Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link


Centers for Disease Control and Prevention. CDC twenty four seven. Saving Lives, Protecting People
Search
            ×
                        Mining
                        Mining
                            NIOSH
                            All CDC
                    Submit
                For a full list of topics:A-Z Index
                Advanced Search
            Advanced Search


The National Institute for Occupational Safety and Health (NIOSH)





Mining Publication: A New Method to Calculate Permeability of Gob for Air Leakage Calculations and for Improvements in Methane Control
Keywords: Gobs Methane Numerical modeling
This page is archived for historical purposes and is no longer being maintained or updated.
Original creation date: June 2010
Authors: C� Karacan
Conference Paper - June 2010
Download PDF Document (0.17 MB)
NIOSHTIC2 Number: 20036993
Proceedings of the 13th U.S./North American Mine Ventilation Symposium, Sudbury, Ontario, Canada, June 13-16, 2010. Hardcastle, McKinnon, eds., Sudbury, Ontario, Canada: MIRARCO - Mining Innovation, 2010; :273-282
The porosity and permeability of the caved zone in a longwall operation impact many ventilation and methane control related issues, such as air leakage into the gob, the onset of spontaneous combustion, methane and air flow patterns in the gob, and the interaction of gob gas ventholes with the mining environment. Despite their importance, the gob is typically inaccessible for performing direct measurements of porosity and permeability. Thus, there has always been debate on the likely values of porosity and permeability of the caved zone and how these values can be predicted. This study demonstrates a fractal approach that allows the calculation of porosity and permeability from the size distribution of broken rock material in the gob, which can be determined from image analyses. The fractal approach presented here constructs flow equations and fractal crushing equations for granular materials to predict porosity for a completely fragmented porous medium. The virtual fragmented fractal porous medium so generated is exposed to various uniaxial stresses to simulate gob compaction and porosity and permeability changes during this process.
Image of publication A New Method to Calculate Permeability of Gob for Air Leakage Calculations and for Improvements in Methane ControlConference Paper - June 2010
Download PDF Document (0.17 MB)
NIOSHTIC2 Number: 20036993
Proceedings of the 13th U.S./North American Mine Ventilation Symposium, Sudbury, Ontario, Canada, June 13-16, 2010. Hardcastle, McKinnon, eds., Sudbury, Ontario, Canada: MIRARCO - Mining Innovation, 2010; :273-282
See Also
Computational Fluid Dynamics Modeling of Spontaneous Heating in Longwall Gob Areas
Control of Longwall Gob Gas With Cross-Measure Boreholes (Upper Kittanning Coalbed)
Degasification System Selection for U.S. Longwall Mines Using an Expert Classification System
Effect of Longwall Face Advance on Spontaneous Heating in Longwall Gob Areas
Methane Diffusion Parameters for Sized Coal Particles: A Measuring Apparatus and Some Preliminary Results
A Methodology for Determining Gob Permeability Distributions and its Application to Reservoir Modeling of Coal Mine Longwalls
A Numerical Evaluation on the Effects of Impermeable Faults on Degasification Efficiency and Methane Emissions During Underground Coal Mining
Probabilistic Modeling Using Bivariate Normal Distributions for Identification of Flow and Displacement Intervals in Longwall Overburden
Stochastic Modeling of Gob Gas Venthole Production Performances in Active and Completed Longwall Panels of Coal Mines
Underground Gob Gas Drainage During Longwall Mining
Page last reviewed: September 21, 2012
Page last updated: September 21, 2012
Content source: National Institute for Occupational Safety and Health, Mining Program
Facebook
        Twitter
        LinkedIn
        Syndicate Mining
        Site BrowserSafety and Health TopicsData & StatisticsMethodologyMine DisastersMSHA Data FilesMine & Mineworker ChartsTools & PublicationsTools You Can UsePublicationsNews & ArticlesResearch ProgramNORA Mining CouncilStrategic PlanMining Program, 2019-2023Miner Health Program, 2020-2030ProjectsContractsFunding OpportunitiesMining LinksAbout UsContact NIOSH MiningEmploymentFacilitiesHistoryVisitor Information NIOSH Homepage
 NIOSH A-Z
Workplace Safety & Health Topics
Publications and Products
Programs


About CDC
					Contact Us
					800-232-4636
 Facebook Twitter Instagram LinkedIn Youtube Pinterest Snapchat
 CONTACT CDC
				Contact Us
							Call 800-232-4636
							Email Us
			ABOUT CDC
				About CDC
							Jobs
							Funding
			POLICIES
				Accessibility
							External Links
							Privacy
							Policies
							No Fear Act
							FOIA
							OIG
							Nondiscrimination
							Vulnerability Disclosure Policy
			CONNECT WITH US
				Facebook
								Twitter
								Instagram
								LinkedIn
							Youtube
								Pinterest
								Snapchat
								Email
			LANGUAGES
				Español
							繁體中文
							Tiếng Việt
							한국어
							Tagalog
							Русский
							العربية
							Kreyòl Ayisyen
							Français
							Polski
							Português
							Italiano
							Deutsch
							日本語
							فارسی
							English


U.S. Department of Health & Human Services
			Accessibility
			External Links
			Privacy
			Policies
			No Fear Act
			FOIA
			Nondiscrimination
			OIG
			Vulnerability Disclosure Policy
			USA.gov


Exit Notification / Disclaimer Policy Close
 Links with this icon  indicate that you are leaving the CDC website. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website.
				Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website.
				You will be subject to the destination website's privacy policy when you follow the link.
				CDC is not responsible for Section 508 compliance (accessibility) on other federal or private website. Website Disclaimers
 Cancel Continue