Coal preparation plant — Assessment of the liability to breakdown in water of materials associated with coal seams

The principle of the method specified is degrading a test portion of shale in the size range 5,6 mm to 2,8 mm, by controlled agitation in water, determining the proportion of degraded material passing through a 500 µm sieve, and determining the proportion of degraded material of nominal top size less than 10 µm by sedimentation.