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Presentation on the re-opening of the mines under new DPM regulations, including site overview, plans, ventilation design, and recommendations.
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Old Mines - New Regulations The Re-opening of the Gordonsville, Elmwood, and Cumberland Mines Under New DPM Regulations 12th U.S./North American Mine Ventilation Symposium June 9-11, 2008 Reno, Nevada USA Presented by: Albert Adu-Acheampong Susan Patton AGAPITO ASSOCIATES, INC. Mining & Civil Engineers & Geologists
Presentation Outline • Site Overview and Background • Previous Work by Agapito Associates, Inc. (AAI) • Future Mining Plans • Basis for the Analysis • Ventilation System Design • Recommendations • Startup Issues
Site Overview 72 km (45 miles) East of Nashville
Site Overview and Background The Gordonsville, Elmwood (GV/E) and Cumberland Mines were formerly owned by Pasminco The mines were last operated in 2003 and were decommissioned Currently owned by Strategic Resource Acquisition (SRA) and operated by Dynatec. The mines utilize a random room-and-pillar mining method to extract zinc underground
Previous Work by AAI Pressure/quantity survey in 1996 for Savage Zinc, Inc. Developed and validated a computer network model for the mine
Basis for the Analysis • 1996 pressure/quantity survey data • Site Visit • Information Received from Client • Equipment selection table with utilization • Production sequence with mine map • Power cost • Ventilation System Constraints • Fans limited to less than 300 BHP • Decline on intake air • Plans to bore two new 3.7m (12 ft) diameter vent raises
Ventilation System Design – Quantity Estimation • DPM • New DPM exposure limit of 160TC µg/m3 • Equipment approved by MSHA has a nameplate with two pieces of information: • (a) Particulate Index (PI)—Dilution air required to reduce the exhaust total DPM concentration to 1000 µg/m3 (total carbon content 80%) • (b) gaseous ventilation rate
Ventilation System Design – Quantity Estimation • DPM • Sum of PI for the equipment specified for GV/E=115.89 m3/s (245,550 cfm) • Sum of PI for the equipment specified for the Cumberland Mine=11.7 m3/s (23,650 cfm) • By ratio ({800*PI}/Exposure Limit) equates to total volume of air required of 613.53 m3/s (1.3 million cfm) and 58.5 m3/s (118,250 cfm)
Ventilation System Design – Analysis and Results • Based on the quantity required • Eight scenarios were analyzed for the GV/E Mine Complex • The GV/E Mine Complex required 5 intakes and 7 exhausts
Ventilation System Design – Analysis and Results • Based on the quantity required • Three scenarios were analyzed for the Cumberland Mine • The Cumberland Mine required 2 intakes and 2 exhausts
Ventilation System Design Recommendations • Startup settings • Continued monitoring • Practice contaminant monitoring • Ventilation surveys recommended to correlate models
Mine Ventilation Startup Issues • Auxiliary system capacity • Existing raises • Managing equipment locations to limit exposures • Rehabilitating shafts and raises • Dewatering
Acknowledgements The authors would like to thank SRA and Dynatec for initiating this project
Questions ??? Albert Adu-Acheampong 715 Horizon Dr. Ste 340 Grand Junction, CO 81504 Tel: 970 254-9392 Email: aaadu@agapito.com