The presence of a large fraction of substandard material at the outlet of a cone crusher is a sign of a fault: an incorrect cone clearance, incorrect feed rate, wear and tear on working parts, or malfunctions in the hydraulic control system.
Oversize material from a cone crusher – that is, oversized fractions in the output – does not occur by chance; but is a signal from the equipment itself indicating hidden or obvious operational faults; identifying the root causes will help to make timely adjustments and prevent costly downtime.
A cone crusher operates on the principle of compressing the material between a moving and a stationary cone; if the working gap between them exceeds the design value due to wear on the wear plates or incorrect drive adjustment, the material does not receive sufficient crushing force and is discharged in the form of large chunks.
If the feed is uneven, with variations in volume or containing particles larger than the permissible size for a particular crusher model, the equipment is unable to process the incoming flow in time, some of the pieces pass through the crushing zone without sufficient compression, resulting in oversize material.
The armour plates of the moving and stationary cones are subjected to constant abrasive wear from hard rock; as they wear naturally, their surface becomes smoothed, the sharp edges capable of splitting the rock into pieces are lost; as a result, crushing becomes less effective and the proportion of coarse material increases sharply.
The hydraulic mechanism is responsible for maintaining a stable working clearance and compensating for minor wear on the armour plates; if there are leaks of working fluid in the system, a drop in pressure or valve malfunctions, the clearance increases spontaneously, leading to the presence of large particles at the unit’s outlet.
