Point Load Test
A fast and convenient way to estimate the strength and fracture toughness of an ore.
The Point Load Index can be used to simultaneously characterise rock for blastability and comminution processes.
In a Point Load Test, a sample of rock is mounted between two pointed plates and pressure is applied until failure of the sample occurs. The peak applied load is recorded. This is repeated on a minimum of 20 pieces of rock within a sample with the results used to calculate the Point Load Index.
Sample Requirements: Sufficient core to cut 50 pieces with a length to diameter ratio of at least 2.5:1 and a core diameter ideally about 50mm, although 20 to 60 mm is acceptable. Rock pieces in -75+50mm range can also be used - again 50 pieces with 2.5:1 aspect ratio and reasonably parallel end surfaces.