Acidity of water from abandoned underground mines decreases over time, and the rate of decrease can help formulate remediation approaches and treatment system designs. The objective of this study was to determine an overall acidity decay rate for above-drainage underground mines in northern West Virginia from a large data set of mines that were closed 50 to 70 yr ago. Water quality data were ob...

Past efforts to estimate methane emissions from underground mines, surface mines, and other coal mine operations have been hampered, to different degrees, by a lack of direct emissions data. Direct measurements have been completely unavailable for several important coal mining operations. A primary goal of this study was to collect new methane emissions measurements and other data for the most ...

The influence of the coal mine geographical environment on the electromagnetic transmission might result in the difficulty of wireless positioning under the mine. Concerning that the influence of the underground working face on the wireless signal attenuation is mainly reflected on the path attenuated electricity and based on the underground geographical differences, two corresponding electroma...

For several years, our research group has been developing methods for automated modeling of 3D environments. In September, 2002, we were given the opportunity to demonstrate our mapping capability in an underground coal mine. The opportunity arose as a result of the Quecreek mine accident, in which an inaccurate map caused miners to breach an abandoned, water-filled mine, trapping them for seve...

The increases above 1975 levels for acid mine drainage and subsidence for the years 1985 and 2000 based on projections of current mining trends and the National Energy Plan are presented. No increases are projected for acid mine drainage from surface mines or waste since enforcement under present laws should control this problem. The increase in acid mine drainage from underground mines is proj...

The current s t a t e of the a r t of f i r e and smoke detect ion technology i s reviewed from the standpoint of s u i t a b i l i t y f o r use i n underground metal and nonmetal mines. Detection modes, f i r e signatures, and environmental considerat ions a r e included. Preliminary r e s u l t s of longterm, in-mine t e s t s a r e presented.

Fire experiments were conducted in the Safety Research Coal Mine (SRCM) at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, with coal, diesel-fuel, electricalcable, conveyor-belt, and metal-cutting fire sources to determine the response of fire sensors to productsof-combustion (POC). Metal oxide semiconductor (MOS) and smoke fire sensors demonstrated an...

The Boundary Element Method has been applied to calculate stress distribution and stability of underground mines for disposal of chemical waste. A case similar to the Stripa mine in Sweden has been considered. The rock mass was granite, with major fracture zones represented by three families of planes mutually orthogonal and 100 meters distant from each other. The pre and post processor GiD [3]...

To overcome the frequency-selective fading of ultra wide band (UWB) caused by the multi-path propagation in complicated environment of coal mines, an underground wireless communication system of UWB based on multi-band orthogonal frequency division multiplexing (MB-OFDM) for coal mine is presented. Independent angle impulse response is used to build up revised channel model for underground tunn...

The Giant Mine, located in Yellowknife, Northwest Territories, Canada has been operating as a gold mine since 1948. Giant has been primarily an underground operation which used roaster technology to remove of gold from refractory arsenopyrite ore. The roasting process produced arsenic trioxide bearing dust as a waste product. This dust was pneumatically conveyed into underground storage chamber...