“…It includes heavy medium [ 2 , 3 ], water medium [ 4 , 5 ], and air medium [ 6 , 7 ] separation. The water-medium separation methods include jigging separation [ 8 ], coarse slime interference bed separation (TBS) [ 9 ], and the spiral separation technique [ 10 ]. These methods have unique advantages in they produce easy-to-wash and relatively easy-to-wash coal due to their low sorting cost [ 11 , 12 ].…”