Results 201 to 210 of about 7,051 (257)

Safety and Productivity in Underground Coal Mining

The Review of Economics and Statistics, 1983
An extended Cobb-Douglas production function is developed and estimated in order to examine the extent to which the decline in measured productivity in underground coal mining can be attributed to (1) changes in safety conditions which reflect movement along a product transformation frontier relating safety and marketable output and (2) a shift ...
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Particle Size Distributions in Underground Coal Mines

American Industrial Hygiene Association Journal, 1987
This paper reports the results of a sampling program undertaken by NIOSH to determine the particle size distributions in underground coal mines. The program made use of newly developed cascade impactors capable of being operated with personal sampling pumps.
J E, Burkhart, M A, McCawley, R W, Wheeler   +2 more
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Geotechnical Evaluation of the Support of Coal Pillars in Underground Coal Mines

Environmental & Engineering Geoscience, 1982
Failure of the mine floor supporting coal pillars frequently occurs when the subcoal strata include “underclays” or other low strength strata. The failure process has been studied to define the response of these materials to applied coal pillar loads and to determine the applicability of bearing capacity analysis to evaluate unsafe conditions.
J.D. Rockaway, R.W. Stephenson
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Underground lighting in coal mines

Proceedings of the IEE Part A: Power Engineering, 1956
The importance of lighting below ground is emphasized and the difficulties associated therewith are outlined. Inadequate or inferior lighting produces nystagmus, and mention is made of the decline in the incidence of new cases since better lighting has been introduced. Changes in portable lamps, with improvements in technique and to suit alterations in
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Floor design in underground coal mines

Rock Mechanics and Rock Engineering, 1989
Floor failure and excessive heave in underground coal mines can jeopardize the stability of the whole structure, including the roof and pillars, due to differential settlements and redistribution of stress concentrations. Besides, floor failure is detrimental to haulageway operation and can lead to unacceptable conditions of high deformation. Thus, the
C. Faria Santos, Z. T. Bieniawski
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Modeling of Underground Coal Mining Processes

Optoelectronics, Instrumentation and Data Processing, 2019
This paper presents a comprehensive simulation model of underground coal mining processes in a fully mechanized longwall mining face. A number of simulation experiments were performed. The face productivity is estimated as a function of various factors such as the technical parameters of mining machines, face length, gas factor, shearer operation mode,
V. V. Okolnishnikov, A. A. Ordin, S. V. Rudometov   +2 more
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Explosion hazards in underground coal mines

Toxicological & Environmental Chemistry, 1993
A review of the incidence, causes and prevention of coal dust explosions is given in this paper. A statistical summary of fire and explosion incidents in Nova Scotia coal mines over the last century is presented. Techniques for explosion prevention which are discussed include avoidance of ignition sources, use of ventilating air, and rock dusting ...
Paul R. Amyotte, Michael J. Pegg
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Time studies in underground coal mining

2012
Machine performance is the key to higher production and bigger profits in present day coal mining. By far the most important machine in a mechanized coal mining operation is the mobile loader. It must load the coal that pays for the entire operation, and its performance, therefore, is the deciding factor controlling success or failure of the mine ...
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Dust control in underground coal mining

2021
ÖZET Kömür ocaklarında mekanize üretim yöntemine hızla geçilmesi üretim miktarını arttırmakla birlikte hava içindeki solunabilir toz konsantrasyonunu da arttırmıştır. Ocak havasmdaki solunabilir toz konsantrasyonunu belirli sınırlarda tutmak için toz kontrolü yöntemlerinin iyi planlanması gerekir.
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UNDERGROUND MINING OPERATIONS IN ZONGULDAK COAL MINES

1966
The object of this article is to present all the aspects of underground mining activities in Zonguldak coal mines, the history of the mines, geological conditions, coal seam characteristics and general layout of the districts. Emphasis has been paid to mining methods, old and new, the available machinery and rates of output.
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