A pair of research teams from West Virginia University have received close to $500,000 in funding from the Alpha Foundation for the Improvement of Mine Safety and Health.
The first team, led by Derek Johnson, associate professor of mechanical and aerospace engineering, will look at cost-effective ways to measure methane in longwall coal mining operations in hopes of preventing the most feared hazards in underground coal mines: methane and dust explosions. Joining Johnson on the team are Nigel Clark, George B. Berry Chair of Engineering and professor of mechanical and aerospace engineering, Yi Luo, associate professor of mining engineering, and Mark Sindelar, research assistant professor of mining engineering.
Their proposed methane watchdog system will deploy a low-cost, multi-nodal methane measurement network that will monitor methane concentrations and velocity continuously along the full length of the longwall face.
The system will measure, record and report on discrete methane concentrations in nearly real time, along the front and rear ends of the canopy of the supports or shields.
“The measured methane concentration distribution can be used as an algorithm input to decide whether the shearer should be de-energized before advancing into potentially explosive methane-air pockets,” Johnson said. “The methane concentration distribution along the rear end of the shield canopy will enable the development of an improved bleeder ventilation plan.
“This strategy,” Johnson added, “will ensure the front edge of the explosive methane zone in the gob area, especially near the face/tailgate corner, will remain sufficiently far from longwall face while reducing the likelihood of over-ventilating the gob to prevent spontaneous combustion.” The gob is the void from which all the coal in a seam has been extracted and where the roof is allowed to collapse in a controlled manner.
The team will then combine the methane measurements with shearer location and ventilation flow rates along the wall face to estimate the methane liberation rates from the coal seam ahead of the shearer and from longwall gob.
“The ability to accurately collect, record and analyze methane concentrations at multiple locations will immediately improve mine safety and will ultimately lead to better models and design methods to prevent methane and dust explosions,” Johnson said.
The second team, led by Ihsan Berk Tulu, assistant professor of mining engineering, will look at ways to reduce ground control-related injuries and fatalities in the mining industry by developing a practical, mechanics-based approach to pillar design.
The research team, which includes Brijes Mishra, associate professor of mining engineering and graduate research assistant Deniz Tuncay, will work to develop a geology-based laminated overburden model.
“The recent Analysis of Retreat Mining Pillar Stability LaModel program – or ARMPS-LAM – which was developed at WVU, was an initial step toward incorporating mechanistic overburden behavior into pillar design,” said Tulu. “We will build upon previous WVU research and incorporate the specific geology and structural competence of the overburden and the in-situ horizontal stresses into the mechanical response of the overburden.”
Tulu noted that this new mechanistic mode will be an important step toward reducing the risk factors for the underground mine workers by further understanding the role of the overburden mechanics in pillar design, thereby improving mine stability.
Ground control-related incidents are still one of the leading injury and fatality reason in underground coal mines. According to statistics from the Mine Safety and Health Administration, there were 35,228 underground coal mine workers in 2015 working either in a longwall or retreat-room-and-pillar mine. Between 2011 and 2015, there were 1,037 nonfatal lost-time ground control-related injuries and from 2014 to 2017, 20 percent of the all the fatalities were ground control related.
The Alpha Foundation for the Improvement of Mine Safety and Health is a private foundation with the mission to improve mine safety and health through funding research and development projects at qualified academic institutions and other not-for-profit organizations.