Mining Project: Ventilation to Control Contaminants in Metal/NonMetal Mining Operations

Research Summary

This project enhanced worker health and safety in underground metal/nonmetal (M/NM) mines by improving the effectiveness of ventilation airflow, thereby limiting airborne contaminant (gases, DPM, and respirable dusts) concentrations to statutory levels or lower.

This project involved three research aims:

1. Determine appropriate strategies for booster fan use to increase the quality, quantity, and, hence, the effectiveness of ventilation airflow in both tabular and multi-level M/NM operations. Strategies include optimal location of the fan with respect to the face, minimally acceptable stopping designs to limit leakage between the booster fan and adjacent entry, timing for booster fan installation, and booster fan operational setting point determination.
2. Determine appropriate strategies for controlled district recirculation to improve ventilation effectiveness in both tabular and multi-level M/NM operations. Strategies include acceptable recirculation percentages as a function of inby contaminant levels, booster fan placement (in-line in the return airway or in a crosscut), minimum stopping or bulkhead design to limit airflow losses in the intake airway, and distance of recirculation sites from the active faces (for dilution of dusts and gaseous contaminants).
3. Determine if ion generation and filtration systems can be made a feasible methodology for removing airborne particulates (dust and DPM aerosols) from the ventilation airflow. Included will be designs for scaling-up smaller units, and best practices for using and locating these devices in M/NM operations.