60 Minutes had some coverage of the beneficiation plant.[1] For rare earths, that's mostly grinding and sorting by density and magnetic properties.
It's a large plant near the mine. Bags of rare earth ore worth about $120,000 per pallet come out, and those are transported to the Texas location for the next step, which has a lot more heat and chemistry.
[1] https://www.linkedin.com/posts/60-minutes_rareearths-activit...