The first considerations are at what point in the process the crusher will be used, the type of material, and the output required. Use the table above as a guide.
1. A typical example of primary crushing is reducing topsize from 900 to 300 mm.
2. A typical example of secondary crushing is reducing topsize from 300 to 100 mm.
3. A typical example of fine crushing is producing concrete aggregates in fractions below 30 mm.
4. Manufactured sand is typically smaller than 5 (often 2) mm.
5. Typical abrasive rocks are Granite, Quartzite, Diorite, Trap rock, Basalt, Gneiss - Abrasion index above 0.10
6. Typical non-abrasive rock is clean Limestone (Marble) - Abrasion Index below 0.10
7. Fines or ”0-X mm” material is normally below 2 mm-0.075 mm is called filler