Sciencemadness Discussion Board

cheapest aluminium metal sources?

math - 6-9-2012 at 16:12

Hello,

I'd like to know what are the cheapest sources for aluminium metal. I've been using Al foil for food, but I think there should be some cheaper alternatives.


Thank you

99chemicals - 6-9-2012 at 16:14

Go to your local scrap yard and ask to buy aluminum.

kristofvagyok - 6-9-2012 at 16:27

Scrap yard +1.

P.S.: aluminium foil is not pure, if it would be from pure Al it wouldn't spark if you would "test" it in your microwave oven. The kitchen Al foil contains iron, Ni, ect, so it's NOT pure.

AirCowPeaCock - 6-9-2012 at 17:14

Neither is a lot (most) "Al" you would get at a scrap yard. Alloys are every where, it's hard (almost ImpossIble) to find any metal that is not an alloy these days.

bbartlog - 6-9-2012 at 18:15

If you need high purity Al then aluminum electrical wiring is a good bet. Has to be high purity in order to have an acceptable electrical conductivity.

AirCowPeaCock - 6-9-2012 at 18:28

Interesting, what impurities are the issue? Iron from Bauxite? Silicon from Aluminum Silicate? Calcium from the Hall-Héroult process?

[Edited on 9-7-2012 by AirCowPeaCock]

food - 6-9-2012 at 21:40

I looked into this a while back

this is from a Reynolds faq item, about a year ago:

"Today, Reynolds Wrap is made from 8111 alloy aluminum, at the thickest gauge specifications available in the marketplace. Reynolds Wrap® Aluminum Foil is 98.5% aluminum. The balance is primarily iron and silicon. These are added to give the strength and puncture resistance obtained only in the alloy used in Reynolds Wrap® Aluminum Foil."

this is interesting re. aluminium wire:

https://www.rtapublicsales.riotinto.com/En/OurGlobalNetwork/...

http://www.mwswire.com/specialalum.htm

Hexavalent - 6-9-2012 at 22:55

The technology department at my school gives me all the pure aluminium shavings I need, collected from the bottom of the lathe base.

99chemicals - 7-9-2012 at 02:04

Quote: Originally posted by Hexavalent  
The technology department at my school gives me all the pure aluminium shavings I need, collected from the bottom of the lathe base.


I was going to mention that but, usually when cutting al lubricants are used an those would seem to be a mess to clean.

Endimion17 - 7-9-2012 at 05:22

Stiff electrical cables are very cheap sources of high purity aluminium. They contain several thick wires wrapped in a helix. There's some powder inside; I suppose it is used to rubberize the metal more easily. It's easy to unwind the thick helix and then snap the wire into bits. All you need to do it a quick wash in dilluted hydrochloric acid, rinsing with tap water and distilled water. It's somewhat entertaining to destroy a large cable to make a bottle of aluminium chips.

I don't know what metals are in a coaxial cable, but that foil inside reminds me of aluminium.

[Edited on 7-9-2012 by Endimion17]

Swede - 7-9-2012 at 05:28

Any aluminum you are going to find at a scrap yard, or via lathe turnings, is going to be an alloy, and some of them have significant amounts of metals other than Al. For example, 7075 Al...

7075 aluminum alloy's composition roughly includes 5.6–6.1% zinc, 2.1–2.5% magnesium, 1.2–1.6% copper, and less than half a percent of silicon, iron, manganese, titanium, chromium, and other metals.

Maybe some coarse pyrotechnic aluminum might be reasonably pure. Another source might be the soft and crappy aluminum structural extrusions like you'd find at a hardware store. It's still going to be an alloy, but more Al as a % vs. alloys like 6063. Pure Al is stupid soft and weal, hence the alloying that goes on at the factory to make the metal stronger and harder.

watson.fawkes - 7-9-2012 at 06:17

Quote: Originally posted by Endimion17  
Stiff electrical cables are very cheap sources of high purity aluminium.
These are in the 8000 series of Al alloys, which series is for "other alloying elements". I was looking at this yesterday, but couldn't find much other than the main alloying elements were Fe and Ni. What was easier to find is that the design goal for the alloy was to reduce the thermal coefficient of the wire. This makes electrical contacts more reliable and greatly reduces fire risk over the old 1350 alloy previously used four decades ago and more.

In any case, DIY stores in the US carry this wire as conductors within "service entrance" cable. Go to the cut wire section and ask for it.

Endimion17 - 7-9-2012 at 08:03

Quote: Originally posted by watson.fawkes  
Quote: Originally posted by Endimion17  
Stiff electrical cables are very cheap sources of high purity aluminium.
These are in the 8000 series of Al alloys, which series is for "other alloying elements". I was looking at this yesterday, but couldn't find much other than the main alloying elements were Fe and Ni. What was easier to find is that the design goal for the alloy was to reduce the thermal coefficient of the wire. This makes electrical contacts more reliable and greatly reduces fire risk over the old 1350 alloy previously used four decades ago and more.

In any case, DIY stores in the US carry this wire as conductors within "service entrance" cable. Go to the cut wire section and ask for it.


Ah, crap... :(
I never did chemical analysis of this wire, but I don't remember concentrated solutions in hydrochloric acid ever giving even mild color which would account for iron and nickel. Maybe it's just traces?
Also, unlike aluminium foil, which after dissolving in acid gives dark grey insoluble flakes, such wire was always giving a clear solution, and upon adding a base, typical white gel-like precipitate would form.

Most of amateur chemists don't require pure aluminium. After all, it's pretty much all about thermite and hydrogen.

MrHomeScientist - 7-9-2012 at 08:05

I've also heard that Al electrical wire is high purity, for best conductance. Even if you could only find alloys, could you not separate the Al from other metals by exploiting its amphoterism? I.e. dissolve the Al in NaOH solution, and most other metals should drop out as hydroxides. Not sure how you would get back aluminum metal from the sodium aluminate formed, though. Perhaps electrolysis, like how it is produced industrially (the Hall-Heroult process)? It'd be a hell of a task building such a cell, I imagine.

watson.fawkes - 7-9-2012 at 08:55

Quote: Originally posted by Endimion17  
I never did chemical analysis of this wire, but I don't remember concentrated solutions in hydrochloric acid ever giving even mild color which would account for iron and nickel. Maybe it's just traces?
Well, these 8000-series alloys are required for building code compliance in the US. I don't know if they're required elsewhere in the world. The 1350 alloy is 99.5% Al, with the rest as Fe and Si (as I recall from reading yesterday). I was a bit surprised not to find alloy composition for the 8000 alloys I was looking for, but I did get the impression that alloying elements were fairly small.

I'll correct an omission of mine from before. If you want very pure aluminum metal, go to a metals supplier and get some Al alloy 1099. This is 99.99% pure Al. It's only used in specialty applications (such as bus bars) because it doesn't have good mechanical strength over alloys and it requires a certain amount of fabrication care. The "0" designator in that alloy number means that there's no alloying agent added intentionally. You can think of 1099 aluminum as being the technical grade chemical coming right out of the foundry, before alloying modifications.

99chemicals - 7-9-2012 at 11:16

hmm. I do not know what the content of Al heat sinks are but I doubt that they have much to make them stronger.

Any body know If there is an alloy in them? Perhaps some copper?

Swede - 8-9-2012 at 04:36

Those heat sinks are going to be alloyed, and most of them anodized to boot. You could strip the anodize with an alkali, but again, I'm pretty sure they'd be a harder Al alloy.

I like the AL1099 suggestion.

Does anyone think my notion for coarse, bright pyro aluminum might have merit? I'd think they'd make the stuff using ingots straight from an Al foundry. There'd be little point in alloying it first.

AirCowPeaCock - 8-9-2012 at 07:15

I'm pretty sure the -325 mesh bright Al and -80 mesh flake Al I have is from alloys. Pyrotechnic magnalium and magnesium is known to sometimes ruin color because it's made from alloys. I think most pyrotechnic Al is going to be made from scrap. But, pyro dark Al like German dark and Indian Blackhead are made to high specifications and theirs a huge international market for them in everything from spaceflight to fireworks to military. I bet quality is not compromised for price in this Al--it's probably made from the best Al they can get (within reason) although that may mean it is an alloy, it probably doesn't. I would think pyro dark Al is 99.9%+ purity. Don't take my word for it though.

SM2 - 8-9-2012 at 11:55

How about cans? Classically, Al factories were located at Niagara Falls where the cheep electricity made electrolyzing the bauxite even cheaper. I think there are many ways to get Al for free/next to nothing. Don't forget your labor costs. And don't forget, most Al's are alloys - as others have pointed out, if that makes a difference to you. If quality consistency is important for you, you can ask best quote for ingots, and or/shavings. Best.

barley81 - 8-9-2012 at 12:15

"German dark" Al is coated with charcoal (or so I've heard).

Hexavalent - 8-9-2012 at 12:19

Quote: Originally posted by barley81  
"German dark" Al is coated with charcoal (or so I've heard).


Would it be stuck on in any way?

Could you add some to water, swirl and pass through a sieve or decant quickly to remove the suspended carbon?

BTW, this guy;

http://www.youtube.com/watch?v=EIkhTb-m2cM&feature=plcp

says that the darkness has to do with a difference in particle shape. See 2:59.

hyfalcon - 9-9-2012 at 05:34

I don't think water and fine aluminum powder gets along very well.

rivetboi - 1-10-2012 at 14:27

Quote: Originally posted by watson.fawkes  

I'll correct an omission of mine from before. If you want very pure aluminum metal, go to a metals supplier and get some Al alloy 1099. This is 99.99% pure Al. It's only used in specialty applications (such as bus bars) because it doesn't have good mechanical strength over alloys and it requires a certain amount of fabrication care. The "0" designator in that alloy number means that there's no alloying agent added intentionally. You can think of 1099 aluminum as being the technical grade chemical coming right out of the foundry, before alloying modifications.


All 1XXX aluminum alloys are 99% pure. I think the pure wiring alloy you are thinking of is 1199, the high conductivity oxygen free alloy. It is 99.99% aluminum with the remainder being mostly iron, silicon, copper and magnesium. For finer purity aluminum there are sputtering grades. The most pure i know of is 6N High Purity Aluminum. It is 99.9999% aluminum and is made through and for vapor deposition. You can buy a 2.2 lbs (1kg) bag of 6N pellets from Laurand Associates (http://www.laurand.net) for $1550 plus $50 s&h. Not so cheap but very pure.

For the pretty pure but cheap, try getting the 1100 from McMaster-Carr (http://www.mcmaster.com). It is 99.9% aluminum with no silicon or iron and they sell a 6"x6"x.125" sample block for $5.68 + s&h.

phlogiston - 1-10-2012 at 14:56

Perhaps sacrificial anodes for ship hulls?

S.C. Wack - 1-10-2012 at 15:31

Quote: Originally posted by rivetboi  
For the pretty pure but cheap, try getting the 1100 from McMaster-Carr (http://www.mcmaster.com). It is 99.9% aluminum with no silicon or iron and they sell a 6"x6"x.125" sample block for $5.68 + s&h.


I wasn't going to say anything because it's not perfectly on-topic, but geez get the 1100-H14 sheet at onlinemetals. Shipping is UPS and also not cheap.

watson.fawkes - 2-10-2012 at 08:12

Quote: Originally posted by rivetboi  
All 1XXX aluminum alloys are 99% pure. I think the pure wiring alloy you are thinking of is 1199, the high conductivity oxygen free alloy. It is 99.99% aluminum with the remainder being mostly iron, silicon, copper and magnesium.[...]
For the pretty pure but cheap, try getting the 1100 from McMaster-Carr
The point about 1XXX alloys is true. 99% is perfectly fine for a number of applications. If that's good enough, then 1100 would do you fine. McMaster carries it; OnlineMetals.com does not stock it, although I'm sure they could get it for you for a price.

The alloy 1350 was the alloy most common in residential, in-wall wiring. 1199 makes good wire, but it's not what was in trade. I'd image that there's plenty of 1199 used in high-energy physics equipment.

Here's a document on 1XXX alloys from Alcoa that describes their three most common alloys: 1060, 1100, 1350.

S.C. Wack - 2-10-2012 at 12:54

Quote: Originally posted by watson.fawkes  
OnlineMetals.com does not stock it, although I'm sure they could get it for you for a price.

More proof that I literally can't say the simplest, most obvious truths here without "a credible person" saying simple, obvious lies in response. Fuck this.

[Edited on 2-10-2012 by S.C. Wack]

watson.fawkes - 2-10-2012 at 21:10

Quote: Originally posted by S.C. Wack  
Quote: Originally posted by watson.fawkes  
OnlineMetals.com does not stock it, although I'm sure they could get it for you for a price.

More proof that I literally can't say the simplest, most obvious truths here without "a credible person" saying simple, obvious lies in response. Fuck this.

[Edited on 2-10-2012 by S.C. Wack]
Here's the quotation from their own web site, extracted from http://www.onlinemetals.com/aluminumguide.cfm:
Quote:
OnlineMetals.com currently stocks eight alloys of aluminum in various shapes and sizes:
2011 Aluminum (available in Hex, Round)
2024 Aluminum (available in Hex, Plate, Rectangle, Round, Sheet, Square, Tube)
5052 Aluminum (available in Sheet)
6061 Aluminum (available in Angle, Channel, Hex, I-Beam, Pipe, Plate, Rectangle, Rectangle Tube, Round, Sheet, Square, Square Tube, Tube)
6063 Aluminum (available in Angle, Channel, Pipe, Rectangle, Rectangle Tube, Round, Square Tube, Tube)
6101 Aluminum (available in Pipe, Rectangle)
6262 Aluminum (available in Hex, Round)
7075 Aluminum (available in Hex, Plate, Rectangle, Round, Sheet, Square)
Funny, I didn't see any 1XXX alloy there. So, should I disbelieve their own words?

Eliteforum - 3-10-2012 at 01:57

Ebay. Seriously

Arthur Dent - 4-10-2012 at 04:54

I have literally a drawer-full of aluminium heat sinks from various defunct audio devices and computers, some of them quite old. I wonder if there's a quick chemical test to determine the purity of the aluminium before grinding down one of these sinks?

Come to think of it, I might also have some of the big electrical "bus" bars described above.

I also have many copper heat sinks, but they scare me since I learned that many of those copper blocks contained some beryllium, and I know that airborne beryllium dust is WAY nasty. No saw, drill or dremel for those!!!

Robert

S.C. Wack - 5-10-2012 at 17:05

Quote: Originally posted by watson.fawkes  
Here's the quotation from their own web site, extracted from http://www.onlinemetals.com/aluminumguide.cfm

Anyone else would not be looking for supportive quotes, though, and those who instead go to their front page would notice

Be sure to take a look at our newly-arrived materials:
1100-H14 Aluminum Sheet

at the very top of the product selections, and,
at the aluminum sheet/plate page, 1100 is again at the very top of the product selections, and,
rivetboi's 0.125 sheet which I originally was referring to is second-to-thickest of the .032-.19 offerings, and is available in several sizes (or custom size), and,
without doing much math, all of their 1100 sheet appears to be cheaper than McMaster-Carr's 1100 products, which go up to 3/8".

And it's been that way since I visited there on 9/22 or 9/23.
And UPS says my package got in town this afternoon.
And my credit card has not yet been billed.

watson.fawkes - 6-10-2012 at 06:11

I made an honest mistake about OnlineMetals.com stock based on inconsistent information on their very own web site.

S.C. Wack first calls me a liar:
Quote: Originally posted by S.C. Wack  
[...] without "a credible person" saying simple, obvious lies in response.
And then claims I'm covering up after the fact:
Quote: Originally posted by S.C. Wack  
Anyone else would not be looking for supportive quotes
The lack of good faith that S.C. Wack exhibits in this interchange is abhorrent to me. In my second post, I quoted the page upon which I had based my original claim, which I am quite certain was my source, because I pulled from my browser history. Whatever, I suppose, makes him feel better.

Aluminum Wire

cal - 7-10-2012 at 03:28

Quote: Originally posted by bbartlog  
If you need high purity Al then aluminum electrical wiring is a good bet. Has to be high purity in order to have an acceptable electrical conductivity.


This is correct and some number 4/0 triplex is about 15 dollars for 5 feet. I use this all the time with great results.

[Edited on 7-10-2012 by cal]

Eliteforum - 7-10-2012 at 05:10

Fuck sake, if you need it that bad. Mail me.

Oscilllator - 8-10-2012 at 00:49

"Australian metal powders" is where I get mine from, and although their website doesn't say that they do postage they do. it's $12AUD but I dont know if they ship overseas. Also I think its about $18AUD/kg.

S.C. Wack - 8-10-2012 at 15:20

Quote: Originally posted by watson.fawkes  
The lack of good faith that S.C. Wack exhibits in this interchange is abhorrent to me. In my second post, I quoted the page upon which I had based my original claim, which I am quite certain was my source, because I pulled from my browser history. Whatever, I suppose, makes him feel better.


Translation: alleged repeated due diligence failure can't be characterized negatively by lesser beings; tongue the hole of the bullshitters, rather than be alarmed by unending bullshit.

Bend over and wait, then.

If anyone not looking for cheap unalloyed aluminium does buy nonexistent 1100 from onlinemetals, instead of unwanted rivets from ebay or something, do look closely for plastic film to peel off before using it.