[ RadSafe ] Re: radioactive contamination of silver

[Glenn R. Marshall]

The melting point of silver is 962C.  The Boiling Point of uranium is 3818C; BP of thorium is 4790C; BP of radium is 1140C; BP of polonium is 962C; BP of lead is 1755C.  So it seems that merely melting the silver will remove only Po from the mix, which is quickly replaced by decay of radium.  Heating the ore to a temperatuure greater than 1140C (but less than the BP of silver - 2212C) would boil off the radium and other short-lived progeny but not the silver.  Does this make sense?

Glenn

-----Original Message-----
From: Franz Schönhofer [mailto:franz.schoenhofer at chello.at] 
Sent: Friday, March 25, 2005 5:08 PM
To: sontermj at tpg.com.au; radsafe at radlab.nl
Subject: AW: [ RadSafe ] Re: radioactive contamination of silver


Mark and RADSAFErs,

That Po-210 must be present in ores of Cu-U-Au-Ag mining is not surprising. That the various procedures of refining of gold, silver and electrolytic refinement of copper which involves several meltings and electrotechnical processes would not remove Po-210 is more than surprising. A very common method to separate and determine Po-210 is based on the volatilisation of Po-210. Therefore I draw the conclusion that traditional methods for silver production should simply by the fact of melting remove any contamination attributable to Po-210. 

I am of course open to any explanation showing that this is not the case.

Franz

Franz Schoenhofer
PhD, MR iR
Habicherg. 31/7
A-1160 Vienna
AUSTRIA
phone -43-0699-1168-1319


> -----Ursprüngliche Nachricht-----
> Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im 
> Auftrag von sontermj at tpg.com.au
> Gesendet: Freitag, 25. März 2005 11:51
> An: radsafe at radlab.nl
> Betreff: [ RadSafe ] Re: radioactive contamination of silver
> 
> Regarding the thread on contamination of silver:
> 
> Can I suggest that an often-unrecognised pathway for silver to get 
> contaminated with radionuclides is from usually-tiny amounts of NORM 
> in the silver ore that can carry over
into
> the final refinery process.  At a
> Copper-Uranium-Gold-Silver mining and processing facility where I was
once
> the RSO, we had to hold
> back the initial silver shipments because we had found unexpected
Po-210
> contamination in it (and Kodak
> didnt want it!).  We made adjustments to the metallurgical process to 
> reduce this carry over.
> 
> Mark Sonter
> _______________________________________________
> You are currently subscribed to the radsafe mailing list 
> radsafe at radlab.nl
> 
> For information on how to subscribe/unsubscribe and other settings
visit:
> http://radlab.nl/cgi-bin/mailman/listinfo/radsafe


_______________________________________________
You are currently subscribed to the radsafe mailing list radsafe at radlab.nl

For information on how to subscribe/unsubscribe and other settings visit: 
http://radlab.nl/cgi-bin/mailman/listinfo/radsafe