A novel high performance MgCl2/TiCl4 catalyst with tetrabutyloxsilicane as electron donor was pre-pared for ethylene slurry polymerization process. The properties of the catalyst such as particle size distribution, ca...A novel high performance MgCl2/TiCl4 catalyst with tetrabutyloxsilicane as electron donor was pre-pared for ethylene slurry polymerization process. The properties of the catalyst such as particle size distribution, catalytic activity, hydrogen responsibility and copolymerization performance were investigated and compared with commercial catalyst (imported catalyst). Copolymerization of ethylene and 1-butylene using the catalyst was stud-ied in a pilot plant. The composition, structure and property of the copolymer were characterized by 13C nuclear magnetic resonance (13C NMR) and gel permeation chromatography-Infrared (GPC-IR), and compared with those of the copolymer obtained from a commercial catalyst. In comparison with the commercial catalyst, the novel cata-lyst had a higher activity (up to 34.6 kg·g-1) and a better particle size distribution (PSD), and produced polymers having higher bulk density (up to 0.37 g·cm-3) with less fine resin. Meanwhile, the novel catalyst showed a higher hydrogen responsibility and better copolymerization performance. The results indicated that the copolymer obtained from the novel catalyst has a higher branch in the high molecular weight fraction and lower branch in the low mo-lecular weight fraction.展开更多
The ocean poly-metallic nodule was leached by using slurry electrolysis process in HCl-NaCl medium.The leaching rates of Mn,Co,Cu and Ni in the ocean poly-metallic nodule are all above 97%.Meanwhile,the high purity of...The ocean poly-metallic nodule was leached by using slurry electrolysis process in HCl-NaCl medium.The leaching rates of Mn,Co,Cu and Ni in the ocean poly-metallic nodule are all above 97%.Meanwhile,the high purity of electrolytic MnO2 is also obtained as an anode product.The effects of electrolysis electric quantity,acidity,temperature,slurry density,grain size and iron ions concentration were studied.The results show that the ocean poly-metallic nodule can be treated economically in the slurry electrolysis process.展开更多
Two different grinding processes were examined to determine the effect grinding has on the quality of a CWS. A series of slurries was prepared from Australian (Au) and Chinese (YZ) coals. Both types of coal were groun...Two different grinding processes were examined to determine the effect grinding has on the quality of a CWS. A series of slurries was prepared from Australian (Au) and Chinese (YZ) coals. Both types of coal were ground by a Chinese (CUMT) and an Australian (JK) grinding process. The performance tests of the prepared CWS showed that fluidity of all slurries was acceptable. The concentration of the CWS from YZ coal ground by the CUMT grinding process was higher than when the JK grinding process was used. The highest concentration was 70.14% in this case. The concentration of the CWS prepared from Au coal by the JK grinding process was higher than when the CUMT grinding process was used. The highest con- centration in this case was 70.97%. These differences are caused by the particle size distribution devel- oped during the different grinding processes.展开更多
The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst（BRICI）and improved ...The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst（BRICI）and improved polyethylene catalyst.The effects of catalyst structure on kinetic behavior were examined.The distribution of active centers in these catalysts was investigated by energy dispersive analysis by X-rays（EDAX）,and morphologies of catalyst particles and polymer products were examined by scanning electron microscope（SEM）.Hydrogen response and copolymerization performance were investigated and compared with the two catalysts.The results were correlated with the kinetic behavior of the two catalysts and appropriate models for polymer particle growth were presented.The improved polyethylene catalyst showed higher activity,better hydrogen response and copolymerization performance.展开更多
Microengines are regarded as the potential replacements for batteries.Aimed at the unsatisfactory thermal property of silicon used in the combustion chambers,ceramics are chosen as the construction material in this pa...Microengines are regarded as the potential replacements for batteries.Aimed at the unsatisfactory thermal property of silicon used in the combustion chambers,ceramics are chosen as the construction material in this paper.The fabrication process where alumina has been chosen as the microengine material is discussed.Vigorous FEA has been carried out,and it is found that the material satisfies the stress and deformation requirements of the design.Then the alumina fabrication process is described.Soft reusable polydimethylsiloxane(PDMS)moulds are produced from SU-8 resist masters,and alumina microengine parts are produced using the PDMS moulds.Images of the ceramic components show that the fabrication satisfies the design requirements.展开更多
文摘A novel high performance MgCl2/TiCl4 catalyst with tetrabutyloxsilicane as electron donor was pre-pared for ethylene slurry polymerization process. The properties of the catalyst such as particle size distribution, catalytic activity, hydrogen responsibility and copolymerization performance were investigated and compared with commercial catalyst (imported catalyst). Copolymerization of ethylene and 1-butylene using the catalyst was stud-ied in a pilot plant. The composition, structure and property of the copolymer were characterized by 13C nuclear magnetic resonance (13C NMR) and gel permeation chromatography-Infrared (GPC-IR), and compared with those of the copolymer obtained from a commercial catalyst. In comparison with the commercial catalyst, the novel cata-lyst had a higher activity (up to 34.6 kg·g-1) and a better particle size distribution (PSD), and produced polymers having higher bulk density (up to 0.37 g·cm-3) with less fine resin. Meanwhile, the novel catalyst showed a higher hydrogen responsibility and better copolymerization performance. The results indicated that the copolymer obtained from the novel catalyst has a higher branch in the high molecular weight fraction and lower branch in the low mo-lecular weight fraction.
基金Projects(50674014,50734005)supported by the National Natural Science Foundation of China
文摘The ocean poly-metallic nodule was leached by using slurry electrolysis process in HCl-NaCl medium.The leaching rates of Mn,Co,Cu and Ni in the ocean poly-metallic nodule are all above 97%.Meanwhile,the high purity of electrolytic MnO2 is also obtained as an anode product.The effects of electrolysis electric quantity,acidity,temperature,slurry density,grain size and iron ions concentration were studied.The results show that the ocean poly-metallic nodule can be treated economically in the slurry electrolysis process.
基金This project received funding from the Australian governmentas part of the Asia-Pacific Partnership on Clean Development and Climate
文摘Two different grinding processes were examined to determine the effect grinding has on the quality of a CWS. A series of slurries was prepared from Australian (Au) and Chinese (YZ) coals. Both types of coal were ground by a Chinese (CUMT) and an Australian (JK) grinding process. The performance tests of the prepared CWS showed that fluidity of all slurries was acceptable. The concentration of the CWS from YZ coal ground by the CUMT grinding process was higher than when the JK grinding process was used. The highest concentration was 70.14% in this case. The concentration of the CWS prepared from Au coal by the JK grinding process was higher than when the CUMT grinding process was used. The highest con- centration in this case was 70.97%. These differences are caused by the particle size distribution devel- oped during the different grinding processes.
文摘The study concerns the use of MgCl2-supported high-activity Ziegler-Natta catalysts for the polymerization of ethylene.In particular,two types of catalysts were investigated,which were N-catalyst（BRICI）and improved polyethylene catalyst.The effects of catalyst structure on kinetic behavior were examined.The distribution of active centers in these catalysts was investigated by energy dispersive analysis by X-rays（EDAX）,and morphologies of catalyst particles and polymer products were examined by scanning electron microscope（SEM）.Hydrogen response and copolymerization performance were investigated and compared with the two catalysts.The results were correlated with the kinetic behavior of the two catalysts and appropriate models for polymer particle growth were presented.The improved polyethylene catalyst showed higher activity,better hydrogen response and copolymerization performance.
基金Sponsored by the Natural Science Foundation of Heilongjiang Province (Grant No.E2004-06)
文摘Microengines are regarded as the potential replacements for batteries.Aimed at the unsatisfactory thermal property of silicon used in the combustion chambers,ceramics are chosen as the construction material in this paper.The fabrication process where alumina has been chosen as the microengine material is discussed.Vigorous FEA has been carried out,and it is found that the material satisfies the stress and deformation requirements of the design.Then the alumina fabrication process is described.Soft reusable polydimethylsiloxane(PDMS)moulds are produced from SU-8 resist masters,and alumina microengine parts are produced using the PDMS moulds.Images of the ceramic components show that the fabrication satisfies the design requirements.
