There are two published studies for rare earth clay processing -...

There are two published studies for rare earth clay processing - Aclara Penco (1.9 mtpa throughput) and IXR Makuutuu (5 mpta throughput). Recent broker reports for MEI are strongly suggesting MEI are running with a 5 mtpa throughput. So a 20 year mine life at 5 mtpa is 100 mt of feed, that's all a rare earth project needs provided those tonnes are all the right grade, respond to leaching well, within a mineable pit shell etc. Given the shape of resources, leachability, amongst other factors, you would prefer ~200 mt to give yourself some room to use preferable feed material.

If Sybella is big enough, they could even go for a 10 mtpa plant so you'd be looking at 200-300 mt resource, well below your rough calc. of 400-500 Mt from Boundary Fence East alone. They have hit the same 120 m deep REE grades 6 km North at Donkey Dam, so the rare earth granite could be consistent throughout the 10 km N-S Sybella complex. Step out RC drilling required ASAP to prove up how big of a monster we have on our hands. Also a 500 m deep diamond drill at SBRC016 wouldn't go astray either, we know it's still open at 120 m..

Also note SG of granite is 2.4-2.6, much higher than clay. What SG did you assume in your rough calc?