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Results 51 - 60 of 111
2/1/2000 - Conference papersA paper describing research at a Pittsburgh Coalbed longwall mine to evaluate and optimize bleeder ventilation and gob gas venthole longwall methane control systems.
Prediction of Longwall Methane Emissions: An Evaluation of the Influence of Mining Practices on Gas Emissions and Methane Control Systems10/1/1999 - Reports of InvestigationsAn analysis of the consequences of increasing longwall panel dimensions, particularly face width, in gassy coalbeds. Continuous longwall face emission monitoring studies were conducted at two adjacent mines operating in the Pocahontas No. 3 Coalbed, whe...
5/1/1999 - Conference papersInvestigation of the geologic and mining factors influencing the migration of longwall gob gas with a goal to optimize methane drainage strategies to reduce the volume of gob gas that reaches the underground workplace.
3/1/1995 - Technology NewsThe absence of fundamental scientific and engineering principles in the design and placement of gob gas ventholes can cause difficulties for mine operators when gas emissions increase because of a change in mine design or because variable geologic condi...
1/1/1994 - Information CircularsThe U.S. Bureau of Mines conducted a worldwide literature review of bleederless ventilation practices to evaluate their use as a spontaneous combustion control measure in U.S. coal mines. This report describes the types of ventilation systems used throu...
1/1/1992 - Reports of InvestigationsFour coreholes were drilled at a longwall mine in the Lower Kittanning coalbed to obtain coal and rock samples from overlying strata to determine their gas content during the mining cycle. Test results indicate that 91% of the gas came from coalbeds.
1/1/1990 - Reports of InvestigationsThe Bureau of Mines preproduction wireless survey system (WSS) and its performance during an in-mine test are discussed in this report. The WSS was developed to reduce downhole surveying time in order to increase the efficiency of drilling long horizont...
1/1/1989 - Reports of InvestigationsThe U.S. Bureau of Mines used a contact drilling strategy with short-collared assemblies in order to rotary drill long horizontal methane drainage holes in the Beckley coalbed near Glen Daniel, West Virginia. By decreasing the thrust and increasing the ...
1/1/1988 - Reports of InvestigationsThe Bureau of Mines conducted an investigation into the occurrence of outbursts of salt known to be responsible for explosions, fatalities, and damage in domal salt mines. The purpose of the investigation was to develop a basis for predicting these outb...
1/1/1987 - Reports of InvestigationsGob holes are routinely used by the mining industry to vent methane from gobs and to prevent it from entering the mine ventilation system. In some cases, flows from gob holes are measured by centering an anemometer on the end of a discharge pipe. These ...