The milling process is simply the process of grinding the extracted ore down to a manageable size and consistency.

Mountain Pass
At Mountain Pass, ore is hauled to a crushing plant where it is reduced to less than 3/8 inch in size and fed to the ball mill. Fine grinding liberates the mineral grains prior to the froth flotation phase of milling. The flotation operation concentrates the bastnasite ore from an initial 8.5% to a 60% Lanthanide Oxide (LnO) product. An enriched 70% LnO product is produced after flotation with a hydrochloric acid leach which dissolves the carbonate gangue. The bastnasite concentrates are thickened, filtered and dried for shipment or sent to our separations facilities for further recovery operations.

For more information on each phase of our operations please click on the links at left.
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