Engineering geomechanics characteristics of roadways in deep soft rock at Hegang Xing'an Coal Mine were studied and the nature of clay minerals of roadway surrounding rock was analyzed. This paper is to solve the ...Engineering geomechanics characteristics of roadways in deep soft rock at Hegang Xing'an Coal Mine were studied and the nature of clay minerals of roadway surrounding rock was analyzed. This paper is to solve the technical problems of high stress and the difficulty in supporting the coal mine, and provide a rule for the support design. Results show that mechanical deformation mechanisms of deep soft rock roadway at Xing'an Coal Mine is of ⅠABⅡABCⅢABCD type, consisting of molecular water absorption (the ⅠAB -type), the tectonic stress type + gravity deformation type + hydraulic type (the ⅡABC -type), and the ⅢABCD -type with fault, weak intercalation and bedding formation. According to the compound mechanical deformation mechanisms, the corresponding mechanical control measures and conversion technologies were proposed, and these technologies have been successfully applied in roadway supporting practice in deep soft rock at Xing'an Coal Mine with good effect. Xing'an Coal Mine has the deepest burial depth in China, with its overburden ranging from Mesozoic Jurassic coal-forming to now. The results of the research can be used as guidance in the design of roadway support in soft rock.展开更多
The purpose of this work is to remove Pb（II） from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-m...The purpose of this work is to remove Pb（II） from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy（FTIR）, Solid carbon nuclear magnetic resonance spectroscopy（CNMR））, silicon-29 nuclear magnetic resonance spectroscopy（Si NMR））, and X-ray diffraction spectroscope（（XRD） were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb（II） from the aqueous solution. The Pb（II）-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy（FTIR））,scanning electron microscopy（SEM））, and X-ray photoelectron spectroscopy（（XPS））. From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb（II）. Kinetic studies indicated that the adsorption of Pb（II）followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb（II） ions was 430 mg/g. Thus, the waste linear low-density polyethylene-g-poly（acrylic acid）-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb（II） adsorbent.展开更多
基金partially supported by program for the New Century Excellent Talents in University (No. NCET-08-0833)the National Natural Science Foundation of China (No. 41040027)the Special Fund of Basic Research and Operating Expenses of China University of Mining and Technology, Beijing
文摘Engineering geomechanics characteristics of roadways in deep soft rock at Hegang Xing'an Coal Mine were studied and the nature of clay minerals of roadway surrounding rock was analyzed. This paper is to solve the technical problems of high stress and the difficulty in supporting the coal mine, and provide a rule for the support design. Results show that mechanical deformation mechanisms of deep soft rock roadway at Xing'an Coal Mine is of ⅠABⅡABCⅢABCD type, consisting of molecular water absorption (the ⅠAB -type), the tectonic stress type + gravity deformation type + hydraulic type (the ⅡABC -type), and the ⅢABCD -type with fault, weak intercalation and bedding formation. According to the compound mechanical deformation mechanisms, the corresponding mechanical control measures and conversion technologies were proposed, and these technologies have been successfully applied in roadway supporting practice in deep soft rock at Xing'an Coal Mine with good effect. Xing'an Coal Mine has the deepest burial depth in China, with its overburden ranging from Mesozoic Jurassic coal-forming to now. The results of the research can be used as guidance in the design of roadway support in soft rock.
基金supported by the USM short-term grant (Ac No.: 8044043)by the USM fellowship scheme for PhD study (to M. Irani)Water Program at University of Wyoming
文摘The purpose of this work is to remove Pb（II） from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy（FTIR）, Solid carbon nuclear magnetic resonance spectroscopy（CNMR））, silicon-29 nuclear magnetic resonance spectroscopy（Si NMR））, and X-ray diffraction spectroscope（（XRD） were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb（II） from the aqueous solution. The Pb（II）-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy（FTIR））,scanning electron microscopy（SEM））, and X-ray photoelectron spectroscopy（（XPS））. From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb（II）. Kinetic studies indicated that the adsorption of Pb（II）followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb（II） ions was 430 mg/g. Thus, the waste linear low-density polyethylene-g-poly（acrylic acid）-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb（II） adsorbent.
