Hi

Just a few thoughts/questions:

When we removed tin from pyrolysis columns it was always present as 
bright, shiny droplets.  Little evidence of stable oxide formation.  
After all, we store food products in containers lined with it, whereas 
if you leave a silver spoon in tomato paste or curry overnight you may 
not be very pleased with what happens to it.  I wonder what effects 
sulphur compounds might have?  Silver is certainly highly reactive with H2S.

I looked for the vapour pressures of silver and tin at 1400 degrees on 
the web and from the small amount of information I found, silver seemed 
to have a higher vapour pressure.  I cannot find the numbers now.

The melting points are of course very different: tin at 232 degrees C 
and silver at 962.  This results in the silver building up in parts of 
the column where the gases are still highly reactive, whereas tin passes 
right out of the hot zone.

Like everything in pyrolysis - repeatability is the key.  I'd try them 
both for your applications.

Hil

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