The operating logic and control for the vast majority of cone crushers has largely remained basic over the decades. Despite theoretical proof from simulation or from pilot-to-small scale trials on more advanced cone control logic, the control adopted on most modern projects continues to factor in minimal inputs and have only basic control of feed rate to the crusher. Much of this can be attributed to the difficulties in accurately predicting/projecting the many factors that affect the production of a cone crusher over time.
At the Freeport-McMoRan Morenci Canyon Plant, a novel and robust cone crusher operation model was trialed with high-production crushers (Nordberg MP1250) and compared directly against the operation with typical control system logic. This new model – named SmartCone as supplied by Metso – uses four measured inputs instead of the traditional single input (power/amps) and dynamically adjusts not only feeder speed, but also crusher speed along with closed side setting as required.
The target of the system is to maintain optimal production while achieving better mechanical stability and reliability. The testing program consisted of on/off operation of the SmartCone system in order to have direct comparison of the system at the same feed and circuit conditions.
The results of the testing have shown an increase of 8% throughput and 11% specific energy through the crusher, with a reduction in crusher discharge P80 of 4 mm and accompanying higher production of fine particles with SmartCone enabled. Mechanically, the operating conditions also improved with balanced bearing alignment and stable loading as witnessed by oil and RTD measurements.
The promising results have proven the ability of the system to maximise production of cone crushers with consistent product size. Further applications include consistent transfer size to SAG/AG/ball mills or to leach, as well as reducing risk of oversize feed to HPGR with cone crushers operating in open circuit prior to the HPGR.
This is an abstract of a paper being presented at the forthcoming SAG 2023 Conference in Vancouver on September 27 by Dusty Jacobson, Metso USA Director – Process Engineering
