to seperate the metal yourself, and just use it for your own purposes. I'm going to be investing in a metal-working lathe in the near future, and I'd rather reuse metal I've got lying around than buying it brand new at a premium. What do you guys think, is this doable?

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Rishnai9 years ago
You don't really need to separate things much, just melt. If you've got a chromed brass something, I can see why you might want to try and get the chrome off, but it's really not viable, even from a commercial angle. one will come to the top as slag, and the other will be pure. Sort by hand the types of metal, then melt, pour, and lathe. Ba-da-bing! You really only need smelting if you found an ore outcropping in your back yard!
Lorek (author)  Rishnai9 years ago
I was thinking of messing around with different alloys at some point and stock metal that I buy is usually measured by diameter with a huge markup for larger diameters. Do you know of any good resources on metallurgy in general.
Rishnai Lorek9 years ago
Other than my high school metalshop teacher? None for metallurgy in general, but I could probably come up with some on specific topics. So if you're going to be messing around with different alloys, it sounds like you want to know how to know precisely how much of each trace element you have? Or were you planning on determining the makeup of an unknown alloy you picked up on trash day a block away, then messing around with that?
Lorek (author)  Rishnai9 years ago
Making my own stock alloys if I have the ingredients would be nice or figuring out how much trace elements are in an alloy I have so I can use it for its specific characteristics would also work. Mainly, I like being self sufficient. Even if I don't end up doing it very often I like knowing how to do it. Else it'l bug me later.
Rishnai Lorek9 years ago
Hmm... well, it would probably be possible to build some kind of spectroscopy setup, but it seems like the best way to figure out what alloy you've got out of the trashpile is through physical properties. Each has different properties, most of which you can look up in welding instruction and tip books. The central branch of your local public library probably has a nice selection. The one I have (or had, lost it in a move years ago) would list what composition of welding rod to use with various metals in an easy to read table format. It would also give examples of what applications are most likely to use various alloys. There are only a few common ones for steel. You would need information on heliarc (TIG) welding if you want to know about something that contains aluminum. Some books also list physical properties of various alloys, such as tensile strength, color, luster, reactability, and melting point. So test those aspects of your mystery material, then look up the results. A well-worded google search might even yeild good results nowadays. As for making your own alloys, the best way I can think of is to start with a known formula that you have determined through physical tests/looking it up, and then use algebraic systems to determine how much of each raw material that you have will need to be combined to get your target recipe. I hope that made something close to as much sense as it did in my head, or I've just written two paragraphs of pure confusion...
The alloy bit simplified for human use...

- Find an alloy that you already know the formula of check online...
- Get metals necessary and weight out in the same ratios
- Bake until melted...
- Now it's just like cooking deadly and inedible pancakes...

To find out more about classifying mostly pure metals an easy way of doing it could be through density...

You'd need an accurate measuring item, like a beaker marked in mls
Along with that you'd need some pretty accurate scales

Weigh your chunk of metal, to the milligram, for smaller amounts at least one decimal place is a must.

add a very exact amount of water to your measuring jug, drop the metal in and record the change, that difference in mls is the difference in cubic cm, you can now work out density by using the formula: D = M/V

to you that's density = mass divided by volume

so 100g/cm3 would be = 90g/0.9cm3

To convert to cm3 is nice and easy if you have the measure in millilitres...

Once you have a good density you can look up the index of metals and check their density to find your match. You should repeat the tests three times to try and get the most accurate measurement possible...

You could find out the atomic weight and use a periodic table but that would be doing extra maths for nought.
A jackalope simplifying things for humans? Unheard of! I guess your way does mean 97.2% less having to remember college algebra, and 63% less algebra overall. Makes sense. But now I get to make up statistics, so it was worth it.
Yerp and it's low tech aswell...
tech-king9 years ago
i think if you heat them up, you can seperat impurities.
skunkbait9 years ago
I'd probably sort by hand and only use a furnace for really valuable metals. I always keep a junk car full of scrap metal around. When I need spare metal I've got it. When I've used all the good scrap and it gets too full of the worthless stuff, I haul it to the junkyard (minus gas tank of course). A good load goes for $300 or more.
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