Shock losses characterization of ventilation circuits for block caving production levels

• Block caving ventilation: usually shock loss values taken from piping and HVAC tables.
• Circuit ventilation: very tortuous, which generates significant shock losses.
• Geometry studied: based on the El Teniente (Chile) mine layout.
• Methodology: validation of experimental and numerical scale model and real model.
• Objective: determine energy losses and improve geometries to diminish energy consumption.

With the tendency of world ore deposits to be deeper and of lower grade, block caving is becoming an increasingly important mining method. As with any underground method, an adequate mine ventilation system is essential to control operational costs while achieving the development and production schedule. This paper presents results obtained from a simulation based on Computational Fluid Dynamics (CFD), in combination with a mine ventilation network solver, to determine the head losses for the ventilation circuits of the production level drifts within the block caving layout at the El Teniente mine. In order to simulate the ventilation network, the airflow path is characterized in terms of shock losses from the intake ventilation sublevel through the drifts to the exhaust ventilation sublevel. Subsequently, these simulated head losses are used for the ventilation model of the drift and solved using a commercial ventilation program, to assess the energy loss. Simple energy saving modifications can then be proposed, generating 25% savings. This methodology assists in the design of production levels having efficient mine ventilation systems.