In mining of inclined coal seams in Tangshan coal mine of Kailuan group, gateways on either end of a panel were both typically located along the floor and a gateway pillar between adjoining panels was left unmined between adjacent panels to ensure stability, thus forming a planar mining system. According to the practice, however, it turned out that this conventional mining system has long-stand...

A longwall water jet mining machine called the Hydrominer has been developed at the University of Missouri-Rolla under a Bureau of Mines contract. The first design, referred to as Hydrominer One, has been extensively tested in an open pit mine and has clearly demonstrated that the working principle is viable. The second and greatly improved version, Hydrominer Two, has been built but has not as...

Received signal strength-based positioning and tracking of humans is a reliable solution for harsh indoor environments like the longwall tunnels at underground coal mining sites. The mining personnel with radio tags on their body can be tracked along a line of sensing reference nodes. The wired bus backbone for the transmission of all sensor data to a central processing station is the limiting ...

Large-scale longwall mining of shallow coal seams may cause mining-induced fractures that can project completely through to the surface. This could lead to a series of mine safety and environmental issues, further deteriorating the already fragile ecological environment in the Western mining areas in China. Therefore, an accurate and effective understanding of the spatiotemporal evolution law o...

Reduction in the recovery time required and improvements in safety during a longwall face move have compelled coal mine operators to examine and use predriven longwall recovery rooms. The recovery entry is developed at the longwall stop position and supported ahead of time so that the required combinations of standing and internal supports can be installed before the longwall face approaches. A...

Nowadays we can observe the change of the structure of energy resources, which leads to the increasing fraction of a renewable energy sources. Traditional underground coal mining loses its significance in a total but there are countries, including Poland, which economy is still coal based. A decreasing coal resources imply an exploitation a becoming harder accessible coal beds what is connected...

In 1991 the Mine Safety and Health Administration conducted a special program to assess occupational exposures to respirable coal mine dust in underground coal mines. Priority was given to longwall mining operations, mines with a history ofhaving a problem controlling dust to the applicable standard, and a representative number of all other mines. Measurements were obtained on approximately 720...