Respectfully disagree @Fish007. I'd be more than surprised if...

Respectfully disagree @Fish007. I'd be more than surprised if they can use the existing mill - it was old when it came over from Africa in the 1980's (I dont know if it actually did but most mills of that vintage were imported for about $5M each at the time, Bounty, Wiluna, Tarmoola, Sons of Gwalia, New Celebration, etc...), and has been rusting away for more than 20 years. And I'd say it's probably not built for non-refractory material. If they try to use it, they'll be in a world of pain for many years trying to make it work. It's been tried many times before with the same outcome.

Technology has come a long way since then too. They will want something modern, that can do both non-refractory and refractory. And sized properly for the operation. To do that they need a good case to take to the market, which means a good Mineral Resource. Given that ROX are still in discovery mode at Grace I'd say 6 months at the earliest. Then you do a PFS, 6-9 months, and hopefully start the permitting process at the same time.

Then the FS starts, same again, because by then you've got a different Resource and are probably wanting to include the underground (which was a dog of a thing even for the 90's - 1:6 decline, 16m radius curves, highly refractory (actually, come to think of it, that might have been Gidgee, I could be wrong on that point. Back when I was with Apex they were thought of as the same project. The Youanmi mill didnt even come into consideration back then and refurbishing the Gidgee mill was going to be a big job even though it had been running only 3 years earlier, in 2005). Either way, you still need to go through the steps, skipping straight to FS always comes unstuck, always. Classic mistake of Exploration companies who think they can become miners though.

Then there is FEED, Front-End Engineering and Design - when you actually design the mill and take it to tender, maybe another 3 months if nothing tricky involved. That can start at the same time as mining if you've got permits and financing in place and a decent pre-strip, or it needs to start earlier if the gold is near surface. Then you have to build the thing, commission, etc... Long lead items such as motors and mills could be 9-12 months.

Realistically - best case 2½ years. More likely 3. Not allowing for another 12 months of Covid shutdowns to international travel, etc... Unless they have already come up with something completely out of the box.