Gold powder smells like H2S

[nickjam]

Hello everyone:

Finally done with my first batch and everything went great! Used the HCl and Bleach method and SMB to precipitate out the gold. Now, I know SMB makes H2S, but I washed the gold powder with HCl once and then 3 times with DI water. I am drying the powder to almost dry in a pyrex beaker, then air dry to a finish. Once the heat plate the gold powder started to smell like rotten eggs (H2S) when it began to steam. Is this normal? No searches have brought up this question and I missed this detail somewhere if this is normal.

If it is not normal how to I remedy this issue?

Thank you!

 

[Lino1406]

SMB wouldn't make H2S. What was your source material?

 

[archeonist]

The same here, I think this is caused by an excess SMB. Even after several washes there is still some SMB left. I think the SMB decomposes due to the heat. Maybe some SO2 evaporates or some elemental sulphur, wich can cause the white smoke. It is definately not H2S wich is a gas, gasses are not visible except gasses that do have a color like NO2 (brown) or Cl2 (green).
I always keep applying heat till no smoke is visable, after this step the powder always looks a lot cleaner. Don't breathe too much SO2 it is toxic.