Palladium and platinum containing powder while smelting results in black glass

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Mosana

Member
Joined
Jul 26, 2019
Messages
10
I obtained an acidic solution suspected to contain palladium and platinum so, I sent it to AAS analysis and result showed these two metals inside. I then applied cementation with iron wire and tried to smelt the resulted colloidal brown substance after cementation, with a welding inverter by using graphite rods but it turned black glass like matter instead of metallic platinum/palladium. This black glass shows magnetic properties and attracts to niobium magnet weakly.
My question is that: how can I turn my powder into metal? Is this problem relates to the existence of other base metals (I sure several base metals exist) disturbing proper melting of the powder to metal? and, if I remove the base metals by formic acid, would the problem disappear?
Several times I tried to smelt my powder (both from cementation or ammonium chloride/sodium chlorate) by welding inverters with different amperages but in most cases, black glass resulted and in few times, metal beads appeared in the field of black glass. Oxy-butane torch also results in black glass.
Any guidance is appreciated.
 
Too many variables, but my guess is you got the oxides in the absence of any shielding or reducing atmosphere. What is the amount?
 
Thanks for comment. Yes, without reducing, but I obtained such a powder 2 years ago (in lower amount) and was converted to metal during smelting in the same manner. Only a difference I think occurred this time is the lower current power of inverter.
About 5 g I obtained.
 
Both platinum (around 500C) and palladium (around 1000C) are covered with oxide film on cooling, in the absence of shielding. If the amount is low, the whole mass may convert to oxide
 
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