4. Design of crushing and grinding plants for rock materials

4.1 Coarse crushing

The primary crushing facility is a vital part of the plant, as it is at the head of the circuit and sometimes receives huge blocks. Consequently, the size and structure of this plant must take into account :

• the capacity of trucks and machinery; in particular, 20 to 38 m ³ shovels are used to load crushers, and 150 to 320 t trucks;

• the almost general need for a grizzly (bar grate or fixed rails) at the crushing head;

• storage before and after the crusher;

• maintenance operations requiring suitable surfaces;

• the fact that the crushing operation...