Processing a rare earth mineral deposit using gravity and magnetic separation

• Magnetic properties of rare earth and gangue minerals measured using a vibrating sample magnetometer.
• Honda–Owen analysis used to isolate paramagnetic behaviour of RE minerals.
• Falcon concentrator and WHIMS used to concentrate RE ore.

Rare earth (RE) mineral deposits are typically processed using several different unit operations including flotation, gravity, magnetic and electrostatic separation techniques. Two of the most important beneficiation techniques for RE minerals are gravity and magnetic separation. Many RE minerals are found alongside low specific gravity gangue minerals thereby permitting the use of gravity separations to concentrate the heavy value RE minerals. Magnetic separation is used primarily to remove ferromagnetic gangue minerals as well as to separate individual paramagnetic rare earth minerals.This work investigated the use of a wet high intensity magnetic separation (WHIMS) in conjunction with gravity pre-concentration steps (Knelson and Falcon centrifugal concentrators) to beneficiate a rare earth ore. The results of these separation steps are related to the magnetic properties of RE minerals, based on literature and measurements conducted using a vibrating sample magnetometer (VSM).