دانلود کتاب Guidelines for the Prediction and Control of Methane Emissions on Longwalls

Compiled by the U.S. Dept of Health and Human Services, CDC/NIOSH Office of Mine Safety and Health Research, these 2008 guidelines are recommended for controlling longwall coalbed methane. Although longwall mining productivity can far exceed that of room-and-pillar mining, the total methane emissions per extracted volume associated with longwall sections are generally higher than those for continuous miner or pillar removal sections. Increased face advance rates, increased productivities, increased panel sizes, and more extensive gate road developments have challenged existing designs for controlling methane on longwalls. Methane control research by the National Institute for Occupational Safety and Health (NIOSH) recently examined a number of practices designed to maintain concentrations in mine air within statutory limits and consistently below the lower explosive limit. All predictions are based on determinations made for the Pittsburgh Coalbed in southwestern Pennsylvania. Content: Front Matter • List of Illustrations • List of Tables • Acronyms and Abbreviations Used in This Report • Unit of Measure Abbreviations Used in This Report • Table of Contents • Executive Summary 1. Reservoir Modeling for Predicting Methane Emissions in Development Headings (Entries) 2. Controlling Longwall Face Methane and Development Mining Emissions: Predicted Improvements Using In-Seam Boreholes 3. Characterizing and Forecasting Longwall Face Methane Emission Rates for Longer Longwall Faces 4. Predicting Methane Emissions from Longer Longwall Faces by Analysis of Emission Contributors 5. Development of Numerical Models to Investigate Permeability Changes, Distributions, and Gas Emissions around a Longwall Panel 6. Methane Emission Control during Mining of Longwall Panels Using Gob Gas Ventholes 7. The Application of Gob Gas Ventholes to Control Methane in Wider Longwall Panels and Gobs 8. Induced Fracturing and Coalbed Gas Migration in Longwall Panel Overburden: The NIOSH Borehole Monitoring Experiment • Practical Guidelines for Controlling Longwall Coalbed Methane • References