· The previous mineralogical analyses by AIST in Japan on the grain size of REE minerals in the ore have shown that the reasonable grinding size for the beneficiation would be around 80% passing 50–100 μ select a suitable grinding size the flotation tests were carried out at the grinding size of P80 = 50 μm and P80 = 80 μm by using Aero 704, 845 (in the ratio 1:1) and Aero 6494 as the ...