Hi Kerry,



About 32% of world silver supply is mined as a byproduct of lead-zinc
mining. In those operations for every metric tonne of dry concentrate mined
65% to 75% is lead and between 50 grams (worst) to 2000 grams (best) is
silver.



So, for every tonne of extract (1000Kg), you get 650Kg of lead (worst case)
and between 50 grams and 2 Kg of silver.



So based at 32% being mined this way, to get 1Kg of silver increase
requirement in the market place, you get between 104 Kilograms and 4 tonnes
of lead as a by product.



John





  _____

From: [log in to unmask] [mailto:[log in to unmask]]
Sent: Friday, October 06, 2006 5:27 AM
To: TechNet E-Mail Forum; John Burke
Subject: Re: [TN] "Repeal RoHS" Movement Emerges" a reply




Hi John,
Great response.   One question?  You state (if I have this correct) that you
have to mine much more lead to get the silver.
Why is that?

Thanks,
Kerry

"I will never fly on a jet that has a RoHs sticker on it"





John Burke <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>

10/05/2006 08:50 PM


Please respond to
TechNet E-Mail Forum <[log in to unmask]>; Please respond to
John Burke <[log in to unmask]>


To

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cc




Subject

[TN] "Repeal RoHS" Movement Emerges" a reply











There has been much comment about Dr Ron's article ""Repeal RoHS" Movement
Emerges" in the  industry mailing lists and in correspondence addressed to
me personally. In the article Dr Ron states that in his opinion on the
chances of RoHS (presumeably meaning the lead in solders element of RoHS)
being repealed are "about as likely as me (Dr Ron) beating Tiger Woods in
golf. Not impossible, but..  ". The article can be found here:



http://tinyurl.com/f6g5l







While never having called for a general RoHS repeal, I am and do and have
called for a repeal of the lead in solders ban of that law. I have looked at
the article by Dr Ron which puts forward a series of data and viewpoints on
RoHS based on lead in solders and have taken the opportunity to reply to it
on PCB 007 since the original publication is actually a hard copy magazine
and quite honestly to comment on this in 2 to 3 months time would be
pointless.



My reply and commentary on the article can be found here under the title
"Letter to the Editor: Dr Ron - Dust Off Your Driver! Re: "Repeal RoHS"
Movement Emerges"



http://tinyurl.com/joykv







As I mention in my reply opinions vary.....



Kind regards,



John Burke






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