Mining Publication: Benchmarking Longwall Dust Control Technology and Practices
Significant advances in longwall mining technology and equipment have occurred over the last decade. By the late 1990s, longwall mine output accounted for 40% of all underground output in the U.S. and today longwall mines account for approximately 50% of coal produced underground in the United States. A 51% increase in average shift production rates has occurred over the last 15 years. This increased longwall productivity has meant that far more dust is being produced and controlling respirable coal dust presents an ongoing challenge for coal mine operators. The National Institute for Occupational Safety and Health (NIOSH) conducted a series of benchmark surveys at longwall operations across the country to identify current operating practices and the types of controls being used. Gravimetric and instantaneous dust sampling was completed to quantify the dust levels generated by major sources on the longwall section and to identify different control technologies in use today. Substantial reductions in dust levels were realized at sampling locations on the face when compared with longwall surveys conducted in the 1990s. Results from the underground dust surveys and current longwall dust control technology and operating practices will be discussed.