I've done a little more digging today.
@NavyDiver you triggered this, so you might be interested.
US Publication from 2017 talks about the criticality of Antimony, and there's been more since but this is a pretty comprehensive 'critical minerals' report. Antimony starts on Page 65.
https://pubs.usgs.gov/pp/1802/pp1802_entirebook.pdf
The interesting bits I took from this is that Lead Batteries need 99.9%+ antimony, and superconductors need 99.999%+ (no surprise there). Usage of antimony in 2012 is as per below:
Nowadays, 5-10% is in electronics, and 60-70% is in batteries. Much better for us
Unsurprisingly the tonnage in superconductors wasn't enough to show on the pie chart, but the lead batteries are included there.
There is a smelter in the USA, on top of an old mine for which they no longer have JORC resources nor do they mine from, but they do import to smelt. Their website is below, and they are still active
https://www.usantimony.com/about
Another more interesting (and current - 2020) paper talks to the supply chain as a whole. Really interesting graph shows the global flow of antimony
https://perpetuaresources.com/wp-content/uploads/Antimony-White-Paper.pdf
Interesting to see Hilgrove on there and that it's ceased (obviously). More interesting to me is that the original consumers were in Mexico, which (if you read the US Antimony Smelter company info, sources a lot of beneficated ore from Mexico.... and they are still in production.
Other roasters outside China are in Bolivia, Italy, but notably Oman.
https://www.spmp.co.om/
The Oman smelter is still coming up to speed from what I gather, as production data isn't publicised and feels like it's still got some challenges.
However.... to my early concern around "where could Hillgrove export to", and "who on Earth would actually sign an offtake for the Sb AND be able to refine it straight away, instead of stockpiling" I now feel a little happier. The USA supply chain (through Mexico) it still a key opportunity. The Oman option is also a potential, as it sounds like Oman will need feedstock and is focussed around Gold / Antimony, therefore probably shares some similar benefits and challenges in processing it.
Remaining question for me is the level of concentrate produced at Hillgrove historically, and whether or not the $70m restart considers or accounts for any enhancements to this process.
(20min delay)