ASTM D440

Drop Shatter Test for Coal

Applicability: Applies to lump coal and sized coal intended for storage, transportation, or end-use applications where mechanical degradation during handling is a quality concern. Used to evaluate the resistance of coal to breakage under repeated impact loading, simulating conditions encountered in transfer points, conveyors, chutes, and railcar loading and unloading operations.

Purpose: Determines the drop shatter index of coal by dropping a weighed sample of sized coal from a standardized height onto a steel plate for a fixed number of drops, then sieving the resultant material to determine the size distribution after impact. The percentage of material retained on specified sieves is reported as the shatter index, which quantifies the tendency of coal to break or produce fines during handling. Results are used to predict coal behavior in handling systems, assess suitability for specific end uses, and compare the relative friability of different coal sources or preparation products.