It might be cost effective if you can export the externalities of rare earth refining. It is a deeply toxic process.

The only reason we don't want to rely on China is geopolitical. Besides that everyone would be happy to have China take the pollution it takes for the rest of the world to transition to electricity.

There are a bunch of steps in the refining process. One of the first step is pulverizing/grinding where you can separate out the constituent components based on density. This step can done locally and will cut the volume of the ore by 75-90 percent.

However, given the regulatory environment in the US surrounding refinement, there is likely a huge opportunity for innovation in this space.