[TheForge] reclaiming copper

[terry l. ridder]

hello;

comments below.

On Thu, 29 Jun 2006, Dan Brewer wrote:

>
> Melting copper in a steel crucible is like putting hot water into a spun
> sugar cup. It will find a way out. The crucible will get much hotter than
> the contents. Yes you can get away with it a couple of times but any
> weakness in the crucible will soon be found by the molten copper.
>

i really have to ask how you can make the above comment when you have no
detailed information nor knowledge of the steel crucibles i would be
using. your condescending tone is a real turn off. just because you make
the above statement does not make it in any way true.

>
> The Flux you need to trap all of the crud you are burning off
> the copper is borax.
>

i really do not see the need for borax.

>
> Not just carbon.
> Copper oxidizes very rapidly at temp.
>

a reducing atmosphere will keep the copper from oxidizing in the
crucible furnace. the addition of charcoal and/or coal ensures that.

>
> The flux keeps the copper clean.
>

the reducing atmosphere keeps the copper clean.

>
> Copper oxide melts around 2500 deg F.
>

which oxide of copper are you referring to?

Systematic name     Copper(I) oxide
Molecular formula   Cu2O
Melting point       1235 °C (1508 K) 
Decomposition to Cu + O2    1800 °C (2070 K)

Systematic name     Copper(II) oxide
Molecular formula   CuO
Melting point       1326 °C (1600 K)


however, in a reducing atmosphere, either copper oxide will not be
forming. whatever, copper oxide present was all ready present in the
cable and wire.

>
> Just my 2 cents worth
> Dan
>
>

-- 
terry l. ridder ><>