Causation mechanism of coal miners' human errors in the perspective of life events

In order to effectively decrease the safety accidents caused by coal miners’human errors,this paper probes into the causality between human errors and life events,coping,psychological stress,psychological function,physiological function based on life events’vital influence on human errors,establishing causation mechanism model of coal miners’human errors in the perspective of life events by the researching method of structural equation.The research findings show that life events have significantly positive influence on human errors,with a influential effect value of 0.7945 and a influential effect path of‘‘life events—psychological stress—psychological function—physiological function—human errors’’and‘‘life events—psychological stress—physiological function—human errors’’.

Lead Exposure and Oxidative Stress in Coal Miners

We aimed to investigate the short-term correlation between blood lead levels and oxidative stress generation in coal miners. The study involved 94 male coal miners from the Velenje Coal mine, arranged into four groups： three groups according to the number of consecutive working days, and a fourth control group. Miners who worked for three consecutive days had higher blood levels of lead and 8-isoprostane than the control group（P 〈 0.001）. Correlation between lead and 8-isoprostane was of medium strength（r = 0.512, P 〈 0.001）. Short-term lead environmental exposure can potentially harmful and should be considered when formulating improvements in working processes.

Expression of Hsp27 and Hsp70 in Lymphocytes and Plasma in Healthy Workers and Coal Miners with Lung Cancer

In coal mines, main occupational hazard is coal-mine dust, which can cause health problem including coal workers’ pneumoconiosis and lung cancer. Some heat shock proteins (Hsps) have been reported as an acute response to a wide variety of stressful stimuli. Whether Hsps protect against chronic environmental coal-mine dust over years is unknown. It is also interesting to know that whether the expression of Hsp27 and Hsp70 proteins as a marker for exposure is associated risk of lung cancer among coal miners. We investigated the association between levels of Hsp27 and Hsp70 expression in lymphocytes and plasma and levels of coal-mine dust exposure in workplace or risk of lung cancer in 42 cancer-free non-coal miners, 99 cancer-free coal miners and 51 coal miners with lung cancer in Taiyuan city in China. The results showed that plasma Hsp27 levels were increased in coal miners compared to non-coal miners (P<0.01). Except high cumulative coal-mine dust exposure (OR=13.62, 95%CI=6.05—30.69) and amount of smoking higher than 24 pack-year (OR=2.72, 95% CI=1.37—5.42), the elevated levels of plasma Hsp70 (OR=13.00, 95% CI=5.14—32.91) and plasma Hsp27 (OR=2.97, 95% CI=1.40—6.32) and decreased expression of Hsp70 in lymphocytes (OR=2.36, 95% CI=1.05—5.31) were associated with increased risk of lung cancer. These findings suggest that plasma Hsp27 may be a potential marker for coal-mine dust exposure. And the expression of Hsp27 and Hsp70 levels in plasma and lymphocytes may be used as biomarkers for lung cancer induced by occupational coal-mine dust exposure.

Optimization design of drilling string by screw coal miner based on ant colony algorithm

It took that the weight minimum and drive efficiency maximal were as double optimizing target,the optimization model had built the drilling string,and the optimization solution was used of the ant colony algorithm to find in progress.Adopted a two-layer search of the continuous space ant colony algorithm with overlapping or variation global ant search operation strategy and conjugated gradient partial ant search operation strat- egy.The experiment indicates that the spiral drill weight reduces 16.77% and transports the efficiency enhance 7.05% through the optimization design,the ant colony algorithm application on the spiral drill optimized design has provided the basis for the system re- search screw coal mine machine.

Composition and mode of occurrence of minerals in Late Permian coals from Zhenxiong County,northeastern Yunnan,China

Minerals in the Late Permian coals from the Niuchang-Yigu mining area,Zhenxiong County,northeastern Yunnan,China,were investigated using optical microscopy and low temperature ashing plus X-ray diffraction(LTA?XRD).The results showed that minerals in the coal LTAs are mainly quartz,kaolinite,chamosite,mixed-layer illite/smectite(I/S),pyrite,and calcite,with trace amounts of marcasite,dolomite,and bassanite.The authigenic quartz generally occurs in collodetrinite or as a filling in cleats or cell cavities.This silica was mainly derived from aqueous solutions produced by the weathering of basaltic rocks in the Kangdian Upland and from hydrothermal fluids.The presence of b-quartz paramorph grains in collodetrinite probably indicates that these grains were detrital and came from a volcanic ash.Clay minerals are generally embedded in collodetrinite and occur as cell-fillings.Pyrite occurs as framboidal,anhedral,and euhedral grains and a cell-filling.The coals are high in pyrite and the high pyrite content probably results from seawater invading during the stage of peat accumulation.Calcite generally occurs as vein-fillings,indicating an epigenetic origin.

Transformation of inherent and extraneous minerals in feed coals of commercial power stations and their density-separated fractions

The main objective of this work is to relate the coalescence of inherent minerals and the fragmentation of extraneous minerals to the slagging propensities of South African pulverised feed coals during combustion.By incorporating the behaviour of inherent mineral matter or extraneous mineral matter in these coals under combustion conditions into ash-deposition prediction methods,the heterogeneous nature of the ash properties,which were disregarded in previous conventional ash deposition predictions,is considered in the study.The mode of occurrence of mineral matter in feed coals plays a crucial role in the formation of high-temperature mineral phases under combustion conditions.The float and sink fractions of the three different coals evaluated in this distinctive alternative approach provide different chemical and mineralogical properties of the derived ashes when subjected to elevated temperatures under oxidising conditions.Formation of significant concentrations of high-temperature minerals(such as mullite and cristobalite)is mainly due to the transformation reactions of extraneous kaolinite and quartz which are not associated with the extraneous fluxing minerals at elevated temperatures.However,the formation of anorthite at elevated temperatures can be attributed to the interaction of either inherent or extraneous fluxing minerals(namely calcite,dolomite,pyrite,and siderite)that are associated with either inherent or extraneous kaolinite in the coal samples under the oxidising condition.Furthermore,the anorthite,mullite,and calcium/magnesium/iron/aluminosilicate and silica glasses in ashes are formed either via crystallisation during the cooling of the hightemperature molten solution or via the solid state reactions.These high-temperature minerals and their glasses present in ashes can therefore be used as the indicators of the slagging propensity of coals.The implementation of results from this unique case study,will be of great significance to other industrial combustion processes to minimise or control ash deposition,slagging,and equipment erosion problems by either blending the density-separated fractions of coals or coals from different mines based on the chemical and mineralogical properties to prepare suitable feed coals.Furthermore,this unique alternative approach can be followed to further evaluate other feed coals in the global power stations during combustion.

CO_2 –H_2O–coal interaction of CO_2 storage in coal beds

In order to study the physical and chemical reaction after CO2 injected into coal beds at different condition.The physical and chemistry reaction among CO2,H2O and coal was studied,and the influence on permeability and porosity of coal beds was carried out.The experimental method was used,so did the basic theory of mineralogy,coal petrology,geochemistry,analytical geochemistry and physical chemistry.In this experiment,the changes of mineral and permeability of coal and water quality were observed through CO2 solution reacting with different coal samples.The differences could be found out by comparing the properties and microcrystalline structure before and after the reaction.There are three results were carried out:First,the content of carbonate in coal beds decreases because of the dissolution reaction between carbonate minerals and CO2 solution,and precipitation is formed by reaction of chlorite and orthoclase.Second,the result that permeability and porosity of coal beds are improved after the reaction is proposed.Third,the initial permeability of different coal samples plays a great role on the reaction,and the improvement of permeability is not obvious in the samples which have too low or too high permeability,and the improvement is good in medium permeability(0.2–3 mD).

Geochemistry of Mercury in the Permian Tectonically Deformed Coals from Peigou Mine, Xinmi Coalfield, China

As the mercury emitted from coal combustion can lead to serious environmental issues, researchers pay more attention to the content, distribution and occurrence of mercury in coal. In this paper, the content, distribution, and occurrence of mercury in the Permian tectonically deformed coals from Peigou Mine, Xinmi coalfield, Henan Province were investigated. A total of 18 bench samples were taken from No.2-1 coals seam in Peigou Mine, including 15 coal bench samples, two roofs and one floor. The mercury concentration, mineral composition, and main inorganic element content of 18 samples were determined by DMA-80 direct mercury analyzer, XRD, and XRF respectively. The results show that the mercury content ranges from 0.047 ppm to 0.643 ppm, with an average of 0.244 ppm. Though the coal seam has turned into typical tectonically deformed coal by the strong tectonic destruction and plastic deformation, the vertical distribution of mercury has remarkable heterogeneity in coal seam section. By the analysis of correlation between mercury and the main inorganic elements and the mineral composition in coal, we infer that majority of mercury mainly relates to pyrite or kaolinite.