# PGM powder Melting



## elfixx (Mar 8, 2011)

That look like the way to go. Looks like some kind of quartz tube can anyone confirm?
http://www.youtube.com/watch?v=ItZ8dvMw3b4


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## lazersteve (Mar 8, 2011)

It must be fused quartz to handle the molten Pt. 

Pyrex would have melted at the temperature of the molten Pt. Of course, it sounds like something breaks near the end of the melting process (a pop) could be pyrex and the sound is the test tube bottom popping?

Steve


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## elfixx (Mar 8, 2011)

Am I crazy or is running at 387 khz?? I just noticed that at the end of the video the machine set up seem to suggest that. And the poping at the end of the melt sounded more like someone flicking the furnace switch off, but I could be wrong.


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## Barren Realms 007 (Mar 8, 2011)

Also sounded like the test tube broke to me as well.


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## Lou (Mar 8, 2011)

Yes, you must run high frequency to melt powders and not start with a heel of metal. Stirring isn't so good (standing waves may form, not deep roiling seen with the usual 12-16 kHz).

Quartz isn't really for platinum--it can be done but the max working temp of quartz is about 1200 C; Pyrex would be a puddle at platinum temperatures. Quartz enters a plastic flow regime around the Pt melt point. It also starts to have a significant vapor pressure (you'll see silica fume if you melt in a quartz dish). Furthermore, it often devitrifies and undergoes the so-called quartz inversion.

Melt it in alumina.


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## qst42know (Mar 13, 2011)

At 19 seconds as the glow is building you can see the vertical fracture up the side of the tube and then again as the glow is fading. Just a bit to the right of center.


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