[Muonium]

Hi everyone! When burning crude Antimony metallic ore (Sb, S, As, Pb, Fe) with a propane torch, small powerful explosions occurs, sometimes with blueish-white flames. I thought this was somewhat due to the decomposition of Antimony trisulfide (present in small concentrations) but I then found a paper abstract describing the explosive semiconductor-semimetal transition of Antimony. Can someone relate to this or know anything about it?
Thanks a lot.

[Enthalpy]

Welcome, Muonium!

If sulphur isn't oxidized in your ore (if sulphur is native, or forms metal sulphides), it will burn with air. Sulphur makes a blue flame and stinks like firecrackers.

The rest in unclear to me. Wiki suggests that the unstable allotropes of antimony are absent from ores
https://en.wikipedia.org/wiki/Antimony#Properties

Could there be pockets of water in your ore?

[Muonium]

Hi, thanks! I've burned sulfur and other sulfuring-bearing ores and it never did that. Pockets of water may be possible indeed; i'll try dehydrating it before roasting it.

After further researches, the explosive allotrope cannot exist naturally as you said, and I found that it is most likely the thermal decomposition of Antimony sulfide or Antimony black (dust), or their reactions with volatile/oxidizing compounds released by the high-temperature.

Thank you.