Circuit/computer board components?

[CFirehawk]

I'm trying to identify everything in a PC worth salvaging. I've heard of grinding up chips, but, which ones? Do all the black chips on a board have internal value? Just processing units? Do any of the capacitors or resistors have anything worth smashing away to? I currently even clip the copper parts out of the power supply to get all the PM/semi-PM I can. And the case and body are scrap steel, right? I guess I'm looking for: How to eat a PC as thoroughly as possible.

 

[badastro]

Aluminum electrolytic capacitors contain no precious metals at all. You'll find that they are mostly aluminum with copper leads, but they are not worth much if at all. Larger ones are considered hazardous waste because of glycol and other electrolyte contents.

 

[aflacglobal]

TABLE 1: Substances Found in a Desktop Computer
(Based on a desktop computer weighing 70 lbs.)
NAME % TOTAL WEIGHT USE/LOCATION

plastics 22.9907 housing
lead 6.2988 CRT, metal joining
aluminium 14.1723 conductivity/housing,CRT
germanium 0.0016 semiconductor, ckt board
gallium 0.0013 semiconductor, ckt board
iron 20.4712 magnetivity/(steel) housing,CRT
tin 1.0078 metal joining, CRT
copper 6.9287 CRT, conductivity, connectors
barium 0.0315 CRT, getter in vacuum tube
nickel 0.8503 magnetivity/(steel) housing,CRT
zinc 2.2046 battery, phosphor emitter, CRT
tantalum 0.0157 capacitors, power supply
indium 0.0016 transistor, rectifiers
vanadium 0.0002 CRT
beryllium 0.0157 ckt board, connectors
gold 0.0016 connectivity, conductivity
europium 0.0002 ckt board
titanium 0.0157 housing
ruthenium 0.0016 ckt board
cobalt 0.0157 CRT, ckt board
manganese 0.0315 CRT, ckt board
silver 0.0189 ckt board
antimony 0.0094 CRT, ckt board
bismuth 0.0063 ckt board
chromium 0.0063 housing
cadmium 0.0094 CRT, ckt board, battery
selenium 0.0016 ckt board
niobium 0.0002 housing
yttrium 0.0002 CRT
mercury 0.0022 ckt board, batteries, housing
arsenic 0.0013 ckt board
silica 24.8803 glass, CRT, ckt board

 

[lazersteve]

Here's the exploded view of a Slot 1 pc with the various parts labeled:

[img:748:816]http://www.goldrecovery.us/images/pc_exploded_labels.jpg[/img]

And a quick listing of metals for each item:

• Case= Galvanized Steel
• Power Supply
  1. Housing =Galvanized Steel
  2. PCB=Various Metals in Components: Tantalum, Silver, Tin, Copper, Aluminum, Gold, Palladium, Nickel, Ruthenium, Lead, Silicon
• Front Cover= Plastic
• Motherboard, PCI Card, Floppy Drive, CdRom, Hard Drive, Memory Stick=Various Metals in Components: Tantalum, Silver, Tin, Copper, Aluminum, Gold, Palladium, Nickel, Ruthenium, Beryllium, Platinum, Lead, Silicon
  1. Header Pins= Gold, Nickel, Copper
  2. Card Fingers=Gold, Nickel, Copper
  3. Platters= Cobalt, Platinum, Chromium
  4. Card Sockets=Copper, Beryllium, Gold
  5. Hard Drive Housing= Aluminum
  6. CdRom Drive Housing= Galvanized Steel
  7. Floppy Drive Housing=Galvanized Steel
• CPU Heat Sink= Aluminum
• CPU Retainer= Spring Steel
• Keyboard=Plastic Housing, Neoprene Buttons, Mylar Sheets printed with silver.

This is just a quick overview and requires more detail to point you to the exact quantites, but you get the idea.

Steve

 

[CFirehawk]

You guys are absolutely awesome. Today I did okay for a first parts run, but not good. Not gonna do it again on a sunday, but I have more stuff to practice on. Seems PCs are the best free sources of stuff, and I don't have the experience/gear to start evaluating jewelry. Thats why I wanna learn them in detail, it wasnt hard to walk into a shop and ask for fried boards.

 

[PhillipJ]

Hi Firehawk.

You are going to find a lot of work to get the gold out. Mostly the gold is what you can see with the eye. Sometimes you may find gold in certain older black chips. You'll have to crack them open to see it. They are more on old military boards. The common black IC's don't really have any value that I know of.

The easiest to get gold is in the CPU's & fingers. Pins you'll have to work for. Sort out your different items. Each one gets processed a little different. Plus, you get an idea of how much gold is in certain items after you process them & do the math.

You might even want to write down your return for certain types of scrap. That'll help you know what something is worth if you ever want to pay for any scrap. Plus it's help you to know how much acid to use.

Make sure you save all the copper, aluminum and steel. And recover the copper from your acids too. I am of the opinion that all that suff has more value than the gold.

Have fun.

 

[aflacglobal]

Make sure you save all the copper, aluminum and steel. And recover the copper from your acids too. I am of the opinion that all that suff has more value than the gold.


Amen :wink:

 

[CFirehawk]

That fits right in with my total recovery recycling plan.

 

[hyderconsulting]

I'm just adding a subnote to what badastro said about electrolytic capacitors which is completely true. Some of the larger electrolytics found in electronics and other electrical equipment can be salvaged and sold to electronics hobbyists for their DIY projects. I do it all the time on ebay. These are the wire post mounted ones and not the small ones soldered onto circuit boards in PC desktops. Although the capacitors are aluminum they do not fall into any aluminum scrap grade because of the chemicals inside of them. At one time I had an aluminum processer considering purchasing them for scrap but I didn't push him hard enough at the time. If aluminum ever gets very high in price then someone will probably figure out how to make money from them. Regards, Chris.

 

[Anonymous]

hi...can someone post a pic of the electrolytic capacitors that hyderconsulting was referring to? if they sell on eBay, i'd like to make sure i save them when i salvage through computers...and i want to make sure i pull the right things...lol. thanks!

 

[lazersteve]

Welcome to the forum,

Here's a link to a post with photos of the aluminum capacitors:

Capacitor Post

Steve

 

[aflacglobal]

I think this is what hyder was talking about.

 

[badastro]

Those capacitors are bought on ebay by experiementers working on coilguns and such. I've never seen one big enough to warrant selling in an average computer.

 

[aflacglobal]

That's the confusion. He's not talking about computers i don't think.

Hyder-Some of the larger electrolytics found in electronics and other electrical equipment These are the wire post mounted ones and not the small ones soldered onto circuit boards in PC desktops.

Like microwaves, hvac fan units, motor starters, and so on.

 

[lazersteve]

hi...can someone post a pic of the electrolytic capacitors that hyderconsulting was referring to? if they sell on eBay, i'd like to make sure i save them when i salvage through computers...and i want to make sure i pull the right things...lol

Looks like he was talking about both types...


Steve

 

[badastro]

Those large screw terminal capacitors are not found in microwaves. They are found in very large power inverters and some big uninteruptable power supplies. Anything with an electrolytic capacitor worth selling will be big and powerful. They aren't found in average scrap. If you do come across scrap with those capacitors, there are expensive semiconductors worth selling, too. Though they are just worth a few dollars.

Those big capacitors are also very expensive. A small one, new, will cost about 100 dollars while a big one might cost over 500 dollars new for just one. Their used price is 1%-10% of their original cost on ebay.

Microwaves have oil filled capacitors, a diode, and a transformer, as well as a magnetron. The microwave capacitors are rated for about 2kVAC and very low capacity. Together with the diode, it forms a voltage doubler to power the magnetron tube. All components of microwaves are nearly worthless for resale as people who might want these components can get them by finding a microwave the dump. If you get about 50 microwave capacitors, you might be able to sell them to a high voltage experimenter.

The transformers are valuable for the copper (they have a lot of copper), but you have to break open the steel to get the copper. The magnetron has very powerful magnets that you might be able to sell, and the magnetron tube is mostly copper, but the ceramic might contain beryllium oxide due to the high frequency nature of the device.

Large fans and motors have what are called motor start or motor run capacitors depending on what kind of motor it is. These capacitors are oil filled metal can capacitors that have little or no value to anyone. You might be able to find someone who will buy them for less than the cost of shipping. They are too low voltage to be useful to high voltage experimenters.

Capacitors with resale value are physically large and heavy. Higher voltages are better. To a high voltage experimenter, it is the energy storage capacity of a capacitor that determines its value. Anything less than a few joules is worthless unless the capacitor is rated for several kilovolts. These capacitors are also very dangerous as they can hold a charge for very long periods. They should be stored with the terminals shorted with a wire.

Some very old oil filled capacitors contain PCB's. Those capacitors have no value and are considered toxic waste. If they are leaking oil all over the place, you'll probably have to call a hazmat team.

 

[Harold_V]

Some very old oil filled capacitors contain PCB's. Those capacitors have no value and are considered toxic waste. If they are leaking oil all over the place, you'll probably have to call a hazmat team.

Avoid PCB's like the plague.

I've been involved in the disposal of them on two different occasions. One of them concerned four large water cooled capacitors from an induction furnace. Cost of disposal was slightly greater than $1,000, and that was about 14 years ago.

Such material must be properly packaged and shipped to one of very few incinerators that are properly licensed for such disposal. One of them is in Coffeyville, Kansas, as I recall.

Harold

 

[Anonymous]

thanks for all the info guys...i think i get an idea now of what was being discussed (regarding the capacitors). also good to know that there isn't much to salvage from microwaves...i was about to tear one open today...lol.

 

[goldsilverpro]

In the old days, before legislation, many scrap metal yards dumped a lot of PCB's into the ground. Their main thing was scrapping out huge oil filled transformers, loaded with big copper slabs. Some of the transformers were 5 feet tall. They would bust open the case - build a pyre of scrap lumber, from pallets, around it, several layers deep - pour 50/50, gasoline/diesel on it - fire it off - remove the copper slabs. I would guess that some of them contained a ton, or two, of copper.

 

[Harold_V]

Oh, yeah! I've talked with guys that said that they also used to use PCB's as a solvent for lots of things. Even cleaning their hands. While I don't doubt it's a carcinogen, I have a question about how serious it is to be exposed. Maybe PCB's explain the problems many people have with their health. Or not!

Reading about the disposal is interesting. As I recall from long ago, if the combustion temperature isn't correct when it's incinerated, it has a way of recombining in the stack, so it isn't destroyed, just disseminated over a large area.

They had opened a new incinerator in Utah about the time I had to dispose of a transformer and one capacitor, a different proposition from the other incident I mentioned. They had been having trouble getting certified because of the recombining problem, so my lot of things couldn't be shipped to that facility.

A report I read some time ago suggested that there are certain microbes that digest the stuff, rendering it harmless. Cleanup of soil can be a lot less troublesome by that method.

Harold