# PM from CD or CD-R?



## TommyBerlin70

Has anyone ever cd's or cd-r's or similar recycled?
I found nothing with the Forum search.
I found an article at the web about this sorry it's in german but maybe google translation service helps a little bit.
http://www.ruhr-uni-bochum.de/rubin/rbin2_01/studieren/index.html

I find this interesting because old cd's are available everywhere.

Best Regards
Tommy

edit: According to report are 10 mg of silver or 9 mg of gold per cd included depending on the type.


----------



## MMFJ

While there are a few CDs that have a low-grade optic diode 'eye' that is gold plated, that is the only 'easy' bits that are available, typically. One video I did on this is [youtube]http://www.youtube.com/watch?v=7pbJD2rSniw[/youtube]

Everything else (whatever that may be in total, I have no data) is in the components on the boards and perhaps a bit on the pins.

The reason you don't find a lot of data on this forum (though there is some, this topic has been discussed many times) is that there really isn't enough to mess with for a backyard refiner - either because of the cost to recover, the waste of chemicals, dangers, etc. (again, discussed on the forum at length as to the 'reasons' why not everything that has PMs is worth recovering yourself - many times it is best to just "get the fast penny, not the last penny").

Best to sell the boards to an accumulator, that will then sell off to a refiner. There are many on this board that buy the cards from the CDs, hard drives, etc., the rest is just metal scrap, which is also not heavily discussed on this forum.


----------



## patnor1011

There may be something valuable on certain types. They are being recycled or collected in recycling centers however you will spend thousands of dollars trying to get hundreds of dollars if you attempt to do it yourself.
I would say that if buyers do not pay for them, we cant make money out of them. I would look up for what they do want to buy, then I will know what to look for and CD or DVD disks are not one of that things.


----------



## Intihoa

Hi all

I'm interested in CDs too (not CD DRIVES!!) I know it contains silver; DVDs contains gold and/or silver but how much i dont know..
Silver and gold are used in optic discs as a reflective layer (like in mirrors we use silver paint)
Some Discs uses aluminum though.. 
I actually etched the printable layer and the lacker of a CD ROM with Sodium hydroxide + hot water.. i was very exited seeing the "silver" layer exposed so easily..
It wasn't aluminum as it haven't reacted with NaOH.. 

I'm still a novice (just registered today) so if anyone can reproduce what i did and confirm its really silver, please tell us.. I would be glad if someone could also volunteers to make a test on the yield as i dont have the skills yet to do that myself..


----------



## NoIdea

Hi All - just a thought, what if one takes a CD cleaner, change the polishing disc's to course sand paper and grind off the layers in question, probably work on HD platters to.

Deano


----------



## modtheworld44

NoIdea said:


> Hi All - just a thought, what if one takes a CD cleaner, change the polishing disc's to course sand paper and grind off the layers in question, probably work on HD platters to.
> 
> Deano



Noidea

My GEOMOD cell can strip a hd platter in about 3-5 minutes.



modtheworld44


----------



## Pikachu2000

You'll likely find the metal layer in a CD is aluminum, not silver.


----------



## Intihoa

I m not an expert in chemistry but i know that aluminum will dissolve in Sodium hydroxide (NaOH) so I'm sure the metallic layer i exposed is not aluminum, since it didn't dissolved
But i can't say it is silver, either ..

Disc i tested is a Verbatim 52x CD-R


----------



## butcher

hard drive disk, mostly a cobalt alloy carbon based overcoat and a lubricant on aluminum or glass disk coated using vacuum desposition or sputtering, very little platinum is included is some disks but not enough to be able to recover it economically, others can have High iron based material


----------



## Intihoa

Thanks butcher that was a very informative post about hard drive discs; i always wondered if it was profitable to recycle those ones..

Here is my little research on CD DVD discs:

CD-ROMs/DVD-ROMs
Commercial grade: aluminium is most frequently used 
Archival grade: silver or gold(longer life expectancies ,better reflectivity)

CD-Rs/DVD-Rs (recordable) 
Silver, silver alloys and gold (Aluminium is not used because it may react with the dyes used as storage layer)

CD-RW/DVD-RWs (rewritable) 
Usually use Aluminium reflective layers, because the storage layer (phase changing film) degrades faster than aluminium


----------



## butcher

The links did not work.

How much does each CD cost, how much does it cost to make one, they are made to store data Music and so on, how much did research and development of the product cost, how much does it cost to get them to the buyer, and so on, can they put much high priced metal in it and still sell it for a profit, many things may contain gold silver or some other metal, I have not seen the links you are talking about, but I have heard the had CD disk that had gold in them, but with modern technology and sputtering or other techniques they can make things using very little of these metals, lets say for the sake of argument they used 3 cents worth of gold, and it cost you 10 cents worth of fuel and 10 cents worth of acid, and two days work to recover the gold, then you have cost of refining, and melting....

The question is first does it have the metal, how much; can you recover and then refine it at a profit?

Many rocks can contain gold, heck some mountains are just plum full of it, but a miner may make more money breaking that mountain down to gravel and selling the gravel than he could ever make from mining the gold out of that rock.


----------



## MMFJ

butcher said:


> Many rocks can contain gold, heck some mountains are just plum full of it, but a miner may make more money breaking that mountain down to gravel and selling the gravel than he could ever make from mining the gold out of that rock.


I went to look at some property on the ocean here in Ecuador - beautiful place - and the land is 'full of gold' (according to the current owner and various testimonies from locals, etc. - no assays, etc.).

From what I understand, much of the land here does contain various amounts of gold and some places are well worth working.

HOWEVER, there is one little 'gotcha' that stops folks around here - the government says that any gold taken from any land is THEIRS and you must turn it in or face huge penalties, etc.! Oh, you might get by with a tiny sluice box in a barn or something, but to get any serious payback you would need an operation big enough that would very (very) likely be spotted.

So, there's just one more something to watch out for in your quest for "gold, at any price".

The question is not "is there gold in there", it is (and always should be, IMHO) "is it worth the work and effort?" - I hate as much as anyone to know I'm tossing away pennies, but when you know it costs dollars to get them, something just isn't right! 

One story though, about 20 years ago I was tasked to toss the "old" computers from our company when they were upgrading - we must have put 300, 386/486 right into the dumpsters. funny thing is, I recall clearly telling my boss that there was gold in them but we both agreed that it wasn't worth the work and effort...... - wasn't then, but would have been worth holding on to them, had we had the vision..., - so, just where is that 'line'?


----------



## Intihoa

(Sorry butcher those are underlined titles not links)

If you want the source of the info here it is http://en.wikipedia.org/wiki/Optical_media_preservation#Optical_disc_types..
You are wright about the profitability question you asked.. but i think better we test than make simple suppositions.. thats why i posted in the first place..
CD-Rs are widely available if there was 3 cents profit in each one and i can process thousands of them maybe it will cover all my expenses and make me a good margin of profit..
So like i said it's subject to testing..
If anyone had made the test please tell us..
or if anyone feel it can do it please go ahead and keep us informed

If my sources are correct, only CD-Rs and DVD-Rs uses exclusively PMs, so if someone want to test, do with this type of discs..
Hints: 
Sodium Hydroxide + Hot Water will expose the metallic layer in no time 
I think Nitric acid or aqua regia will then dissolve the silver or gold exposed

(i think Multi layer discs processing will be different as the architecture of the layers is different)


----------



## patnor1011

If you can do it with profit you deserve Nobel prize for science. You have to try it to really find out if you cant hear from people who know what they talk about. Enough said.


----------



## Intihoa

I'll quote from my previous post:


> If anyone had made the test please tell us..



Thank you. 

Enough said. :mrgreen:


----------



## butcher

From the link you referenced:

CD-Rs/DVD-Rs (recordable) are recordable, write-once discs, which use photosensitive organic dye just below the reflective layer; the dye undergoes a chemical change when exposed to specific laser light beams, DVDs. Both gold and silver will outlast the organic dyes, which will decay over time. Aluminum is not used because it may cause reactions with the dyes.
The data layer, supported by the polycarbonate substrate can be metallic or dye-based, depending on the disc type
The reflective and data layers of CDs are just below the label and a thin sheet of polycarbonate substrate. A much thicker layer of the substrate supports and protects the bottom of the disc. The reflective and data layers of DVDs are in the center of the disc structure, housed between two equal layers of polycarbonate substrate. Because the data layer of CDs is more exposed than DVDs, a thin metal lacquer layer is used to protect the surface of the CD. The top of a CD is delicate and fragile; the bottom is merely a transparent protective covering.[2]
For preservation purposes: Gold CD-R (Compatible Disc-Recordable) and DVD-R (Digital Video Disc-Recordable or Digital Versatile Disc-Recordable) discs are preferred by experts over aluminum and silver for reliable long-term backup storage—the reflective layer of the optical disc is gold.
-----------------------------------------------------------------------------------
Ok no doubt some do have gold and silver Question is it worth it to process.
Only way to know is to try and prove it to yourself.
Now you need could set up a furnace complete with after burner chambers, a scrubber, and bag filters, collect a few thousand of these disks, and burn them, sift through the ashes and see if you could find a tiny button of gold.

Some reason I cannot see enough gold in the dye to be worth messing with, for me anyway.
I would not waste my time trying to find out.
That is just my opinion.
Enough said


----------



## VanMarco

I have several hundreds of dvd-r, i will definetely give it a try, So I should just prepare a hot solution of NaOH and put the dvds In til the surface is dissolved?
I'll do that for the forum


----------



## resabed01

VanMarco said:


> I have several hundreds of dvd-r, i will definetely give it a try, So I should just prepare a hot solution of NaOH and put the dvds In til the surface is dissolved?
> I'll do that for the forum



What you propose to do will only work for CD-R and not DVD-R.

DVDs have a different construction from CDs. To open up a DVD-R you simply hard-flex the disc and the two layers will seperate opening up the recording layers.


----------



## joem

patnor1011 said:


> If you can do it with profit you deserve Nobel prize for science. You have to try it to really find out if you cant hear from people who know what they talk about. Enough said.



Current activities lean towards a profit in these because my metal recycler pays by the pound. Somebody must be making money on the metals within.


----------



## Captobvious

joem said:


> patnor1011 said:
> 
> 
> 
> If you can do it with profit you deserve Nobel prize for science. You have to try it to really find out if you cant hear from people who know what they talk about. Enough said.
> 
> 
> 
> 
> Current activities lean towards a profit in these because my metal recycler pays by the pound. Somebody must be making money on the metals within.
Click to expand...


I'm thinking there's some confusion going on in this thread, in one post you have CDR (drives) being discussed and others you have CDR (discs) being discussed. I believe Patnor was responding to the idea of profiting off the discs, not the drives themselves.


----------



## joem

I was talking about CD discs not the drives


----------



## GotTheBug

I actually just played with this recently. Had a few of the premium discs with a bit of gold and over 100 "regular" cd's, cd-r, some installation, etc.

The gold was, indeed, gold, though not much.
The regular cd's, and this was funny, were obviously aluminum.

I used a razor blade to just lightly score the coating approximately every 3/4 inch around the disc, then dropped them into some HCl, which made short work of separation.

The gold ones separated nicely and left a bit of gold "dust" in the bottom of a mess of "coating flakes". Again, not much, but it's there.

The aluminum obviously completely disintegrated, leaving the same "coating flakes", the polycarbonate discs themselves, and a light brownish colored HCl. Again, not worth the effort, but it was a learning experience.

Hope this helps.


----------



## rickbb

I used to work in a manufacturing plant that made CD's, (not CDR's). The metal coating is Al and is appx 50 microns thick. Its vapor deposited in a high vacuum chamber, then coated in lacquer. We did do some gold CD's, not many, and it was 24ct but still only 50 microns thick.

DVD's usually are coated in silicon as the reflective coating as that will reflect the blue/uv laser in the player better.

But again the reflective coatings are vapor deposited in microscopically small amounts. There only needs to be 70% reflectivity for the disc to play correctly.

I would think getting all the lacquer and polycarbonate separated would be really hard, and then you have plastic waste to get rid of.


----------



## FrugalRefiner

rickbb said:


> I used to work in a manufacturing plant that made CD's, (not CDR's). The metal coating is Al and is appx 50 microns thick. Its vapor deposited in a high vacuum chamber, then coated in lacquer. We did do some gold CD's, not many, and it was 24ct but still only 50 microns thick.


That sounds awfully thick! Might it have been 50 microinches instead of 50 microns? Fingers, pins, and other contact surfaces are often estimated at 30 microinches thick. 1 micron equals 39.37 microinches. You're saying the coating on a CD is 65 times thicker than that on fingers.

Dave


----------



## Claudie

The 39th item down the list on this site:

http://www.computerplatinen.de/elektronik-recycling-preise/schrott-computer-platinen.php

That sounds like a pretty good buy price so they must be worth something.


----------



## rickbb

FrugalRefiner said:


> rickbb said:
> 
> 
> 
> I used to work in a manufacturing plant that made CD's, (not CDR's). The metal coating is Al and is appx 50 microns thick. Its vapor deposited in a high vacuum chamber, then coated in lacquer. We did do some gold CD's, not many, and it was 24ct but still only 50 microns thick.
> 
> 
> 
> That sounds awfully thick! Might it have been 50 microinches instead of 50 microns? Fingers, pins, and other contact surfaces are often estimated at 30 microinches thick. 1 micron equals 39.37 microinches. You're saying the coating on a CD is 65 times thicker than that on fingers.
> 
> Dave
Click to expand...



You are correct, I'm getting my micros, angstroms and nanos mixed up, and we actually measured it in its reflective value not an actual thickness. Above 70% pass, below it was scrap.

It's thin enough to see through when you hold it up to light in front of your eye. The deposit stage only takes 0.2 seconds on the production line so it's not much there even if it were gold. We made a complete CD ready for silk screen printing in 2.6 seconds total.


----------



## rickbb

Claudie said:


> The 39th item down the list on this site:
> 
> http://www.computerplatinen.de/elektronik-recycling-preise/schrott-computer-platinen.php
> 
> That sounds like a pretty good buy price so they must be worth something.




They could be buying them for the optical grade polycarbonate plastic and not the metals, that’s what we sold our scrap for back in the day. I don't think the price of scrap aluminum is that high to try and get it off a CD. But who knows stranger things have happened.


----------



## solar_plasma

At 100nm thickness it would take only 100 dvd-r with gold layer to yield about 2g gold, if my math is corect. Has anybody found out, if all gold coloured dvd-r's actually contain gold?


----------



## necromancer

solar_plasma said:


> At 100nm thickness it would take only 100 dvd-r with gold layer to yield about 2g gold, if my math is correct. Has anybody found out, if all gold coloured dvd-r's actually contain gold?



current price i am getting now is $0.16 per pound, i think that is better & faster + less waste.

what are most people doing with there left over parts ?


----------



## Sharding757

Found this on metal mine media while searching on the validity of it all: I don't know if what is claimed here to be true, but figured I'd offer it up for others to see.

http://www.metalminemedia.com/2013/03/presence-of-gold-in-cds-dvds.html

//I copied and pasted the content to avoid having to go to the site to read and possible spam//

Presence of Gold in CD’s & DVD’s
Thursday, January 31, 2013 2 comments

With a CD having a diameter of 12 cm, and the inner non-writable part having a diameter of 4 cm, we get a total writable area of around 100 cm². I read somewhere that the different densities of the “gold, silver, aluminum” layer are between 20 to 100 nanometers (billionths of a meter). Assuming the worst case scenario, 100 nanos, we get a total gold volume of 0.00001 cm³. At a gold density of about 19.5 g/cm³ this volume equals 0.000195 g. With one troy ounce equal to 31.1 g., this weight of gold equals 0.00000627 troy oz., or rather, one troy ounce of gold is good for 160,000 CD-Rs. At a gold price of U$S 450 per troy ounce, there is U$S 0.0028 gold per CD-R, or 0.28 cents worth of gold. Of course, the density of the gold layer could be as low as 20 nanometers. In that case, the gold content in the CD would be worth 0.06 cents, and one ounce of gold would be good for 800,000 CD-Rs. So there you have it.

One final step. 10 billion writable CDs are sold every year (versus 20 billion audio CDs). The gold/silver CDs are phthalocyanine, and I read this type of CD is second in market share. So let's give the gold/silver CDs a 25% market share. Now let's assume the gold variety is about half of that, so the total gold CD market share is about 12%, or 1.2 billion CDs annually. With one ounce of gold good for 160,000-800,000 CDs, we need a block of gold every year that is from 2,400 to 12,000 cm³ or a cube with each side being 13 to 23 cm long (5 to 9 inches). This block would weigh 100 to 500 pounds and be worth 700,000 to 3,400,000 dollars. So there you have it.


----------



## johnny309

In CD or DVD that are recordable(you can write them in your own computer)....they contain Ag.....12mg/piece to be precise.
So,in another words you will need 1000 pieces for 12 grams of silver. One disc weight 16 grams.
The commercial type (prerecorded) and the rewritable disc contain Al.


----------



## rickbb

This site has one of the best descriptions of what type of disc "may" contain silver or gold.

http://www.clir.org/pubs/reports/pub121/sec3.html


----------



## solar_plasma

Thank you, rickbb! If this info is complete, then all golden and green coloured (non-RW) types should contain some gold.


----------



## rickbb

solar_plasma said:


> Thank you, rickbb! If this info is complete, then all golden and green coloured (non-RW) types should contain some gold.




I would urge caution, as they "may" contain some PM's. When I was in the business we were just starting up a CD-R manufacturing line and we used AL, not silver. We ran the costing process on starting up a DVD-R line and the equipment we looked at used silicon on them, not gold.

Each supplier of the equipment had their own proprietary process for manufacture so there is a lot of variation in what is being produced.

We only sputtered gold on discs by special request and a serious up charge. A solid pure gold sputtering target was $20k in the mid 1990's. And boy was it sight to look at. It always gathered a crowd when the techs had to hang one in the line. Big gold doughnut!


----------



## meatheadmerlin

I stumbled onto a way to get at the layer of metal between the 2 layers of plastic in a DVD+R.

I had some difficulty writing one and took it into the back hall to snap it in half (in anger), like I sometimes do to CD-Rs that are problematic.

Well, it didn't snap. It bent in half instead, so I left it on the concrete floor there. The back hall is quite cold during winter, and when I returned there I tried to unbend it (for no good reason). It snapped in half then, and began peeling! The layers had separated where it was bent.

So, there may be hope to use mechanical stress then chilling to separate the layers. Perhaps bending the disc/disk into a curve, chilling, and then unbending would do the trick.


----------



## nickton

Huh? :shock:


----------



## Tquilha

I'm kinda raising this topic from the dead, but I just made my first experiments with e-waste, and it was just about this.
Getting the silver off old CDs and DVDs.
I can confirm that "pressed" CDs or DVDs have Al and no Ag. All advertising CDs and DVDs are the "pressed" type.
CD-R and DVD-R have Ag, but very little (very likely the 12 mg/piece mentioned here).
To process DVD-R all you need is a box cutter and some patience. Score along the rim of the DVD until the tip of the blade cuts into the disc. Then it's just a matter of slicing the two halves apart. Mind you fingers!
CD-Rs are different. They have a single layer of polycarbonate, then the silver layer and then a paper or plastic layer. All you have to do is score the paper layer with a cutter, so that the nitric acid can access the silver layer.
To dissolve the silver, all you need is to dunk the disc in dilute nitric acid. The reaction is quite fast. 
Rinse the clear discs with distilled water into a separate bucket, and recycle the polycarbonate. 
So far things look promising (for a 1st try) and I'll be cementing the silver with copper when I have enough solution.


----------



## rickbb

That metal layer is vacuum deposited and is appx 200 to 300 angstroms thick, which is 0.02 to 0.03 micrometers thick. 

That's for CD and CD-R, DVD and DVD-R variants have even thinner coating due to them being multi layer construction, and the laser needing to focus through the various layers. DVD 5 and 

Some math to calculate cubic area of the disk will tell you how many you will need to yield an ounce of metal.


----------



## anachronism

Waste of time unless you have tonnes and a process that's efficient.


----------



## rickbb

anachronism said:


> Waste of time unless you have tonnes and a process that's efficient.



AND assuming that the metal is actualy gold or silver, which most aren't.


----------

