Effects Of Coal Dust Research Articles

Глобальная горная промышленность в 2018 году и перспективы ее развития

Глобальная горная промышленность в 2018 году и перспективы ее развития

Effect of coal dust on the air-methane mixture combustion in the Swiss-roll burner

The 2-D numerical model has been developed to simulate the combustion of lean coal-methane-air mixture in ?Swiss-roll? burner and investigate the effect of coal particles content and mixture feed rate on the stable burner operation. Five homogeneous and three heterogeneous chemical reactions are considered. The Eulerian model for gas phase and the discrete particle model (Lagrangian) for particle phase taking into account the radiation are used in this study. Simulations are performed for the two turns ?Swiss roll? burner with heat insulated outer wall, channel width of 6 mm and inner wall thickness of 2 mm. It is shown that the presence of coal particles in a lean methane-air mixture expands the range of stable operation of the "Swiss-roll" burner. It is found that an increase in the content of coal particles reduces the combustion time of the particles by in-creasing the combustion temperature, changes the shape of the reaction zone, and shifts it to the burner inlet.

Prediction of dust particle size effect on efficiency of photovoltaic modules with ANFIS: An experimental study in Aegean region, Turkey

In this study, the effect of coal dust in variable sizes and weight on photovoltaic (PV) modules' performance has been examined under laboratory conditions. Experimental studies have been performed under Standard Test Conditions (STC: Radiance: 1000 W/m2; Cell temperature: 25 °C; Sun Spectrum: AM 1.5) for monocrystalline silicon (m-Si) and polycrystalline silicon (p-Si) PV modules. By using sieve analysis, the particle sizes of coal dust have been divided into six groups which are in µm size and as follows: (−38), (+38/−53), (+53/−75), (+75/−106), (+106/−250), (+250/−500). Artificial pollution has been created by uniformly distributing coal dust of certain size and weight onto PV modules. Three different weights of coal dust (5 g, 10 g and 15 g) have been employed for every single size of coal dust. In order to investigate the effect of any particle size and any weight of coal, the performance of PV modules has been investigated by measuring voltage, current and power. The data set consisting of electrical parameters has been used to develop a model by using Adaptive Neuro-Fuzzy Inference System (ANFIS). Comparison of experimental and ANFIS results have been given by calculating of Root Mean Square Error (RMSE) and coefficient of determination (R2). The performance indices have been calculated as RMSE = 0.18719 and R2 = 0.99803 for m-Si, RMSE = 0.87098 and R2 = 0.99714 for p-Si PV modules. According to the results, for a given particle size and weight, the ANFIS model is quite successful in power estimation for PV modules.

Mines over matter: Effects of foliar particulate matter on the herbivorous insect, Helicoverpa armigera

AbstractCoalmines, which are major contributors of particulate matter in the form of coal dust, are expanding globally into rural environments. However, ecological effects on organisms interacting with coal‐dusted foliage in mining landscapes are unknown. We tested how the behaviour, development and survival of a polyphageous insect herbivore, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is affected by consuming tomato leaves Lycopersicon esculentum laden with coal dust. We tested (a) feeding site establishment preference of neonates, (b) feeding behaviour and leaf consumption of late‐instar larvae, (c) survival of neonates and (d) survival and development of late‐instar larvae. We found that coal dust consumption increased the mortality of late‐instar larvae but did not influence their development. Despite long‐term implications for survival, late‐instar larvae did not adjust their feeding behaviour or the amount of leaf material consumed in response to foliar coal dust. Contrastingly, when neonate H. armigera were given a choice, they avoided establishing themselves on the coal‐dusted adaxial surface of leaves. Neonate mortality was 99% within 7 days, with no effect of coal dust. Our study provides the first data on the impact of coal dust on an insect herbivore. This has implications for ecological interactions in landscapes adjoining coalmines.

Development of Combustion Technology for Methane Emitted from Coal‐Mine Ventilation Air Systems

AbstractFugitive gas emissions from coal mining are widely known to be significant contributors to the emission of alkanes, mainly methane, to the environment. Utilization of coal‐mine ventilation air methane (VAM) is a crucial mission to minimize methane emission in the atmosphere. This paper reviews current technology for mitigation and utilization of methane emissions from coal mining. Challenges and opportunities for each technology are discussed together with their benefits/disadvantages. Catalytic combustion technology is recommended as the best option due to the low and variable concentration of methane in coal‐mine ventilation air, as well as its high volumetric flow. Herein, current developments in flameless combustion are discussed in detail with a few highlights on palladium‐based catalyst development. The remaining uncertainties and obstacles in the development of palladium‐based catalysts for VAM are also discussed. This paper highlights a few important practical aspects that necessitate further detailed investigation, such as catalyst deactivation phenomena, the stability of the catalyst under humid conditions, and the effect of coal dust on catalytic activity and stability. Notably, a pressure decrease, heat recovery/self‐sustaining, and long‐term deactivation are key for the successful development of VAM catalytic combustors.

An animal model to evaluate the toxic effects of coal dust

An animal model to evaluate the toxic effects of coal dust

Ocular findings in coal miners diagnosed with pneumoconiosis

Objective: Our study aimed at evaluating ocular findings and structural changes in coal mine workers who were chronically exposed to coal mine dust and diagnosed with pneumoconiosis.Methods: Ocular findings of 161 eyes of 81 patients diagnosed with pneumoconiosis who had previously worked or are currently working in coal mines were analyzed. Forty-six coal mine workers and sex matched healthy people (n = 20) participated in the study. Workers who had early changes of pneumoconiosis were included in Group 1 (n = 17), workers diagnosed with pneumoconiosis were included in Group 2 (n = 29), and healthy subjects were included in Group 3 (n = 20). Outcome measures were the difference in peripapillary retinal nerve fiber layer (RNFL) thickness, choroidal thickness (CT), central macular thickness (CMT) and tear function tests between the groups.Results: RNFL thickness values in Group 1 and 2 were lower than in Group 3, the control group, in all quadrants except the temporal quadrant. However, there was no statistically significant difference in peripapillary RNFL thickness values in any quadrants among the three groups (p > 0.05). Central subfoveal choroidal thickness and CMT measurements were thinner in Group 1 and 2 than in the control group. However, this difference among groups was not statistically significant (p > 0.05). Mean schirmer's test result was 8.8 ± 1.6 mm in group 1, 7.1 ± 1.8 mm in Group 2 and 11.5 ± 3.6 mm in the control group. Mean tear break up time (BUT) test result was 7.1 ± 1.3 seconds (sec) in Group 1, 6.5 ± 1.8 sec in Group 2 and 10.4 ± 2.9 s in the control group. The Schirmer's test and BUT test results were both statistically significantly lower in coal mine workers (Group 1 and 2) compared to the control group. Group 1 and Group 2 did not show statistically significant difference in terms of Schirmer's test and BUT test results.Discussion: The association between pneumoconiosis and coal mine dust contiguity is thought to be due to the effect of coal dust by producing chronic inflammation. In addition, there are several trace elements in coal dust which are toxic to vital tissues. In this study, ocular findings suggest that systemic levels of trace elements and chronic inflammation may not reach to a level that influences ocular structures. Nonetheless, tear functions seem to be affected in coal mine workers.Conclusion: This study suggests that the systemic effect of coal mine dust in ocular structures is not evident. However, direct contact with coal mine and fume leads to a decrease in tear function tests.

Nanoaerosol fraction of man-made coal dust and its effect on the explosion hazard of dust-methane-air mixtures

57 Explosions of combustible gases and coal dust in coal mines all over the world often lead to highfatality accidents. To reliably evaluate the explosion hazard of mines and choose an efficient means of explosion pro� tection there, it is necessary to make fundamental studies of the mechanism of aerosol formation in mechanical crushing of coal and the effect of the aero� sol on the combustion of gas mixtures. From the late XIX century to the present, the effect of coal dust on the combustion of gas mixtures has been intensely investigated. As a rule, such investigations are per� formed in a spherical bomb (1-3), a tube (4, 5), or a premixed flame (6) containing particles at high dust concentration (10-100 g/m 3 at a medium average size

Effect of Coal Dust on Coalbed Methane Wells Productivity

CBM has the largest reserve except for conventional natural gas and is the cleanest energy. However, neither coal seam permeability nor CBM vertical well productivity has been determined when the immigration of coal dust are considered, which restricts the economic CBM exploitation. Based on coal seam characteristics, use permeability parallel path model and CBM seepage equation. The results show that with different ratio of non-clogging path and the total path, coal seam permeability and CBM vertical well productivity may either increase or decrease.

Frictional resistance of coal dust fouled uniformly graded aggregates

Large deposits of coal over vast expanse of lands attract mining companies, power stations and petrochemical companies and thus the development of coal towns with rail and road networks. High traffic volume of large quantities of coal across coal cities often result in the gradual accumulation of fine coal dust particles on road pavements, rail ballast and sleepers. The effect of coal dust on the Direct Shear Friction Angles (DSFA), Direct Shear Interface Friction Angles (DSIFA) and Direct Shear Modulus (DSM) of uniformly graded gravel aggregate were investigated. The results show that at increased coal content, the DSFA of the gravel tends to the DSFA of the coal. The rate of decrease of DSFA was dependent on the moisture content of the coal fouled gravel. The DSIFA was higher than the DSFA at any degree of coal fouling. The DSM at small displacement was more sensitive to changes in moisture content of the fouled gravel than friction angles and is thus a better indicator of coal fouling effect. Key words: Angle of friction, gravels, direct shear strength, interface shear strength.

Effects of coal dust and temperature on CO<SUB>2</SUB> emission in two soil types in Shanxi Province

Effects of coal dust and temperature on CO<SUB>2</SUB> emission in two soil types in Shanxi Province

Coal Dust Pollution Effects on Wetland Tree Species in Richards Bay,South Africa

In this study, the effects of coal dust on four, sympatric, wetland tree species in Richards Bay Harbour were investigated. We tested the hypothesis that leaf micromorphology influenced dust accumulation and that coal dust occluded stomata and reduced photosynthetic performance of three mangroves, Avicennia marina, Bruguiera gymnorrhiza and Rhizophora mucronata, and a mangrove associate, Hibiscus tiliaceus. To investigate leaf micromorphology, leaf blade material of the four species was prepared following standard procedures and viewed under scanning electron microscopy. Gas exchange and chlorophyll fluorescence measurements were made at saturating light (>1000 μmol m−2 s−1) and high temperature (>25 °C) on leaves that were either covered or uncovered with coal dust. There was no evidence of occlusion of stomata by dust. Dust accumulation in A. marina and H. tiliaceus was exacerbated by the presence of a dense mat of trichomes on the undersurface of the leaves, as well as by the sticky brine secreted by salt glands in the former species.Coal dust significantly reduced CO2 exchange, Photosystem II (PS II) quantum yield and electron transport rate (ETR) through PS II in A. marina and H. tiliaceus but not in the other two mangroves. Reduction in photosynthetic performance was attributed to reduction in light energy incident on the photosynthetic tissues.

Early change of pulmonary ventilation in new coal miners

To study the early effects of coal dust on lung function in new underground coal miners. Two hundred and eighty-seven male miners were selected from new employees at the Xuzhou Mining Group Company as study group, and 132 male students at a mining technical school were selected as control. Data collection included: individual demographic parameters, family medical history, occupational history, and smoking history, measurement of dust concentrations in work areas, and lung function tests. This prospective cohort study took place over 3 years during which time total dust and respirable dust concentrations in the new coal miners' work areas were measured twice each month. For both miner and student groups, FVC and FEV(1) were tested initially before dust exposure, and then 15 times over the 3 years. The average total dust and respirable dust concentrations in the miners' work areas were 23.8 mg/m(3) and 8.9 mg/m(3) respectively, which greatly exceeded national health criteria. During the first year of dust exposure, the miners's average FVC was higher than that of the controls (5.19 L vs 4.92 L, P < 0.01). During the 2nd and 3rd year the difference in average FVC between miners and control group was not significant (5.14 L vs 5.12 L, P > 0.05). Before dust exposure, the miners' FEV(1) was significantly higher than that of the control group (4.48 L vs 4.28 L). In the miners group, FEV(1) declined rapidly during the first year following dust exposure (from 4.48 L to 4.25 L), and in the 2nd and the 3rd year the average FEV(1) of the miners was significantly lower than that of controls (4.34 L vs 4.56 L, P < 0.01), although there were some fluctuations during the follow-up period. Overall, the average FEV(1) of miners group showed a significant decline during the study. There were significant correlations between FVC or FEV(1) and age, height, weight, and smoking. The three-year total loss of FVC and FEV(1) in smoking miners (154 ml, 184 ml) were greater than in non-smoking miners (83 ml, 91 ml). There are apparent effects of coal dust on lung function in new underground coal miners, with FEV(1) being more impacted than FVC. Smoking may aggravate the effect of dust exposure on reducing lung function.

The effects of coal dust on photosynthetic performance of the mangrove , Avicennia marina in Richards Bay, South Africa

Richards Bay, on the northern KwaZulu-Natal coast, is the largest coal exporting port in South Africa. The coal is stored at the Richards Bay Coal Terminal (RBCT) prior to export. Dust from coal operations is a major problem in the Richards Bay area. In this study, we tested the hypothesis that coal dust adversely affects photosynthetic performance of Avicennia marina (Forssk.) Vierh., the dominant mangrove species in the harbour. Photosynthetic performance was determined on 10 trees by measuring carbon dioxide uptake and chlorophyll fluorescence parameters at two elevation sites and on upper and lower leaf surfaces that were covered or uncovered with coal dust. Measurements were made on five clear, sunny days at saturating light (>1000 μmol m −2s −1) and high temperature (28–30 °C). Coal dust significantly reduced carbon dioxide exchange of upper and lower leaf surfaces by 17–39%, the reduction being generally greater on the lower leaf surface that is covered by a dense mat of trichomes and salt glands. The reduction in carbon dioxide exchange by coal dust was higher at the high elevation site that supported isolated dwarfed trees. The chlorophyll fluorescence data indicated that leaves coated with dust exhibited significantly lower photosystem II (PS II) quantum yield, lower electron transport rate (ETR) through PSII and reduced quantum efficiency of PSII ( F v F m). The chlorophyll fluorescence data supported the gas exchange measurements and are consistent with reduced photosynthetic performance of leaves coated with coal dust.

Effects of coal dust on species composition of mosses and lichens in an arid environment

A wind-borne plume of coal dust has been deposited on the soil and vegetation next to a coal storage area at a power generation plant in Oregon (U.S.A.). Correlated with the deposition of coal dust were significantly increased soil temperatures, decreased pH, and increased moisture-holding properties. Some heavy metal concentrations were also higher on the plume. These differences are possibly responsible for the lower frequencies and diversity of lichen species on the plume. Moss diversity, frequency and percent cover are similar on and off the plume with the exception of Ceratodon purpureus. The increased cover of C. purpureus may be attributed to heavy metal tolerance on the plume.

Effects of coal dust on plant growth and species composition in an arid environment

Prevailing south-west winds have deposited a plume of coal dust on the soil and vegetation next to a coal storage area at a power generation plant in Oregon. Few differences in the frequency and percent cover of vascular plants, or in biomass of perennials were found, but the biomass of annuals was significantly higher on the coal dust plume. Phenological differences among the vascular plants are possibly due to differences in soil temperature on and off the plume early in the growing season. Lichen frequency and percent cover was much higher off the plume. Different combinations of moss species occurred on and off the plume, but percent cover and frequency were similar in both locations.

97/03268 Effects of coal dust on IL-1 secretion by rat alveolar macrophage

97/03268 Effects of coal dust on IL-1 secretion by rat alveolar macrophage

Macrophage-Stimulated Effects of Coal Dust on Synthesis of Extracellular Matrix Proteins by Type II Pulmonary Epithelial Cells

Abstract The influence of coal dust on the alveolar type II pulmonary epithelium may involve direct dust-type II cell interactions or indirect effects mediated through production of cytokines or other products by nearby alveolar macrophages. Previous studies showed an effect of anthracite coal dust (PSOC 867) in modulating synthesis of extracellular matrix components by the type II cell in a dose-dependent manner. The present study confirms those observations and suggests further indirect effects due to type II cell-alveolar macrophage interactions during dust exposure in vitro. Exposure of type II cells to 867 (750 μg/ml) altered synthesis of matrix proteins. Coculture of alveolar macrophages with type II cells did not change synthesis of extracellular matrix proteins by control pneumocytes, but significantly increased the response of the cells to 867. Tumor necrosis factor-α (TNF-α) was evaluated as a possible mediator of the latter macrophage effect. Exogenous TNF-α caused a modest dose-dependent stimu...

96/01901 Effect of coal dust fuel on heat transfer in the tuyere zone of a blast furnace

96/01901 Effect of coal dust fuel on heat transfer in the tuyere zone of a blast furnace

Evaluation of serum type III procollagen peptide as an exposure marker in retired coal workers.

Serum type III procollagen peptide (PIIIP), a degradation product of the type III collagen precursor, has been put forward as an exposure marker for mineral dust. We evaluated PIIIP levels as a marker of exposure to and effects of coal dust in retired coal miners (n = 104). To this end: (a) the individual cumulative dust exposure was calculated from job-exposure matrices, and (b) in addition to routine chest radiography (CR) of all miners according to the criteria of the International Labour Organisation (ILO), a subgroup (n = 46) was screened by high-resolution computed tomography (HRCT). Profusion score (CR and HRCT) tended to increase with cumulative dust exposure, even in the absence of CR evidence for pneumoconiosis (i.e. CR < or = 0/1, n = 35). In contrast to our previous findings in active miners, PIIIP levels were not increased in miners as compared with non-dust-exposed controls (n = 29), and no differences were observed between miners without (ILO = 0/0) and miners with coal workers' pneumoconiosis (CWP; ILO > or = 0/1). No trend in PIIIP versus pneumoconiosis stage was present, either by CR or by the more sensitive HRCT score. PIIIP was also unrelated to any lung function parameter (FEV1, FVC, impedance, diffusion capacity). Age, medication, medical history and smoking habits had no significant effect on PIIIP levels. In the miners with CWP (i.e. ILO > 0/0, n = 28) a significant negative correlation was present between PIIIP values and (log) cumulative dust exposure. This decrease in serum PIIIP levels with increasing cumulative exposure may be due to chronic adaptive changes in type III collagen deposition and/or breakdown. Other relations between exposure and PIIIP were not observed. In conclusion, the present findings do not support the use of serum type III procollagen peptide as a marker of exposure to and (early) interstitial or respiratory effects of coal dust.