Clarification of the molecular mechanism underlying the interaction of coal with CH4, CO2, and H2 O molecules is the basis for an in-depth understanding of the states of fluid in coal and fluid-induced coal swelling/c...Clarification of the molecular mechanism underlying the interaction of coal with CH4, CO2, and H2 O molecules is the basis for an in-depth understanding of the states of fluid in coal and fluid-induced coal swelling/contraction. In terms of instrumental analysis, molecular simulation technology based on molecular mechanics/dynamics and quantum chemistry is a powerful tool for revealing the relationship between the structure and properties of a substance and understanding the interaction mechanisms of physical-chemical systems. In this study, the giant canonical ensemble Monte Carlo（GCMC） and molecular dynamics（MD） methods were applied to investigate the adsorption behavior of a Yanzhou coal model（C222H185N3O17S5）. We explored the adsorption amounts of CH4, CO2, and H2 O onto Yanzhou coal, the adsorption conformation, and the impact of oxygen-containing functional groups. Furthermore, we revealed the different adsorption mechanisms of the three substances using isosteric heat of adsorption and energy change data.（1） The adsorption isotherms of the mono-component CH4, CO2, and H2 O were consistent with the Langmuir model, and their adsorption amounts showed an order of CH4CO2〉CH4. In addition, at higher temperatures, the isosteric heat of adsorption decreased; pressure had no significant effect on the heat of adsorption.（3） CH4 molecules displayed an aggregated distribution in the pores, whereas CO2 molecules were cross arranged in pairs. Regarding H2 O molecules, under the influence of hydrogen bonds, the O atom pointed to surrounding H2 O molecules or the H atoms of coal molecules in a regular pattern. The intermolecular distances of the three substances were 0.421, 0.553, and 0.290 nm, respectively. The radial distribution function（RDF） analysis showed that H2 O molecules were arranged in the most compact fashion, forming a tight molecular layer.（4） H2 O molecules showed a significantly stratified distribution around oxygen-containing functional groups on the coal surface, and the b展开更多
This paper compares analytical and numerical methods by taking the forecasting of water yield of deep-buried iron mine in Yanzhou, Shandong as an example. Regarding the analytical method, the equation of infinite and ...This paper compares analytical and numerical methods by taking the forecasting of water yield of deep-buried iron mine in Yanzhou, Shandong as an example. Regarding the analytical method, the equation of infinite and bilateral water inflow boundary is used to forecast the water yield, and in the case of numerical simulation, we employed the GMS software to establish a model and further to forecast the water yield. On the one hand, through applying the analytical method, the maximum water yield of mine 1 500 m deep below the surface was calculated to be 13 645.17 m3/d; on the other hand, through adopting the numerical method, we obtained the predicted result of 3 816.16 m3/d. Meanwhile, by using the boundary generalization in the above-mentioned two methods, and through a comparative analysis of the actual hydro-geological conditions in this deep-buried mine, which also concerns the advantages and disadvantages of the two methods respectively, this paper draws the conclusion that the analytical method is only applicable in ideal conditions, but numerical method is eligible to be used in complex hydro-geological conditions. Therefore, it is more applicable to employ the numerical method to forecast water yield of deep-buried iron mine in Yanzhou, Shandong.展开更多
Heavy metal pollution brings extensive concerns since 1940s. In order to assess the heavy metal pollution on the farmland of Yanzhou coalfield, 216 soil samples and 54 combined samples were collected. Lead, cadmium, c...Heavy metal pollution brings extensive concerns since 1940s. In order to assess the heavy metal pollution on the farmland of Yanzhou coalfield, 216 soil samples and 54 combined samples were collected. Lead, cadmium, chromium, copper, zinc, and nickel contained in both topsoil and deep soil were analyzed using atomic absorbent spectrometry analyzer (AAS). Fuzzy clustering method was used in data processing. And fuzzy synthetic assessment was applied to assess the soil contamination by heavy metals. The result shows that Yanzhou coalfield has been polluted by the heavy metals to some extent.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.41072116,41102092,41302127,41372165)Special Research Foundation for the Doctoral Program of Higher Education of China(Grant No.20091402110002)+1 种基金Science Project of Taiyuan city(Grant No.120247-27)outstanding funding innovative projects for the graduate students by Shanxi Province in 2010
文摘Clarification of the molecular mechanism underlying the interaction of coal with CH4, CO2, and H2 O molecules is the basis for an in-depth understanding of the states of fluid in coal and fluid-induced coal swelling/contraction. In terms of instrumental analysis, molecular simulation technology based on molecular mechanics/dynamics and quantum chemistry is a powerful tool for revealing the relationship between the structure and properties of a substance and understanding the interaction mechanisms of physical-chemical systems. In this study, the giant canonical ensemble Monte Carlo（GCMC） and molecular dynamics（MD） methods were applied to investigate the adsorption behavior of a Yanzhou coal model（C222H185N3O17S5）. We explored the adsorption amounts of CH4, CO2, and H2 O onto Yanzhou coal, the adsorption conformation, and the impact of oxygen-containing functional groups. Furthermore, we revealed the different adsorption mechanisms of the three substances using isosteric heat of adsorption and energy change data.（1） The adsorption isotherms of the mono-component CH4, CO2, and H2 O were consistent with the Langmuir model, and their adsorption amounts showed an order of CH4CO2〉CH4. In addition, at higher temperatures, the isosteric heat of adsorption decreased; pressure had no significant effect on the heat of adsorption.（3） CH4 molecules displayed an aggregated distribution in the pores, whereas CO2 molecules were cross arranged in pairs. Regarding H2 O molecules, under the influence of hydrogen bonds, the O atom pointed to surrounding H2 O molecules or the H atoms of coal molecules in a regular pattern. The intermolecular distances of the three substances were 0.421, 0.553, and 0.290 nm, respectively. The radial distribution function（RDF） analysis showed that H2 O molecules were arranged in the most compact fashion, forming a tight molecular layer.（4） H2 O molecules showed a significantly stratified distribution around oxygen-containing functional groups on the coal surface, and the b
文摘This paper compares analytical and numerical methods by taking the forecasting of water yield of deep-buried iron mine in Yanzhou, Shandong as an example. Regarding the analytical method, the equation of infinite and bilateral water inflow boundary is used to forecast the water yield, and in the case of numerical simulation, we employed the GMS software to establish a model and further to forecast the water yield. On the one hand, through applying the analytical method, the maximum water yield of mine 1 500 m deep below the surface was calculated to be 13 645.17 m3/d; on the other hand, through adopting the numerical method, we obtained the predicted result of 3 816.16 m3/d. Meanwhile, by using the boundary generalization in the above-mentioned two methods, and through a comparative analysis of the actual hydro-geological conditions in this deep-buried mine, which also concerns the advantages and disadvantages of the two methods respectively, this paper draws the conclusion that the analytical method is only applicable in ideal conditions, but numerical method is eligible to be used in complex hydro-geological conditions. Therefore, it is more applicable to employ the numerical method to forecast water yield of deep-buried iron mine in Yanzhou, Shandong.
基金Project 30302408 supported by Land and Resource Ministry of China
文摘Heavy metal pollution brings extensive concerns since 1940s. In order to assess the heavy metal pollution on the farmland of Yanzhou coalfield, 216 soil samples and 54 combined samples were collected. Lead, cadmium, chromium, copper, zinc, and nickel contained in both topsoil and deep soil were analyzed using atomic absorbent spectrometry analyzer (AAS). Fuzzy clustering method was used in data processing. And fuzzy synthetic assessment was applied to assess the soil contamination by heavy metals. The result shows that Yanzhou coalfield has been polluted by the heavy metals to some extent.
