[TheForge] reclaiming copper

[James Binnion]

Terry,

Dan is absolutly correct. Copper and iron are soluble in each other.I  
guarantee your steel crucibles will alloy with the copper and it will  
dissolve the crucible in short order. Iron based crucibles are  
somewhat ok for aluminum and lower temp metals but no good for hugher  
temp metals.

Jim




On Jun 30, 2006, at 6:03 AM, terry l. ridder wrote:

> 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 ><>_______________________________________________
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James Binnion
jbin at well.com