FINE-COAL CLEANING BY OIL AGGLOMERATION.

When coal in an oil/water slurry is ground to minus-200-mesh in a ball mill, some of the mill energy, normally wasted as heat, can be usefully recovered to help emulsify the oil. If the discharge flows onto a suitable sized trommel screen, water and ash material are rejected through the screen while coal and oil ball together to give a clean product. A small plant has demonstrated the feasibility and the limitations of this process for new Mexico coals.