Ann: Production Update March 2021 Quarter, page-71

It really depends on the antimony mineralogy. It appears their ore body has both gold and antimony throughout. One strategy in this instance is to use milling, gravity (like a knelson concentrator) followed by cyanide leaching to recover gold. If Sb is not cyanide soluble, your cyanide consumption will be acceptable.

Following gold leaching, the cyanide leach residue can then be ASL leached to recover Sb. Both cyanide and ASL operate in the alkaline region so no risk of HCN formation. You can also operate antimony first, then gold, if cyanide consumption is high from Sb (both approaches are done commercially).

Note that Fosterville have historically processed high Sb/Au ore bodies very successfully for many years, so it is commercially done. Polyus, one of the largest gold AND antimony producers globally, also extracts gold and antimony as separate products from the same resource.

Looking forward to some plans from RVR on the Sb side, as they have focused on gold thus far.