SMD resistor carbon film bad for Aqua Regia?

[924T]

Howdy, all!

I was just wondering if the carbon in SMD resistors, which is in the form of a film, would adversely affect
Aqua Regia?

The reason I ask is that I've got a mixture of MLCC's and SMD resistors, and once I get past the boiling in
HCl phase, I don't want a big surprise/mystery when performing the boiling in AR phase.

Cheers,

Mike

 

[jeneje]

Mike,
Did you incinerate first, before the HCL? Just curious.
Ken

 

[924T]

jeneje,

Thanks for responding!

I haven't done anything yet, so I'm trying to be as thorough and cautious as I can.

I wasn't sure what incinerating would do to the MLCC's------I was pretty sure incinerating would burn the
carbon out of the SMD resistors, but was totally unsure if any actual values would go up in smoke, too.

Would the carbon act as an absorbant medium in AR, thus capturing solution that held values, which
would be a bad thing?

Cheers,

Mike

 

[jeneje]

jeneje,

Thanks for responding!

I haven't done anything yet, so I'm trying to be as thorough and cautious as I can.

I wasn't sure what incinerating would do to the MLCC's------I was pretty sure incinerating would burn the
carbon out of the SMD resistors, but was totally unsure if any actual values would go up in smoke, too.

Would the carbon act as an absorbant medium in AR, thus capturing solution that held values, which
would be a bad thing?

Cheers,

Mike

Mike,

I am not sure about the carbon being an absorbent, If it were me i would separate the magnetic pieces from non magnetic. Incinerate until the carbon has been ashed (turned completely white) Then using a mixture of 50/50 nitric and distil water leach the silver and palladium out. Filter, wash and cement values with copper.

AR has very little effect on dissolving silver. If you suspect Pt, save the material after the leaching, wash well with hot water and then use AR to remove any PGM's that may still be there.

Hope this helps you some,
Ken