8
Scrap metals are not cleaned, they are melted. For steel; Zn, Sn, Pb, and others vaporize or oxidize. The most problematic is Zn as the oxide in the slag can deteriorate the refractory. Aluminum is similar except scrap aluminum containing Cu and Si will be segregated as much as possible, used for certain alloys. Copper scrap, being more valuable is separated ...
7
A quick look doesn't show a clearcut weight difference. The claim is more for a 'rounder' wheel and a 'stiffer wheel'
First order approximation fuel economy depends on the weight of the vehicle, given the same engine. Suppose that your vehicle weighs 1 metric ton -- 1000 kg -- 2200 lbs.
Suppose that an alloy wheel was 5 kg lighter. That would be 20 ...
6
Oh, that's really not a problem.
Recycling metal involves pre-processing. They are concerned with contaminants like paint and plating getting into the batch. What they use to remove paint and galvanization will certainly remove grease.
5
The old rails are certainly reused frequently here in the UK - they start off being used on high-speed lines. When they're too worn for that they get reused on low-speed lines, and then again on rarely-used sidings (spurs in US parlance).
Once they're too worn to be used as rails at all, they get reused for other things - e.g. fence posts and supports for ...
5
I am not an expert on mining, but I do know my way on fossil fuel extraction. Getting oil from the earth and making it into fuel is not as easy as it sounds, and really the process is way more contaminant than extracting metals from the ground.
To make it more clear I can try to explain it in parallel, in both you extract the resource from the ground, ...
5
Your friend is wrong and here's why.
Lithium is mined once and can be reused in any number of vehicles. When the vehicle breaks, its lithium will replace newly mined lithium. If we need let's say 2 billion cars on the road with batteries, they need a certain fixed amount of lithium. If we need 2 billion oil-burning cars on the road, they will continuously ...
4
Availability in the long term
You didn't include in your list a mention of how available copper will be in the future; this matters, for sustainability, because we can't afford to be using it for guttering if we're about to run out of copper ore. It is a very important metal for other purposes, such as electrical components.
Wikipedia has a good article on ...
3
Theory
The calculation in the other answer is rather naive. I haven't done the calculation myself, but there are a few things to consider. First of all, lighter wheels mean more than just lower overall vehicle weight. Advantages are:
lower overall vehicle weight: lower inertia of the car
lower weight of the wheel (rotating part): lower rotational inertia
(...
3
You can advocate for a carbon tax. When fossil fuel energy costs more, recycling is more economically valuable. Cheap power means easier to mine new aluminum. We really need a carbon tax for many reasons. They used to make a zillion tons of aluminum in the United States Pacific Northwest with dirt-cheap hydro power. But when electricity got expensive in ...
3
You (probably) cannot do it on demand side.
The reason this is impossible is that 99% of aluminum users don't care if their aluminum comes from recycled sources.
Let's say there's need for 100 units of aluminum, out of which 50 units are new, and 50 units are recycled.
Now, you introduce one unit of aluminum consumption, with the requirement that it comes ...
3
You've raised a few issues in your posts, so having just built a new house I'll address those I'm able to:
To start with, I live in a country/area where corrugated steel roofing is the absolute norm and has been for over half a century. In my town less than 1% of roofs are clad in anything else. Everyone collects rainwater. Everyone uses that rainwater. ...
3
1. Reuse
There are several websites describing ways to reuse aluminium cans, for example this page on WikiHow.com or this one on Earth911.com. Most common is to reuse them as a holder of some sorts (e.g. a pencil holder or candle holder), as earrings or as coasters. But I guess there a only so many pencil or candle holders and coasters you can use, so I ...
2
Metal production compared to population
Our World in Data provides statistics on global annual primary production of metals:
They also provide population data over the same time period. If we combine the two data sets, we can see the global per capita metal production:
To answer your question about the last 30 years or so; the data shows that metal ...
2
Wheel price is low
If you buy for fuel economy, then scuffed wheels from a scrapyard search service or classified ads are OK.
"$600 for a set of alloy wheels. Given the costs I saw at Tiretown ... prices were over that per wheel, let alone per set"
Ebay here in the UK has a good way of narrowing-down a quick search. I found one seller charging the same ...
2
Forget the foil. Even if you laminate it, you'll never eliminate tiny air gaps, which will make it into a fairly effective insulator.
I've seen (copper) heatsinks made from thin precision-cut fins, soldered to a thicker spreader plate. Solder is better than thermal epoxy, but doesn't work on aluminium. This was necessary for a specific purpose, but not ...
2
100% of all railroad steel is recycled... Eventually
On the active railroads (which you should not be walking on, by the way), you're seeing evidence of recent maintenance-of-way.
It is SOP in the rail business to pre-position supplies weeks or months in advance, and then take up to a year to pick up the old scrap. That is because of MoW priorities - ...
2
You are too late. A great tonnage of rail has already been used in the US. There is not "much" left in terms of serious usage. RR rails are hard, that is to say, they have a relatively high carbon content, so they can't be made into just anything.
Concrete rebar WAS a perfect match for old rails, so essentially all old rail became rebar. Rebar is ...
1
Contrary to the common mantra of "reduce, reuse, recycle", aluminium is best recycled instead of reused in a household setting. The reason for this is that demand for aluminium currently far outstrips the available quantity in the market, even at theoretically a 100% recycling rate. Thus, repurposing aluminium cans for things such as pen holders actually ...
1
First, it's pretty easy to remove sugary contaminants from the can right after you drain it. Everything is still wet, and you can just use dilution homeopathy style. If water is an issue in your area,
get all the liquid out as best you can e.g. By shaking in sink
add just an ounce or so of water
cover the hole with your thumb and shake
repeat
I am not a ...
1
You should do like all the commercial reverse vending machines do: crush the aluminum, don't melt it. The other answer already has one example way of crushing aluminum. If that doesn't work, well, try to find some other way instead of considering melting.
Another way of crushing is to put the can on its side: it's less strong when placed that way, and the ...
1
As it turns there are several solutions. And as I've discovered, the headline is: aluminum is probably fine. HOWEVER ... in my case I think it will be cost-prohibitive, since a 4x8 sheet costs ~$100.
I found the documents that @Dispenser referred to, and luckily, they were commissioned by the Texas Water Development Board.
TWDB Document 1
TWDB Document 2
...
1
Copper for such a use could potentially be a health risk to those succeptable to things like hepatolenticular degeneration. This depends on how much copper is already present in the soil, what type of well is being used, whether the water is being treated before consumption, and many other factors. Sustainable though? Might depend on what the chemical makeup ...
1
What are the most promising alternatives, in terms of the economics and scalability, to decarbonise steel production? Both for the reduction of iron oxide to iron, and for the iron-to-steel process?
I'll answer the first:
Direct reduction of iron oxide to iron using hydrogen.
There are several features that make this a promising alternative:
Firstly, ...
1
Are you talking in terms of use and disposal per person, or life cycle of metal?
The difference being are you interested in how much metal a person consumes and disposes of? Or how much metal gets to land fill and averaging that out over the population?
Not all metal disposed of will make it to land fill.
I suspect you're question is the first (disposal ...
1
There are a lot of factors and different ways to view environmental impact and it depends on your priorities. If you prioritize energy used to produce, assuming Nate's citation is correct, the steel is only good when the energy required to produce (mine, refine, smelt, forge, transport, etc.) is less than the energy used to produce an equivalent amount of ...
Only top voted, non community-wiki answers of a minimum length are eligible