Once gold is made into gold foil can it ever be made into gold ingot again?

Question

I was told if you try to melt it down that about 90% of it turns into gas, how can this be?

Answer 1

Yes, by melting it.  Check your heat source and the melting point of gold for your own comparisons, but an oxyacetylene torch works fine.  Under ordinary conditions it loses practically no atoms as a gas.  It would have to be a virtual vacuum and no gravity for gold to evaporate as a gas!  Some gold foils comes in extremely thin dimensions, so even a full sheet, say a square foot, may contain no more than a half of a single drop of gold - or much less.

I used to work with copper and silver foils for various jewelry projects years ago, and gold-foil came up as a (costly) alternative often...  Melting down foil, unless you get it for free somehow, may be hardly worth the price of the heat needed to melt it - except, yes, the price of gold is rather high these days.....  Might be better just to ball it up into a BB-sized pellet and hammer it down to practically nothing if you need to transport/compress it, but won't remove impurities, of course.

Answer 2

You can made into gold ingot again by just fold the foil tightly and melt it.

Answer 3

It depends on what kind of carrat gold you want the ingot to  be.

gold foil is very low-carrat and ingots are usually high-carrat

so the difference in the carrats would take huge effect

that is why you were told 90% of it turns to gas

Answer 4

yes.  just fold the foil tightly and melt it.

Answer 5

I don't know what was your source of that notion, but it makes no sense. Gold in any form will melt back into a liquid unless the temperature were to be raised above its boiling point. And from that liquid you could pour it back into an ingot.

Rex, in Indiana

Answer 6

A common type of gold foil is a layer of gold laminated between layers of mylar film, and the mylar film is the bulk of the volume.  The gold on this type of foil can be as thin as one molecule thick, but the foil looks like the gold is much thicker.  If this film were heated, you would end up with very little gold.