SMD resistors - any value ?

[Mech]

Title is the question , surface mount resistors , have a pickup load of them .
My local surplus place has too many so will not buy or trade .
Haven't checked with local scrap yard , yet
But with this much volume , if there is any silver ? it could be worth it ?

Still do prospecting for gold .
And do electronics repair , between those I got into getting gold mostly from electronics .

 

[Alondro]

The little flat resistors are ruthenium oxide... and you REALLY do not want to try recovering ruthenium. It does not play nice with life.

The bulky old ones SOMETIMES have some PM plating inside the end caps, rarely plating the entire cap (mostly high-end old boards. I found a few gold-plated ones on a 1970's board from testing equipment). But even then, it's unlikely ALL the resistors even on the BEST boards will have anything.

Big resistors from consumer-grade boards... just assume there's nothing. Toss em.

 

[adam mizer]

I ran some smt resistor test batches a few pounds, years ago.
The resistors were from mid 90's to 2000.
Ran in AR and probably should have run a second time to get everything.

Got some palladium from them, can't remember how much maybe a gram per pound.
Processed a second time lost some weight due to other metals.

My understanding is earlier the better for PGM's.
Can't remember all the details.

Use the same method like mlcc's.
The fine ceramic dust made filtering tough I believe on washes but doable.

EDIT: just saw Alondro;s post about ruthenium. Maybe thats what I have.
I think I dropped from solution using zinc, so only had pgm black powder but I faintly remember processing palladium yellow.
Older the better I remember reading at one point they did use palladium.

 

[Alondro]

I ran some smt resistor test batches a few pounds, years ago.
The resistors were from mid 90's to 2000.
Ran in AR and probably should have run a second time to get everything.

Got some palladium from them, can't remember how much maybe a gram per pound.
Processed a second time lost some weight due to other metals.

My understanding is earlier the better for PGM's.
Can't remember all the details.

Use the same method like mlcc's.
The fine ceramic dust made filtering tough I believe on washes but doable.

EDIT: just saw Alondro;s post about ruthenium. Maybe thats what I have.
I think I dropped from solution using zinc, so only had pgm black powder but I faintly remember processing palladium yellow.
Older the better I remember reading at one point they did use palladium.

Some of my very old ones from the 70's have a very pale silvery plating that does not tarnish and is not aluminum. I suspect it's silver-palladium alloy, but I only have a small number of them and keep them in a jar to test later when I have spare time. Right now, gotta strip 3 huge tubs of boards (as well as replace the house siding and do other critical repairs).... way too busy to bother with 1/4 pound of resistors for now!

 

[adam mizer]

This video Dusan999 got silver.


Then this old post, I can't find my finish after reprocessing. But I did save a much smaller amount. Here's a link.
Still inconclusive as I am not very experienced.
https://goldrefiningforum.com/threads/pms-in-surface-mount-components.10838/

PM's in SMD's mostly resistors and there was a few caps in there, 100% off tape reels dated late 90's.
Total material dry weight was about a 1 pound (16oz).
Material sat outside in the sun for near a month while removing any tin/lead solder in HCl bath being stirred from time to time and changed out for fresh HCl while removing base metals.

Tested stannous, palladium and some slight platinum maybe.
When dropped with zinc I noticed the palladium sank very quickly.
Pulled all the palladium out and tested the pour off (addidtional zinc added) and got some more. Again another test and additional zinc, and appears maybe 1/2 gm of platinum (I think) fine powder material and just over 8gm palladium powder.

The pic shows the palladium powder removed.
The HCl/Cl wash out with super deep red stuff on left with most of values and still pretty deep color on right as I leached out the components.

There is a picture showing result of a stannous test on a swab.

EDIT ADD: this can be searched for hours and you can find where AG and PD is used in chip resistors. This video is on TPNU chip resistors.


I keep finding an AG/PD in chip resistors, too much ***** searches.
Time for more coffee.

Edit by moderator, removed offensive word.

 

[Yggdrasil]

This video Dusan999 got silver.


Then this old post, I can't find my finish after reprocessing. But I did save a much smaller amount. Here's a link.
Still inconclusive as I am not very experienced.
https://goldrefiningforum.com/threads/pms-in-surface-mount-components.10838/


There is a picture showing result of a stannous test on a swab.

EDIT ADD: this can be searched for hours and you can find where AG and PD is used in chip resistors. This video is on TPNU chip resistors.


I keep finding an AG/PD in chip resistors, too much ***** searches.
Time for more coffee.

Edit by moderator, removed offensive word.

I think you may have meant something else here?

 

[Mech]

I picked these up from a warehouse 2-3 yrs. ago .
Did not ask age .
Have check printing on boxes to see if there is something that indicates date of manufacture , guessing total age maybe 5 or so yrs.

At time only working with hydrochloric acid with connector gold from fingers & pins - do not have lab , fume hood so only processing outside .

I think I watched Dusan999 , did not remember till mentioned here , will watch again .

Thanks