Identifying materials

Partly out of curiosity I am breaking up some defunct appliances. I am wondering what (if anything) is to be gained by separating them into their component materials. However, I'm hitting some uncertainty about what some things are.

Steel is usually fairly easy to spot (it's usually rusty). Ally also, cos it weighs almost nowt.
But there are a few things have me stumped, and more valuable stuff like nickel, I wouldn't know where to start: apparently it is used a lot in heating elements, (apparently it's around £16,000/tonne, so it's worth looking for).

And then there are plastics...

When I was young ..elements where nickal cadmium alloy. I think that is the bug with most modern materials they are all alloys. Even what you call steel will be a mix. Copper and alluminium usually have a value worth selling if you have enough. Got a scrap merchant near you?

Zoe wrote:When I was young ..elements where nickel cadmium alloy.

I think you mean chromium.

Even what you call steel will be a mix.

Steel is by definition a mix. Usually carbon though.

Copper and alluminium usually have a value worth selling if you have enough. Got a scrap merchant near you?

There are metal yards everywhere. Not found where to cash in plastics yet though.

Yep you are right the on the element...sorry brain literally be working in other dimensions today...

The steel I beg to differ. Being involved in the structural engineering side of building a bit there are many many many different steel types.

Zoe wrote:The steel I beg to differ. Being involved in the structural engineering side of building a bit there are many many many different steel types.

Yes indeed, but all of them are a mix of iron and... The relevant point being that they are a mix.

Steels are an alloy of iron and a huge number of small traces of many other elements...most of which don't matter from a scrap point of view but a few do....and can mess up a scrap iron charge!

Much like Pyrex in a glass recycling charge will mess up the whole thing....

Compostwoman wrote:Steels are an alloy of iron and a huge number of small traces of many other elements...most of which don't matter from a scrap point of view but a few do....and can mess up a scrap iron charge!

So which do, and how do I spot them?
And what is this bit? I'm not at all convinced it is steel, but I don't see why it'd be anything else. :?

Hmmm tricky....

It does beg a bigger question doesn't it? Perhaps one day everything will be reusable, truly recyclable, compostable or ok to return to the earth (like brick)

Pretty well all steel is OK to melt down....it is really the specialist stuff, which probably wouldn't get into the waste stream...

But the Pyrex issue is serious...it really does mess up a whole recycling bin if it gets mixed in....

Well I have learnt something there
Pol

Compostwoman wrote:But the Pyrex issue is serious...it really does mess up a whole recycling bin if it gets mixed in....

I reckon I can probably just about distinguish between steel and pyrex... as long as I've got a handy magnet.

yes but would you be able too, in a load of broken glass cullet?

Compostwoman wrote:yes but would you be able too, in a load of broken glass cullet?

Let's sort out metal and plastic before we start fretting about amorphous silicates.

But...seriously...lots of folk CAN manage to recycle glass..they CAN sort it out into brown. green and clear...but IF they put a pyrex plate etc into the mix...it is buggered!

So more signage and more education is needed I think..

Not you HL! I know you know the difference.......

Compostwoman wrote:Not you HL! I know you know the difference.......

Yes, so can we get back to the point... I'd heard a rumour you were trained in metallurgy.

Yes.., many years ago now!

it is quite hard to identify plastics, if they don't have the obvious logo on the bottom (Moibius loop for recycling and the number code for different plastic)

I will look out the different symbols and post them up in here.

Steel - well as you say the magnet test...recycling MRF's use eddy current detectors to separate out "tin" cans from Alu....

I wouldn't worry too much about specialist alloys in steel....it is such small quantities and is unlikely to be mixed in to the general eveyday stuff...

Copper well old boilers, inner of elec cables , fairly easy to detect.

With glass, Pyrex tends to be plates, casseroles etc so should be obvious if its not a glass jar or bottle - so if you are looking at rubbish dumped glass . if its old windscreens it will be toughened glass, if its smashed wine bottles it will not..

Compostwoman wrote:it is quite hard to identify plastics...

I am not sure that it is. But you do have to have the knowings.

Steel - well as you say the magnet test...recycling MRF's use eddy current detectors to separate out "tin" cans from Alu....

Yes, I think I'd covered that earlier. What about the other stuff: nickel, tin, zinc, etc.
Presumably there isn't enough zinc in galvanised to worry about it.

Copper well old boilers...

No need to get personal.
What else might wire be made of? I had some yesterday (out of a cooker) that was a silvery colour: didn't look like copper at all. :?

With glass, Pyrex tends to be plates, casseroles etc so should be obvious if its not a glass jar or bottle - so if you are looking at rubbish dumped glass . if its old windscreens it will be toughened glass, if its smashed wine bottles it will not..

I don't believe there is any great saving in making glass out of glass rather than virgin material, so I have no qualms about putting uncertain glass into landfill.

One more thing. I read a while back that there is more gold per tonne in scrap electronics than there is in most types of gold ore... question is, how to extract it?

Gold plating on pcb's can be reverse electrolytically stripped off...but its not the sort of thing you do in a back workshop....

Metal detectors can separate out Nickel from Copper and its alloys. In fact a lot of separation can be done using magnets, as different metals have different magnetic properties..

I don't know HOW they do it in a scrap yard , tbh apart from magnets......I know how to identify different metals, (I know lots of other ways) but not many would be applicable in "ordinary" life....

And tbh I don't think, beyond a metal detector and a good eye, you would be able to, either...

Compostwoman wrote:Gold plating on pcb's can be reverse electrolytically stripped off...but its not the sort of thing you do in a back workshop....

Oh Ye of little faith.

And tbh I don't think, beyond a metal detector and a good eye, you would be able to, either...

There is, however some degree of knowing what is used for what: for example, the heating elements will likely contain a high proportion of nickel... whether or not it is worth the effort of separating them is another matter. :?

Perhaps I should have said "Gold plating on pcb's can be reverse electrolytically stripped off...but
its not the sort of thing you SHOULD BE DOING in a back workshop...."

Compostwoman wrote:Perhaps I should have said "Gold plating on pcb's can be reverse electrolytically stripped off...but
its not the sort of thing you SHOULD BE DOING in a back workshop...."

Perhaps you should, but if you had, I'd probably just have said, "Aww. Why not? Doesn't sound like rocket science."