Why the Trash You Sort Isn't Getting Recycled

http://www.americanoutlook.org ^ | December 29, 2003 | Dennis T. Avery

[Grampa Dave]

Maybe I should get a bag and put it in the back of my Bronco to neutralize the aroma coming from my fly fishing waders, belts and boots.

[E Rocc]

By recycling, did you mean that they actually melted the cans down to ingots? If so, what kind and size of crucibles did they do the melt in? And how long did those crucibles last, before needing replacement?

I ask because a dirty little secret of aluminum recycling is that the ratio of aluminum oxide to aluminum is at its highest in the thin sheets used to make aluminum cans. The aluminum oxide is a very good insulator and this causes hotspots in the crucible which results in overheating it to destructive levels. Crucibles are very expensive and the need for frequent replacement can destroy the cost savings of recycling.

Any comment?

We didn't do a lot of UBC (used beverage can) recycling because they got sloppy and because there's a lot of magnesium in them and we mostly made low-mag alloys.

You're right about the oxide content. Indeed, any metallic surface will have a thin coat of oxide on it. Fortunately, in some metals the coating is durable, thin, and continuous and further oxidation takes place slowly if at all. Aluminum is one of them.

Oxide is easy to deal with. Most of it floats, and can be skimmed off the metal bath once you separate it from the metal. There's several ways of doing this. One of the more popular is chlorine gas, which also removes magnesium.

If the oxide is left in the metal, it eventually forms corundum, which is like silicon carbide only harder, and sinks. That will clinton up a furnace worse than hot spots, though hot spots are one of the reasons that iron pots aren't usually used to recycle aluminum.

We used large reverbatory furnaces, up to 150,000 pounds capacity. A lot of stuff we'd crush and dry first. Not because of the oxide, but because of moisture. While the effect is more pronounced with magnesium (see the thread I just posted), moisture will also make aluminum explode.

Recycling isn't the cleanest industrial process out there. One irony about that is that when the Toxic Releases Reporting law first got implemented, the big "polluters" were the aluminum melters that were landfilling aluminum oxide byproduct. 8% of the Earth's crust is aluminum oxide, but since one rare form can be toxic, the EPA called all forms toxic. They de-listed it a year or two later, causing much whining among the greenies who didn't want anything delisted.

-Eric

[Grampa Dave]

That description sounds like the Redneck Voters that Howie the Metro Sexual Dean is after in 2004.

[Boot Hill]

"He is called the Garbage Nazi even by those on his staff, and...a few more colorful adjectives"

He's a doctor and should know better, being anal retentive is simply not a good recycling practice! Maybe a visit to the clinic's proctologist could help him.

--Boot Hill

[Lando Lincoln]

BTTT

Lando

[American_Centurion]

Plastic bottles are used because the shipping weight on them is about 1/10 that of the glass bottles.

BTW next time you feel bad about throwing away plastic, remember that it is a refined byproduct of petroleum refinement. I don't know what they did with the chemicals for polyethylene before bottles and bags, but I'm pretty sure that they weren't locked up as safely as they are in the polymer.

[Boot Hill]

Eric,

That was a really informative reply, thanks! I would have really enjoyed a tour of that place.

"(see the thread I just posted)"

???

--Boot

[Grampa Dave]

I think that the building has offered a free trip to the GI doc across the street for the Garbage Nazi. He just gets more determined and has even less humor than before.

[Boot Hill]

Dave,

"He just gets more determined and has even less humor than before."

After heart and brain activity, these are the three most important vital signs of life:

1. The ability to laugh.
2. The ability to learn.
3. A sense of adventure.

Doc seems to be missing the first two. I predict a short unhappy life for him.

--Boot

[Grampa Dave]

He has a deficit on all 3 vital signs you posted. #1, the lack of sense of humor is the most pronounced.

[stands2reason]

Welcome to FR, TWS!

[Diddle E. Squat]

[freedumb2003]

leakage from modern America’s landfills can be expected to cause one cancer-related death over the next 50 years.

I can't believe this whole thread has missed this critical and all-important point! Landfills are killers! They will kill someone in the next 50 years! What if it is YOU? Or your Mother! Or your sister? Or your infant child?? Or some disabled kid? Or some underpriviledged person of color?? Landfills must be stopped before they kill anyone!! We have to do something with all this garbage!!!!!

This is Bush's fault! He has killed with his lies and now he will kill with his trash! He MUST be stopped! How can all of you sit here compacently while this travesty goes on!! What is wrong with you!!!

</Dean rant>

[Triple Word Score]

Adding that to my repertoire of strategies. My garden battle may be futile no matter what I do. A maple tree wants my garden space. It keeps sending roots in, and branches to shade my raised beds. The maple tree is lovely and the jewel of my backyard, utterly necessary in July and August, but apparently there isn't a food crop in the world that likes maple roots tangling their way into their space.

[Amelia]

Look, we've been separating all that stuff for nothing!

[stylin_geek]

Hey, you know that Gore's son was picked up for marijuana possession, right? It's Bush's fault, because his tax cuts left more money in Gore's pocket, thereby enabling him to afford to buy an illegal substance. And, since smoke from marijuana is a known carcinogen, and also contributes to pollution, again, the environment is at risk...because of Bush's tax policies.

[alnick]

You can find much more detail at the gardenweb.com forums, specifically the soil forum.

[Triple Word Score]

Thank you!

[tubebender]

The rest of the recycles are thrown in the same truck. They extract the botttles and cans and compact the rest and send it to Utah, I believe.

This is a hoot GD. We ship our garbage to a land fill near you. It was supposed to go to Oregon. You know how much useless land in Humboldt County but they couldn't find a gulch to dump it in.

When they closed the landfill they turned 43 bear loose on Eureka. The garbage co had to change from night pickups to morning so people could put their cans out then to keep the bears form raiding them...