Best way to sell my aluminum chips

[elsocal]

This is my first post, so please bear with me.
I'm new to making chips and would like to know the best way to sell aluminum.
I took a load to a recycler and they said it had steel mixed in and did not want it.
1. What is the best way to keep steel/alum. separate?
2. Solids are worth more than chips, Can I melt the chips into billets?
I have a Haas SL-20 and a VF2 with augers and mainly work with alum.
Any help with the above would be greatly appreciated.

[skullworks]

I comes down to work.

You need to do a complete interior washdown and clean out when switching materials. To be done right this can take a few hours. If you do short runs swapping materials often this may no be cost effective in the current scrap market.

For the hobby machinist that sometimes does high volume of chips a used trash compactor might work to make blocks of chips.

Big shops use a "Pucker" machine which shreds chips to break up drill chips and presses the "borings" into disks somewhat like a Hockey Puck. The process also removes 99% of the oil and the recyclers will pay near solid prices for "Pucked borings".

[Geof]

Unless you have a machine dedicated to aluminum which never touches steel it is almost certainly not worth the effort to try and recycle the aluminum chips. Any place you take them to is probably going to swipe a magnet through them and reject everything if even the smallest speck of steel shows up.

Melting them yourself is not practical unless you happen to own a foundry and puckers cost upwards of $50,000 and can handle several thousand pounds per hour so they are not practical for a small shop.

[kling8]

Every shop I have worked at recycles aluminum, The thing you have to do is clean all the steel out, vacuum, wipe down, what ever it takes to get all the steel out. So it takes some time if you go back and forth between alum. and steel, or what ever. Good job for the low man on the ladder.
Hope this helps good luck.

[elsocal]

Thank You all for your help.
I do have a natural gas furnace and thought of melting the chips. Has anyone tried to melt. the chips using a flux to separate the steel from the alum?

[tnik]

melting point for aluminum is over 1200 deg F, carbon steel is over 2600, so it might work. I would call around to the different scrap yards and find out exactly what is the best way to prepare the scrap is.

[skullworks]

The cost of fuel alone will exceed the price you will get for the metal.

Plus the wages to pay someone to do this, plus the increase in business and workers comp insurance when they find out you have added foundry operations.

Lastly you might find yourself in trouble with the city for Zoning violations.

[hmaki]

Hello from Finland!
This is also my first post.

You can use ECS or just a magnetic.
Also sink and float separation is good. In this case you have to change water density to 3.0kg/dm3, because aluminium density is 2,7kg/dm3.
You can use there ferrosilicon.
Now you can pick up floating aluminium and fe will be sink down to bottom.

Yeah... I am working in recycling company

[MadMax]

Aluminum oxidizes very readily. You wouldn't be able to smelt chips into good ingots without an inert gas shield.

My recycler seems to be happy to pick up my chips. I seem to get around 2% of recyling value (by mass) out of my chips vs. mill run bar stock which in my mind is pretty good. I do clean out my machines pretty well between material changeovers and I have a rinsing scheme to recover my coolant for my chips. Basically I wash my make up water over my daily chip accumulation before putting it into the coolant tank so I also rinse off the coolant stuck to the chips.

I keep most of my coolant and the recycler doesn't have to wash it off.

[Dynamech]

This idea is more for hobby CNC than a small shop setting.

How about magnetic separation? Harbor freight and others carry vibrator tumblers than you could load your aluminum chips into, toss in a stong rare earth magnet (maybe about an 1" cube in size?) and let it run for a while. If you have the space for more than one then you could set up a washing line moving from one tumbler to the next getting "cleaner" each time. One good strong magnet in each one should do it especially since more than one would just stick together.


http://www.harborfreight.com/cpi/cta...emnumber=93252

[HuFlungDung]

Originally Posted by hmaki Hello from Finland! This is also my first post. You can use ECS or just a magnetic. Also sink and float separation is good. In this case you have to change water density to 3.0kg/dm3, because aluminium density is 2,7kg/dm3. You can use there ferrosilicon. Now you can pick up floating aluminium and fe will be sink down to bottom. Yeah... I am working in recycling company

So if it is that easy, then the typical scrapyard is ripping off the typical shop with their iron contamination penalty for bringing in slightly contaminated aluminum. That sounds about par for the course!

When I look at these automobiles being shredded, mashing virtually everything together to be seperated again later, I have to think that any aluminum recycler is going to have a good system in place to handle slightly contaminated aluminum scrap.

If oxidation of finely divided scrap is a real issue, then why are aluminum drink cans supposedly a good feedstock? Even crushing the chips into a puck does not alter the surface area that has already suffered room temperature oxidation.

Surely, starting with aluminum chips has to make more sense than starting with bauxite?

Is electrolysis out of the question for chip recycling?

[MadMax]

You'll get very fast oxidation if you melt the stuff. Aluminum really really likes oxygen, but room temp oxidation isn't anything close to what you'd see at molten temps. Even a high surface area pop can still has a majority of unoxidized aluminum atoms.

I would guess that aluminum recycling is done in an induction furnace with an inert shield.

Aluminum is already electrolytically refined from bauxite ore. Unfortunately it has to be done at high temp with a flux electrolyte because everything has to be liquid for you to move ions around.

I would think that chips would be separated with a magnetic drum to start things off. Automotive recycling is full of steel and aluminum. I can't believe that a small contamination of steel could be a very big deal. I would think that coolant or tramp oil fouling is a more frustrating issue because it would cause the aluminum to adhere to a magnetic drum.

Hmaki, how would you increase the density of water? There aren't very many dense liquids out there. I can't imagine how float separation would work for metals. You can remove plastics from metals with float separation, but I can't see separating aluminum from steel easily.