This paper describes the ventilation analyses performed for the access tunnels at the New Level Mine project (NLMP) at Codelco’s El Teniente operation outside of Rancagua, Chile. This new mine is anticipated to reach a fi nal production of between 137 and 180 kt/d. Production from the NLMP is scheduled to start in the year 2017. The main access tunnels (MAT) are approximately 9 km in length,
with one for personnel and supply access and the second one for ore extraction through a conveyor system. These two tunnels are a critical component of the initial stage 1 development and will be constructed independently of the existing mine workings. The tunnels were originally designed to be constructed with two tunnel boring machines. However, later analyses changed the construction approach to a conventional drill and blast technique. Because the design included two mid-tunnel
ramp-to-surface connections, conventional mining methods would allow for development of the tunnels with multiple working faces to achieve a more rapid schedule. This paper presents the initial baseline considered for the ventilation design and the optimization methodology applied by Codelco to minimize the airflow and pressure requirements of the ventilation system. Modifications to the design resulted in the addition of strategic airways and raises that could provide a saving of approximately 1 MW, when compared to the original design.
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