Chris Hall
Superintendent Geotechnical, Cannington Mine, South32
Cannington mine is a silver lead zinc operation located in north west Queensland. The operation has been in production since 1997. Ore is primarily moved through an underground material handling system comprising of a crusher, conveyor and hoist. The underground crusher and conveyor system were sited in lower grade ore when the mine was first commissioned and a mine design exclusion zone was established around them. As the mine matured, stopping fronts advanced towards the crusher, resulting in an increase in damage of rock mass and ground support within infrastructure areas in the lower parts of the mine.
In response to preliminary observations of crusher chamber deformation, additional ground support was designed and installed. As the rate of damage began to exceed the rate of rehabilitation, monitoring of rock mass became the predominant control to ensure that exposure to personnel working in the crusher chamber was appropriately safe. The intensity of the monitoring regime continued to increase as the rockmass deformed to the point that new laser scanning technology was implemented to provide short interval monitoring. Ultimately, the monitoring system enabled a safe and controlled closure of the chamber.
