Mining Project: Smart Ventilation to Control Airborne Pollutants and Physical Stressors in Underground Metal/Nonmetal Mines

Research Summary

Mine operators continue to expand production in underground mines by employing larger diesel-powered equipment in greater numbers and by mining into hotter and more challenging areas further away from fresh air sources. These conditions continually challenge the ability of the ventilation system to provide adequate quantities of fresh air to cool and dilute air in the mine. This has resulted in increased airborne contamination and physical stressors that threaten the health and safety of miners.

Sophisticated ventilation engineering is an important component to providing underground miners with a safe work environment under these increasingly more demanding conditions. Ventilation-on-demand (VOD) technology has been applied on mine-wide scales that can make ventilation changes on a macro-scale, but VOD systems have limited provisions for localized, short-term contaminant control, especially when hazardous conditions are fluctuating over relatively short time periods. Research was required in order to investigate the efficacy of monitoring and control systems that can identify and measure localized health and safety hazards and implement engineering controls or modify localized ventilation in order to mitigate the hazards.

For metal/nonmetal mines in particular, ventilation air often passes through multiple work areas in series and contaminant concentrations can accumulate, reaching levels near or above Mine Safety and Health Administration (MSHA) air quality limits. Additionally, contaminants such as DPM and dust are examples of airborne hazards that can be present in concentrations that are often intermittently high, and localized to one part of the mine. Changes to the overall mine ventilation system do not effectively address these transient overexposures because of the time it takes for changes in air flow to reach the affected area and the possible negative effects that could occur to the air flow in other parts of the mine.

To address these issues, this project had three research aims, as follows:

1. To evaluate potential monitoring solutions by conducting a technology search to determine the availability of appropriate monitoring technologies, including studies of mining and other industrial data management and control systems.
2. To identify and select appropriate engineering controls to reduce diesel particulate matter (DPM) and dust in-situ in an underground mine.
3. To build and test a monitoring and control system (MCS) that targets the reduction of localized transient exposures to a hazard.

This project research aimed to demonstrate the efficacy of using real-time monitoring technologies in concert with engineering controls or other air-quality improvement schemes in order to mitigate workers’ potential overexposure to such localized or transient hazards. This two-year project developed, implemented, and evaluated autonomous MCSs that interface with engineering controls to minimize high-level transient DPM and respirable dust exposures in a laboratory environment to develop a system for installation in underground mines. Successful completion of this research and its associated publications led to adoption of newly developed MCSs and interventions for DPM, which lowered exposure levels, and if applied to underground mining work areas, will reduce the incidence of respirable diseases in the metal/nonmetal mining industry.