Non-Chemical melting gold powder

[stefano]

How much gold powder ( expressed in Volume / cm3 ) can be melted in a reasonable time ( 15 - 20 minutes ) ?
My tools are :
- Power Mapp burner ( torch ), operation temperature > 1250 °C
- Ceramic crucible 58 mm diameter
- Borax
- Isolation bricks around the crucible for not loosing much heat

 

[Palladium]

That would be a hard question to answer even if you had all the correct information to base the answer on. The most important part of the equation is the heat input or the btu's. You can warm a room up with a candle under perfect circumstances and given enough time or you can use a fireplace and do it in 1/10 of the time required for a candle.

 

[mls26cwru]

much more than about 20-30 grams can become annoyingly hard to melt with mapp gas alone. best bet is to get a torch set up... I have an oxy/propane setup that works wonderfully well even for 10 ounces. the initial cost in bottles can be expensive, but it is a REALLY fun piece of equipment

 

[anachronism]

30-40g in that setup. As has been quite rightly pointed out, any more and you need to look at different gas setups to remain effective.

Jon

 

[4metals]

Try carving out a fire brick like in this thread
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=22206

But you will still hit the limit somewhere between 1 and 2 ounces. It all depends on how much heat escapes.