On Wed, 25 Jul 2007 10:45:30 +0100, Eeyore
wrote:



Spurious Response wrote:

Eeyore wrote:

Personally, I can think of no good reason to attempt to 'recycle' old printed
circuit boards. For example it appears to be both uneconomic and likely energy
wasteful too.

If one (read a business) had an incinerator for refuse, which is common
in the US, one could very easily have enough heat energy "left over" to
reflow, and "Smack and Gather" soldered assemblies after they reach
reflow temperatures.

It would not take long to gather a ton of "solder".

A ton is a ton is a ton, and gathering several grams from each assembly
one has for salvage makes the planet more "green", because reprocessing
lead, and lead alloys is far easier and less costly than mining it.

Incinerators are now deprecated since the greenies say they make dioxins.

Fully operating incinerators are sprinkled all over this country. There
was even some twit on TV the other day claiming that their placement was
racist.

Actually, I'd expect a lot of solder to turn to oxides and go up the smoke stack if
subjected to high temps.

Do you know the rate that pure Lead oxidizes? Do you know the rate at
which 63/37 Tin Lead Solder oxidizes at?

Bullets are still being found in old US Civil War battle fields, and
they are practically pristine balls. No crust whatsoever.

What actually happens with pure Lead is that it's first few mils of
depth become "tempered", similar to aluminum anodization.

So it becomes harder, and would oxidize even less.