The Mine Safety and Health Administration (MSHA) specification for rock dust used in underground coal mines, as defined by 30 CFR 75.2, requires 70% of the material to pass through a 200 mesh sieve (<75 µm). However, in a collection of rock dusts, 47% were found to not meet the criteria. Upon further investigation, it was determined that some of the samples did meet the specification, but were ...

British Columbia exports about 25 million tonnes per year of metallurgical coal from two coalfields, which follow the Rocky Mountains along the eastern edge of the Province. In the north there are two mines in the Peace River coal&Id and in the south, five mines in the east Kootenay coalfields (Figure I). The east Kootenay coalfields are divided into the Elk Valley, Crowsnest and Flathead field...

Jharia coalfield is one of the most important sources of coking coal in India. Coal mining activities in this coalfield have significantly caused mineralisation of surface and ground water; there-by adversely affecting it’s quality and utility. Several trace elements may be present in mine water released from various mining and processing operations. In this paper, an attempt has been made to a...

Based on the first National Study of Coal Workers' Pneumoconiosis (CWP) and the U.S. Geological Survey database of coal quality, we show that the prevalence of CWP in seven coal mine regions correlates with levels of bioavailable iron (BAI) in the coals from that particular region (correlation coefficient r = 0.94, p < 0.0015). CWP prevalence is also correlated with contents of pyritic sulfur (...

The United States has the world s largest coal reserves and Montana the highest potential for mega-mine development. Consequently, a large-scale effort to convert coal to liquids (CTL) has been proposed to create a major source of domestic transportation fuels from coal, and some prominent Montanans want to be at the center of that effort. We calculate that the energy efficiency of the best exi...

Coal mining is one of the most important causes of environmental pollution, as large quantities of coal dust particles are emitted. Colombia-South America has large natural coal reserves and "El Cerrejón" is the world's largest open-cast mine located in the northern department of Guajira. The aim of the present study was to evaluate genotoxic effects in a population exposed to coal residues fro...

Haul truck future TIMES have been hard for the major truck manufacturers with a number of major mining projects on hold, particularly pressurising the ultra-class market where the key contracts are relatively few and far between, compared to lower-capacity classes. The following details developments at Caterpillar and Liebherr, but also reveals for the first time BELAZ’s plans to roll out key m...

This paper studies the unstable mechanisms of the mechanical system that is composed of the stiff hosts (roof and floor) and the coal pillar using catastrophe theory. It is assumed that the roof is an elastic beam and the coal pillar is a strain-softening medium which can be described by the Weibull s distribution theory of strength. It is found that the instability leading to coal bump depends...

OBJECTIVE To investigate if blood Cu++/Zn++ superoxide dismutase, glutathione peroxidase, catalase, and total plasma antioxidant activities could be markers of biological activity resulting from exposure to respirable coal mine dust in active miners, and of pneumoconiosis in retired miners. METHODS Blood samples were randomly obtained from active surface workers (n = 30) and underground miner...

-. This roper discusses in *M tie process undetien to mitigate the effects of any fiture mine subsidence on prison structures proposed above old abandoned underground workings. The site for a proposed prison complex purchased by the State of Indiana was located in west-central Indiana and was undermined by an old abandoned room and pillar mine. The original plan for construcdon cmsisted of one ...