Vintage pcbs recovery amounts

[Cryptostack88]

I picked up these 3 boards the other day and was just curious if I should just keep them as collectors items or if they were worth trying to recover the PM from? Also, if anyone could school me on the amounts of gold and ither PMs in these types of materials I would greatly appreciate it. I also took apart this old cassette tape answering machine anything valuable on this board? One more question what kinda returns can be expected from gold filled materials?I hope I'm not being a bother. Lol

 

[Ohiogoldfever]

There is a gold filled thread that’s been vary recent. I’m sure you could find it fairly easy.

The wire wrapped pins I’ve done have been a pain but 5-7 grams a kilo.

The ceramic chips should be researched, some of those look like they could be sold as collectors.

Otherwise spend months reading, sorting and recovering. Then you’ll be able to find out for yourself.

 

[Cryptostack88]

There is a gold filled thread that’s been vary recent. I’m sure you could find it fairly easy.

The wire wrapped pins I’ve done have been a pain but 5-7 grams a kilo.

The ceramic chips should be researched, some of those look like they could be sold as collectors.

Otherwise spend months reading, sorting and recovering. Then you’ll be able to find out for yourself.

Cool, thanks!!

 

[Christian333]

Addressing your cassette recorder board.

Red: DIP IC-Dual Inline Pin array Integrated Circuits, potential for solid gold bond wires, PM-Precious Metal plated substrate/leads and PM microchip die braze.

Blue: Single layer ceramic capacitor, potential for silver plating on both sides of the ceramic disk, used as the electrodes.

Yellow: Enameled resistors, slight chance for gold plated end caps, silver resistance wire, if wire wound type and PM film resistive plating on ceramic substrate.

Green: TO 92-Transistor Outline package style transistor, same potential as IC.

Orange: Epoxy dipped tantalum capacitor, sell as is to a buyer, current rate $14.75 per pound.

Janie

 

[Cryptostack88]

I really appreciate your help. I have some other boards could you help me with them as well? If it's not asking to much. Also, I took off one of the yellow square pieces and cut it in half and tested it with nitric and it showed positive for PM. Are those the yellow pieces you were talking about? I'm a complete newbie but, I'm learning and reading a lot slowly. I've also accumulated a lot of material kinda before I really understood what was really all involved with recovery. If you could help me with identifying some of the chips, capacitors, resistors, etc? I really appreciate your response/help with my post.

 

[orvi]

I did once the similar pin arrays. Hard to process well with hydrometallurgy, but I had sobering 1,5g/kg Au from these (not exactly these ones). Gold lid ceramic ICs are very good for recovery, low metal content, high Au content. Most of the times more than 10g/kg for smaller ones. As the chip is bigger, ratio of "dead weight" of the ceramic start to be significant and you go down with value per kg pretty quickly.
CPUs could be selled as collector items in my opinion (if you does not have hundreds of them), if they aren´t soldered, but inserted in some socket ( tho can be extracted unharmed ). You can sell them for slightly above price of contained gold and they will go away more quickly

4 side legs SMD chips are classic for gold recovery, myriad of threads here discussing yields from these. From nothing to few grams/kg Au for these. 1g/kg would be fairly decent yield.
DIP plastic ICs on relatively modern boards are hit or miss. Crack one open with pliers and observe if the leads under the plastic are gold plated. If they are, you are onto something. Otherwise it would be practically worthless for procesing on your own. They can be selled to companies tho, so do not throw them away, but sell directly. Older types here are going somewhere around 10euros/kg.

Tantalum in plastic package is also better sold as is. Processing is messy and tedious, for few grams of silver and few % Ta they contain.

On the board with gold-lid DIP ceramic ICs, you have cylider-shaped metallic caps. These are probably tantalum caps also. Also good to sell them directly. They are pretty heavy so better for you

Small blue or grey capacitors around the gold lid ICs could potentially be monolithic ceramic caps or even THT packaged MLCCs. Could contain palladium possibly. Even old monolithic caps contain palladium in some instances. Crack one with pliers and observe if there is rolled foil inside or ceramic inner body. If ceramic, you can test them by crushing one or two to small pieces and dip it in few drops of AR. Then after heating and leaching for few minutes test with stannous chloride to see if some Pd is present.
Also I saw few "dog bones" silver mica capacitors. Brownish-violet in colour. They contain some Ag foils, but for weight, not to much, around few%.

 

[Christian333]

I really appreciate your help. I have some other boards could you help me with them as well? If it's not asking to much. Also, I took off one of the yellow square pieces and cut it in half and tested it with nitric and it showed positive for PM. Are those the yellow pieces you were talking about? I'm a complete newbie but, I'm learning and reading a lot slowly. I've also accumulated a lot of material kinda before I really understood what was really all involved with recovery. If you could help me with identifying some of the chips, capacitors, resistors, etc? I really appreciate your response/help with my post.

The only square yellow components I see on the cassette board are these metalized polyfilm capacitors. They do not have any precious metal value. If you tested with nitric acid it will not dissolve the aluminum.

When I mentioned yellow, it was referencing the color of dot I put on the enameled resistor.

Happy to help, any time.

Janie

 

[Cryptostack88]

I did once the similar pin arrays. Hard to process well with hydrometallurgy, but I had sobering 1,5g/kg Au from these (not exactly these ones). Gold lid ceramic ICs are very good for recovery, low metal content, high Au content. Most of the times more than 10g/kg for smaller ones. As the chip is bigger, ratio of "dead weight" of the ceramic start to be significant and you go down with value per kg pretty quickly.
CPUs could be selled as collector items in my opinion (if you does not have hundreds of them), if they aren´t soldered, but inserted in some socket ( tho can be extracted unharmed ). You can sell them for slightly above price of contained gold and they will go away more quickly

4 side legs SMD chips are classic for gold recovery, myriad of threads here discussing yields from these. From nothing to few grams/kg Au for these. 1g/kg would be fairly decent yield.
DIP plastic ICs on relatively modern boards are hit or miss. Crack one open with pliers and observe if the leads under the plastic are gold plated. If they are, you are onto something. Otherwise it would be practically worthless for procesing on your own. They can be selled to companies tho, so do not throw them away, but sell directly. Older types here are going somewhere around 10euros/kg.

Tantalum in plastic package is also better sold as is. Processing is messy and tedious, for few grams of silver and few % Ta they contain.

On the board with gold-lid DIP ceramic ICs, you have cylider-shaped metallic caps. These are probably tantalum caps also. Also good to sell them directly. They are pretty heavy so better for you

Small blue or grey capacitors around the gold lid ICs could potentially be monolithic ceramic caps or even THT packaged MLCCs. Could contain palladium possibly. Even old monolithic caps contain palladium in some instances. Crack one with pliers and observe if there is rolled foil inside or ceramic inner body. If ceramic, you can test them by crushing one or two to small pieces and dip it in few drops of AR. Then after heating and leaching for few minutes test with stannous chloride to see if some Pd is present.
Also I saw few "dog bones" silver mica capacitors. Brownish-violet in colour. They contain some Ag foils, but for weight, not to much, around few%.

Wow!! Thanks a lot.

 

[Cryptostack88]

Wow!! Thanks a lot.

Wow!! Thanks a lot.

I've been super busy today but, I really appreciate your time with the response.

The only square yellow components I see on the cassette board are these metalized polyfilm capacitors. They do not have any precious metal value. If you tested with nitric acid it will not dissolve the aluminum.

When I mentioned yellow, it was referencing the color of dot I put on the enameled resistor.

Happy to help time.

Janie

Yes, I'm sorry about that. After looking closer I noticed you maked the items with the color dots which I appreciate greatly. Is there a database somewhere with all this kinda information available? I have a few more boards if anyone feels gracious enough to help some more. Really, thank everyone for your all your help.

The only square yellow components I see on the cassette board are these metalized polyfilm capacitors. They do not have any precious metal value. If you tested with nitric acid it will not dissolve the aluminum.

When I mentioned yellow, it was referencing the color of dot I put on the enameled resistor.

Happy to help time.

Janie

 

[Cryptostack88]

I've been super busy today but, I really appreciate your time with the response.

Yes, I'm sorry about that. After looking closer I noticed you maked the items with the color dots which I appreciate greatly. Is there a database somewhere with all this kinda information available? I have a few more boards if anyone feels gracious enough to help some more. Really, thank everyone for your all your help.

 

[Christian333]

Cryptostack88
Start here with reference designators, they are usually printed in white next to each component.


https://en.m.wikipedia.org/wiki/Ref...biguously identifies,number, e.g. R13, C1002.
Janie

 

[Christian333]

Cryptostack88
Once you know the component name, look up which ones contain precious metals.

Janie

 

[Christian333]

 

[Christian333]

 

[Ohiogoldfever]

The silver caps are top hat transistors. They can be pretty high in gold values. Some are better than others. They can be cut open with side cutters. I save them all.

The sliver tubes can be TA capacitors. I’m my opinion worth keeping for a day when silver prices go up. Squeeze them with pliers or cutters. If they are hard, keep them. If they crush easily they are film caps and not worth keeping.

The little yellow hot dogs are MLCCs keep them for possibilities palladium.

One thing to keep in mind is that many components have package types. Meaning you could have two totally different components that look very similar. As you go along you will learn what’s what. It just takes time.

If you have any question about a part just pluck it off and toss it into a Misc parts bucket.

Any chips or pads that have a white ceramic could have beryllium, very nasty stuff. Just leave them alone. Even if they have gold legs. Pitch the gold, keep your health.

Also watch for mercury, it’s found in some switches and relays. Best left alone. Look up mercury relays on google. Once you know what they are they can be easy to spot.

Most importantly just know what your getting into. It takes a lot of little gold covered components to equate to a few grams of gold after recovery and refining. No need to chase something possibly hazardous. Move onto more parts you know.

 

[orvi]

I've been super busy today but, I really appreciate your time with the response.

Yes, I'm sorry about that. After looking closer I noticed you maked the items with the color dots which I appreciate greatly. Is there a database somewhere with all this kinda information available? I have a few more boards if anyone feels gracious enough to help some more. Really, thank everyone for your all your help.

I agree with Ohiogoldfever. Metal case transistors (round cap) anr nice for gold recovery, altough modern types are low in gold. Usually ones with visible gold plating on the legs and bottoms has nice content, just silver bottoms have low to no gold content. I clearly see yours are often gold plated bottoms, from the "pin" that sticks to the side of the metal case Depopulate them with heatgun somewhere outside and try not to burn the boards with high temperature as smoke from the resins isn´t healthy at all. Just soften/melt the tin and pull them out with pliers.

Hot-dogs (brownish-yellow cylindrical things with two leads) can contain Pd, as boards are relatively old. AR+stannous test will tell you for sure. Also the same-coloured flat things with multiple leads could be the MLCCs or monolithic ceramic caps - test them as other MLCCs with AR and stannous.

 

[eaglekeeper]

I see some of these on the boards. Crack a few of them open and see if they have the MLCC's inside. I find these in different colors as well.

The little metal legs are the only thing that's magnetic, which can easily be removed.

 

[orvi]

I see some of these on the boards. Crack a few of them open and see if they have the MLCC's inside. I find these in different colors as well.

The little metal legs are the only thing that's magnetic, which can easily be removed.



View attachment 53041View attachment 53042

That´s the good stuff! Older&bigger the better This was the material which helped me learn how to properly incinerate. Slow and steady, not to burn the solder completely, otherwise it would be tougher to shake it off together with legs in stainless strainer with a heat gun Properly incinerated stuff does not need to be grinded, shaking motion in the strainer will get off all the ashes, with little heat applied also the solder. Losses of PGMs in the solder are negligible from my experience.

It is a nerve saving procedure, as you does not need to deal with ton of tin and lead in the dore afterwards. Espetially tin. Caps are then smelted in induction furnance with appropriate flux, depending on predominant composition of the ceramic.

 

[eaglekeeper]

That´s the good stuff! Older&bigger the better This was the material which helped me learn how to properly incinerate. Slow and steady, not to burn the solder completely, otherwise it would be tougher to shake it off together with legs in stainless strainer with a heat gun Properly incinerated stuff does not need to be grinded, shaking motion in the strainer will get off all the ashes, with little heat applied also the solder. Losses of PGMs in the solder are negligible from my experience.

It is a nerve saving procedure, as you does not need to deal with ton of tin and lead in the dore afterwards. Espetially tin. Caps are then smelted in induction furnance with appropriate flux, depending on predominant composition of the ceramic.

Awesome,
Do you remember yield rates on that type of material.

I have some of these resin coated capacitors I've been saving up and figured incineration would be the best way to liberate the MLCC's from the resin. I'll try the strainer trick to remove most of the Tin and legs. My plan was to grind up the MLCC's and leech the ceramics.... I'm not set up for smelting, maybe one day I'll jump into that area.

Is the silver content in these high enough to act as a the only collector or do you need to add some?

 

[orvi]

Awesome,
Do you remember yield rates on that type of material.

I have some of these resin coated capacitors I've been saving up and figured incineration would be the best way to liberate the MLCC's from the resin. I'll try the strainer trick to remove most of the Tin and legs. My plan was to grind up the MLCC's and leech the ceramics.... I'm not set up for smelting, maybe one day I'll jump into that area.

Is the silver content in these high enough to act as a the only collector or do you need to add some?

I am not familiar with "western" components, but "eastern" plastic coated MLCCs gave from 0 to around 15g/kg Pd.
Incineration is practically only sane way how to start liberating them from the plastic. With few dozen pcs, manual tierdown would be OK, but once you have kilo or so... No way

Depends. Silver content isn´t negligible, most of the time double the Pd content (as far my batches gave this result). If you consider how much dead weight the legs/solder/plastic add, you will be left with practically half the original weight in just ceramics. As I am going to pretty high temperatures (necessary to liquify the ceramic even with right flux), I am not concerned that separation of PGM dore would be impaired. I crushed the slags few times after smelt, but XRF didn´t shown nothing, panning revealed no beads and remelting with copper collector metal get me some miniscule traces of Pd (below 0,05%) in copper, all in all less than 0,2-0,3% of original Pd content, so that does not bother me

But you need to remeber that when you does not go past 1300°C or so, high PGM alloys could be still solid, locked in the slag or does not collect to the one bead at the bottom correctly. Copper or silver are good collectors for Pd, silver being probably better one, as it has lower melting point and eats up less nitric upon dissolution.

Leaching is also an option, but I am not familiar with types of ceramics on more modern MLCCs. And as long as I do not know the composition, it is hard to tell if it actually does work OK. For the old ones with titanate ceramics, it works decently. Alumina may be much more difficult to decompose, if even possible to decompose it by ordinary acids. As for the recovery of Pd out of the ceramics, AR works much better than straight nitric from my observations. But you firstly need to dissolve silver in nitric and then proceed with AR.