Electrolytic manganese residue(EMR), a high volume byproduct resulting from the electrolytic manganese industry, was used as a cheap and abundant chemical source for preparing MnO2 and EMR-made calcium silicate hydrat...Electrolytic manganese residue(EMR), a high volume byproduct resulting from the electrolytic manganese industry, was used as a cheap and abundant chemical source for preparing MnO2 and EMR-made calcium silicate hydrate(EMR-CSH). The MnO2 is successfully synthesized from the metal cations extracted from EMR, which can effectively recycle the manganese in the EMR. By the combination of XRD, SEM and EDX analysis, the as-prepared MnO2 is found to exhibit a single-phase with the purity of 90.3%. Furthermore, EMR-CSH is synthesized from EMR via hydrothermal method. Based on the detailed analyses using XRD, FT-IR, FE-SEM, EDX and BET surface area measurement, the product synthesized under the optimum conditions(p H 12.0 and 100 °C) is identified to be a calcium silicate hydrate with a specific surface area of 205 m2/g incorporating the slag-derived metals(Al and Mg) in its structure. The as-synthesized material shows good adsorption properties for removal of Mn2+ and phosphate ions diluted in water, making it a promising candidate for efficient bulk wastewater treatment. This conversion process, which enables us to fabricate two different kinds of valuable materials from EMR at low cost and through convenient preparation steps, is surely beneficial from the viewpoint of the chemical and economical use of EMR.展开更多
Geosynthetic-reinforced and pile-supported （GRPS） embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are expos...Geosynthetic-reinforced and pile-supported （GRPS） embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are exposed through a lot of applications on conventional technique of GRPS embankment （called CT embankment）, i.e., intolerable settlement and lateral displacement, low geosynthetic efficiency, etc. In view of these disadvantages, the fixed geosynthetic technique of GRPS embankment （called FGT embankment） is developed in this work. In this system, the geosynthetic is fixed on the pile head by the steel bar fulcrum and concrete fixed top. The principles and construction techniques involved in the FGT embankment are described firstly. Then, the numerical analysis method and two-stage analysis method are used to study the performance of FGT embankment, respectively. It is shown that the FGT embankment can provide a better improvement technique to construct a high embankment over soft ground.展开更多
基金Project(21376273)supported by the National Natural Science Foundation of ChinaProject(2010FJ1011)supported by the Research Fund of Science and Technology of Hunan Province,China
文摘Electrolytic manganese residue(EMR), a high volume byproduct resulting from the electrolytic manganese industry, was used as a cheap and abundant chemical source for preparing MnO2 and EMR-made calcium silicate hydrate(EMR-CSH). The MnO2 is successfully synthesized from the metal cations extracted from EMR, which can effectively recycle the manganese in the EMR. By the combination of XRD, SEM and EDX analysis, the as-prepared MnO2 is found to exhibit a single-phase with the purity of 90.3%. Furthermore, EMR-CSH is synthesized from EMR via hydrothermal method. Based on the detailed analyses using XRD, FT-IR, FE-SEM, EDX and BET surface area measurement, the product synthesized under the optimum conditions(p H 12.0 and 100 °C) is identified to be a calcium silicate hydrate with a specific surface area of 205 m2/g incorporating the slag-derived metals(Al and Mg) in its structure. The as-synthesized material shows good adsorption properties for removal of Mn2+ and phosphate ions diluted in water, making it a promising candidate for efficient bulk wastewater treatment. This conversion process, which enables us to fabricate two different kinds of valuable materials from EMR at low cost and through convenient preparation steps, is surely beneficial from the viewpoint of the chemical and economical use of EMR.
基金Foundation item： Project（51278216） supported by the National Natural Science Foundation of China Project（11-2-05） supported by the Scientific and Technological Project for Shanxi Communication Construction, China Project（HF-08-01-2011-240） supported by the Graduates＇ Innovation Fund of Huazhong University of Science and Technology, China
文摘Geosynthetic-reinforced and pile-supported （GRPS） embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are exposed through a lot of applications on conventional technique of GRPS embankment （called CT embankment）, i.e., intolerable settlement and lateral displacement, low geosynthetic efficiency, etc. In view of these disadvantages, the fixed geosynthetic technique of GRPS embankment （called FGT embankment） is developed in this work. In this system, the geosynthetic is fixed on the pile head by the steel bar fulcrum and concrete fixed top. The principles and construction techniques involved in the FGT embankment are described firstly. Then, the numerical analysis method and two-stage analysis method are used to study the performance of FGT embankment, respectively. It is shown that the FGT embankment can provide a better improvement technique to construct a high embankment over soft ground.
