Mining Project: Respirable Dust Control for Surface Mines

Research Summary

This research project aimed to reduce silica exposure in surface mine workers by developing dust control techniques that could reduce dust generation from the drilling and hauling operations. Haul road testing provided information to develop new controls or reinforce existing dust control methods for mine haul roads. A Helmet-CAM task, which involved video dust sampling of mobile workers at the mine site, along with a software analysis of the dust exposure videos, allowed researchers to develop successful dust control techniques for occupations such as laborers, mechanics, welders, etc. Computational fluid dynamics (CFD) were used to identify problematic areas and aid in the development of successful dust controls by allowing simulations at lab facilities. Researchers demonstrated improved dust control technologies at a limited number of mining operations. However, this technology will have application throughout the surface mining industry, as well as the construction and agriculture industries where similar equipment and occupations occur.

This project had four research aims, as follows:

1. Horizontal air-blocking shelf testing was completed, and NIOSH released publications detailing results (FY2010–FY2011).
2. In collaboration with CAT and an operating mine site, researchers completed haul road testing for a new water delivery system (WDS) developed by CAT. An analysis of results finalized the hauling task.
3. The Helmet-CAM test progressed with the development of the EVADE (Enhanced Video Analysis of Dust Exposures) software in FY2011. Using the Helmet CAM technology, video monitoring and dust sampling techniques were tested on selected mobile worker occupations at surface mines (FY2010–FY2012). Work conducted in FY2010 and FY2011 was used to analyze Helmet-CAM data and to investigate potential improvements to the dust sampling methods and the EVADE software, which were finalized in FY2012. Other sites were tested in late FY2011 and into FY2012 to develop cross-cutting dust controls for the entire mining industry. Researchers completed Helmet-CAM testing and respirable dust source identification for the blast crews at several mine sites. The development and establishment of the video monitoring and dust sampling techniques used for Helmet-CAM, the development and debugging of the EVADE software, and the successful testing and identification of respirable dust sources conducted at various mine sites for blast crews concluded this task.
4. A computational fluid dynamics (CFD) specialist was hired to improve the CFD task schedule. Analysis of the longwall miner, continuous miner, and drill shroud labs progressed and continued through FY2012. In-house airflow analysis was conducted to aid in the improvement and development of dust controls for the continuous miner, with significant work being conducted to model and validate different continuous miner configurations. The introduction of dust particles began during FY2010 and continued through FY2012. The CFD task for this project concluded with the establishment of a functioning CFD modeling/simulation capability at NIOSH. However, CFD is a continuous process, and tasks will be continued under future projects.

At the completion of this project, current dust control technologies were improved and new controls had been developed for the drilling, hauling, and labor-intensive operations at a surface mine site.