BACKGROUND Particulate exposure from air pollution increases the risk of ischemic heart disease (IHD) mortality. Although coal miners are highly exposed to coal dust particulate, studies of IHD mortality risk among coal miners have had inconsistent results. Previous studies may have been biased by the healthy worker effect. METHODS We examined the dose-response relationship between cumulative...

There are many coal seams in high-gas mining area of China. The permeability is low. The gas extraction from the original coal seam is difficult and the commercial value is little. The conception of the safe high-efficient exploitation of coal and gas is put forward in this article. It changes the conventional exploitation sequence that is from the upper to below. When we exploit coal seams, th...

Pulverized Wyoming subbituminous coal was beneficiated by low-pH oil agglomerationat CONSOL to prepare the coal for direct liquefaction. Conventional cleaning is not veryeffective in cleaning this coal; for example, conventional oil agglomeration only givesabout 20% ash rejection. To improve ash rejection, the coal-water slurry was acidifiedto a pH of about 0.5. Oil agglomeratio...

OBJECTIVE To estimate the risk of lung cancer associated with the use of different types of coal for household cooking and heating. SETTING Xuanwei County, Yunnan Province, China. DESIGN Retrospective cohort study (follow-up 1976-96) comparing mortality from lung cancer between lifelong users of "smoky coal" (bituminous) and "smokeless coal" (anthracite). PARTICIPANTS 27,310 individuals u...

Investigations were carried out on coal tailings by conventional cell and column flotation techniques. Tests were conducted to assess processing coal tailings of Alborz Markazi coal washing plant in Iran by column flotation. The effects of reagent type/dosage were investigated with conventional flotation and their results were used in the performance of column flotation. Also the effects of the...

In this study, various organic solvents were used to prepare coal slurries and the rheological and thermal properties of coal-organic solvent slurries were examined. Solvents with molecules containing unpaired electrons (high basicity) show high extraction power and cause swelling of coal. Therefore, coal-organic solvent slurries usually showed higher viscosities compared to coal-water slurry. ...

In order to achieve high performance and efficiency of coal-fired power plants, it is highly important to control the coal flow into the boiler in the power plant. This means suppression of disturbances and force the coal mill to deliver the required coal flow, as well as monitor the coal mill in order to detect faults in the coal mill when they emerge. This paper deals with the second objectiv...

Coal is a combustible material applicable to a variety of oxidation scenarios with conditions ranging from atmospheric temperature to ignition temperature. One of the most frequent and serious causes of coal fires is self-heating or spontaneous combustion. Opening an underground coal seam to mine ventilation air, such as long-wall gob and goaf areas and coal stockpiles, creates a risk of sponta...

China has considerable coal resources. Benefiting from the widespread distribution of coal measures and the inter-sedimentary development of coal bed, dark shale, and fine-grained tight sandstone in coal measures, China has a geological environment and material basis favorable for the co-occurrence of a variety of coal gases. With such a huge reservoir of coal gases, including gases such as coa...

differential scanning calorimetry (dsc), temperature programmed desorption mass spectrometry (tpd-ms) and small angle neutron scattering (sans) were used to investigate co2 uptake by the wyodak coal. adsorption of carbon dioxide on wyodak coal was studied by dsc. the exotherms evident at low temperatures are associated with the uptake of co2 suggesting that carbon dioxide interacts strongly wit...