# Hot plate



## Axlrod2 (Apr 27, 2012)

Has anyone heard of a hot plate to melt gold and keeps the other metals away?


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## butcher (Apr 27, 2012)

No I have not.


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## acpeacemaker (Apr 27, 2012)

I've seen industrial hot plates that can get up to 575F. Not really close to melting gold. If you have an alloyed scrap, lets say gold, silver, and copper. How would you expect to melt this down and extract just the gold from the other two just by melting? I've seen people speak of melting and pouring into cone molds. But, also I've seen others say forget that it's nonsense.
Are you thinking more of something along the lines of a fire assay?


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## butcher (Apr 27, 2012)

You can dissolve gold into solder at a much lower melting point than the gold, solder has a real low melting point, gold has a very high melting point, but when these two metals come into contact with heat both of there melting pints change the solder will dissolve the gold into it and make a new alloy of a different melting point than the two separately have. 

So you can make an alloy but you would not separate them.

In an assay sometime lead or other metals are used as collectors, some base metals in the melt can be oxidized and dissolved into the slag glass with the assistance of a proper flux the metals can also be oxidized or reduced, the flux, metals and heat perform this chemistry in the melt, so we can separate some of the metals this way, also with a cupel can be used to help absorb some of the oxidized metals, this reaction is also assisted with heat and air. So we can recover the values using some of these methods.

But not of this has anything to do with separating values with a hot plate.

On the forum we explain how we use our hotplates and acids to recover and refine gold, also Hoke’s book will teach you how.


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