The slope beyond which the material on a conveyor tends to roll downhill.
The maximum slope on which a conveyor can operate depends on (1) the
material carried, (2) the loading or feeding efficiency, (3) the size and
type of belt, and (4) the environment. In general, in the case of
run-of-mine coal and ore, belt conveyors can operate up to about 18
degrees . If the material conveyed contains large lumps, spillage may
result if the belt is too narrow. Nelson
Dictionary of Mining, Mineral, and Related Terms