IMPACT CRUSHABILITY TEST

 1.       Ten to fifteen samples of approximately 3” x 2” dimensions with two natural parallel or near parallel side of 2 to 3 inch widths are selected.

 2.       Each sample piece is placed on a pedestal and stuck simultaneously by two opposing hammers of standard size and shape.

 3.       The height of the hammers are increased until the sample is broken and the total foot-pounds (A) of force are recorded. The width (W) of the sample at the fracture is recorded

 4.       The Work Index is calculated from the equation:

                            A

2.59    W

                                Sp. Gr.

5.       Two W.I.’s are recorded. The maximum W.I. and the average W.I. of the samples tested.

IMPACT W.I.

Very Hard                                            Maximum                                           Average

Trap Rock                                            38.79                                                     29.75

Gabbro Rock                                      41.21                                                     24.68

Trap Rock                                            37.84                                                     30.99

Quartzite                                             24.51                                                     19.81

Granite (Fine Grain)                       28.44                                                     20.76

Hard

Lead-Zinc                                            21.14                                                     13.37

Limestone                                          22.27                                                     15.82

Granite                                                 18.10                                                     13.68

Marble                                                 19.71                                                     13.47

Medium

Copper Ore                                        12.23                                                     8.01

Andesite                                             14.19                                                     9.12

Granite (Large Grain)                     19.38                                                     10.33

Copper Ore                                        18.77                                                     10.15

Marble                                                 18.65                                                     9.40

Magnetite                                           18.13                                                     9.38

Soft

Limestone                                          9.00                                                        4.87

Iron Ore                                               8.30                                                        4.73

Shale                                                     8.44                                                        6.07

Bauxite                                                                15.62                                                     6.22

Bauxite Clay                                       10.49                                                     5.79