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This work introduced the current situation of the development of domestic and foreign rare earths (RE) industry, discussed the strategic position of RE industry in China, analyzed the problems existing in the course of RE industry...
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This work introduced the current situation of the development of domestic and foreign rare earths (RE) industry, discussed the strategic position of RE industry in China, analyzed the problems existing in the course of RE industry development, made strategic thought about the transference from resource advantage to economic advantage, and put forward strategic suggestions about the development of RE industry in our country.
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The solid oxide fuel cell (SOFC) is a high-efficient and environmentally friendly power generation system. The rare earth oxide materials are used extensively in the manufacturing of SOFC components. In particular, the CeO_2 doped...
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The solid oxide fuel cell (SOFC) is a high-efficient and environmentally friendly power generation system. The rare earth oxide materials are used extensively in the manufacturing of SOFC components. In particular, the CeO_2 doped with Gd_2O_3 or Sm_2O_3, lanthanide perovskite oxides are indispensable and key materials for developing the intermediate temperature SOFC. The research and development status of application of high purity rare earth oxides in SOFC was overviewed. The rare earth oxide-based and -doped materials were discussed for the SOFC components. Concerning the rare earth oxides applicable to SOFC, several topics were also pointed out for further researching and developing.
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Concentrations and distribution patterns of rare earth elements (REEs) in the intertidal flat of Tianjin were studied using P 507 resin and ICP-MS analytical technology. The results show that average concentrations of REEs in the ...
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Concentrations and distribution patterns of rare earth elements (REEs) in the intertidal flat of Tianjin were studied using P 507 resin and ICP-MS analytical technology. The results show that average concentrations of REEs in the filtered (dissolved REEs) , unfiltered and interstitial water are 0.461 μg • L~(-1), 4. 98 μg • L~(-1) and 0. 845 μg • L~(-1), respectively. Their distribution patterns are similar to those in inland natural rivers, but quite different from those in oceans. The average concentrations of REEs in sediments and suspended matters are 161. 2 mg•L~(-1) and 168. 1 mg • L~(-1), respectively, which are much lower than those in sediments of natural rivers but higher than those in sediments of the continental shelf of East China Sea. It is suggested that REEs in sediments and suspended matters of intertidal flat can have mainly originated from terrestrial soils and thus their transportation and transformation processes are similar with those in rivers, and different from those in continental shelves. Pollutants discharged into the Bohai Bay do • not cause significant effect on REEs in the intertidal flat of Tianjin yet.
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The crystal and molecular structures of the Na[ Eu~Ⅲ (edta) ( H_2O)_3 ] • 4H_2O (edta = ethylenediaminetet-raacetic acid) and Na_4 [Eu_2~Ⅲ (Httha)_2] • 10H_2O (ttha = triethylenetetraminehexaacetic acid) complexes were determine...
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The crystal and molecular structures of the Na[ Eu~Ⅲ (edta) ( H_2O)_3 ] • 4H_2O (edta = ethylenediaminetet-raacetic acid) and Na_4 [Eu_2~Ⅲ (Httha)_2] • 10H_2O (ttha = triethylenetetraminehexaacetic acid) complexes were determined by single-crystal X-ray structure analyses. The crystal of Na [Eu~Ⅲ (edta) (H_2O)_3] • 4H_2O belongs to ortho-rhombic crystal system and Fdd2 space group. The crystal data are as follows; a = 1.9415 (15) nm, b = 3.544(3) nm, c = 1.203(9)nm, V = 8. 327(5) nm~3, Z = 16, M = 589.27, D_c = 1.880 g • cm~(-3, μ= 3.108mm~(-1) and F(000) = 4704. The final R and wR values are 0.0312 and 0.0750 for 2091 [Ⅰ > 2.0σ(Ⅰ)] reflections, and 0. 0344 and 0.0766 for all 3932 unique reflections, respectively. The [ Eu~Ⅲ (edta) (H_2O)_3 ]~- anion has a nine-coordinate pseu-do-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O, are from one edta ligand and three water molecules. The crystal of Na_4 [ Eu_2~Ⅲ (Httha)_2 ] • 10H_2O belongs to orthorhombic system and Pccn space group. The crystal data are as follows: a = 2.610(3)nm, b = 2.089(3)nm, c = 2.239(3)nm, V = 12.208 (28)nm~3, Z = 8, M = 1548.92, D_c = 1.686 g • cm~(-3), μ = 2.115 mm~(-1) and F (000) = 6272. The final R and wR are 0.0625 and 0.1091 for 9834 [ Ⅰ > 2.0σ (Ⅰ) ] reflections, and 0.1608 and 0.1471 for all 37818 unique reflections, respectively. The whole complex molecule is composed of two close parts in which each one has a nine-coordinate structure with distorted monocapped square antiprismatic prism. The ttha ligand in the [Eu_2~Ⅲ (Httha)_2]~(4-) anion coordinates to one Eu~Ⅲ ion with three N atoms and four O atoms and to the other Eu~Ⅲ ion with two O atoms.
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Low-Co AB_5-type Mm(NiCoMnAl)_5B_x (x = 0, 0. 1, 0. 2) electrode alloys were prepared by casting and rapid quenching. The effects of the rapid quenching on the lattice constants, microstructures and electrochemical characteristics...
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Low-Co AB_5-type Mm(NiCoMnAl)_5B_x (x = 0, 0. 1, 0. 2) electrode alloys were prepared by casting and rapid quenching. The effects of the rapid quenching on the lattice constants, microstructures and electrochemical characteristics of the alloys were investigated in detail. The obtained results show that the rapid quenching made lattice constants and cell volume increased. In a range of the quenching rate, rapid quenching can increase the discharge capacities of the alloys. However, the discharge capacity of the as-quenched alloy is lower than that of the as-cast alloy when quenching rate is more than a critical value. The cycle lives of the alloys increase monotonously with the increase of the quenching rate.
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Progress of studies on various multi-color long afterglow luminescence materials was reviewed. Two luminescent mechanism of long afterglow behavior were discussed. Further research and development prospects about the materials were proposed.
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The manufacturing method and functions of the RE polishing powder and comparation of the current situation of its production and application home and abroad were introduced. By analyzing the development of the liquid crystal (plat...
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The manufacturing method and functions of the RE polishing powder and comparation of the current situation of its production and application home and abroad were introduced. By analyzing the development of the liquid crystal (plate) display, the wide application of the RE polishing powder in the field of the liquid crystal display and predicts the development direction of the market of the RE polishing powder was presented. In addition, the development trends of the RE polishing powder industry and forecasts the application prospect of the RE polishing powder was analyzed.
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Lower automation level in industrial rare-earth extraction processes results in high production cost, inconsistent product quality and great consumption of resources in China. An integrated automation system for extraction process...
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Lower automation level in industrial rare-earth extraction processes results in high production cost, inconsistent product quality and great consumption of resources in China. An integrated automation system for extraction process of rare earth is proposed to realize optimal product indices, such as product purity, recycle rate and output. The optimal control strategy for output component, structure and function of the two-graded integrated automation system composed of the process management grade and the process control grade were discussed. This system is successfully applied to a HAB yttrium extraction production process and was found to provide optimal control, optimal operation, optimal management and remarkable benefits.
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There are at least three obvious trends in the developments of automotive market in China : the evolution of emission standards from Euro Ⅱ to Euro Ⅲ, the demand of lean-burn gasoline engine and the time of diesel vehicles. The ...
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There are at least three obvious trends in the developments of automotive market in China : the evolution of emission standards from Euro Ⅱ to Euro Ⅲ, the demand of lean-burn gasoline engine and the time of diesel vehicles. The latest application and advances of exhaust catalysts by Chinese researchers, using some high effcient, economical and durable methods to meet these changes in emission regulations laws and engine technologies, were described. Rare earth oxides, such as lanthana, ceria-based solid solutions and perovskite-type oxides, are widely used as excellent promoters for thermal stability, oxygen storage capacity and oxidation/reduction activity in these catalysts. Four phases in the development of the auto exhaust catalyst industry in China since the mid 1970s were reviewed. It is argued that China will become the center of global auto exhaust catalysts industry in the next decades with its economic, technical and environmental incentives, which greatly depends on the research and development of rare earth.
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La_(1-x)Sr_xGa_(1-y)Mg_Yo_(3-δ)(LSGM) electrolyte, La_(1-x)Sr_xCr_(1-y)Mn_Yo_(3-δ)(LSCM) anode and La_(1-x)Sr_xFe_(1-y) Mn_Yo_(3-δ)(LSFM) cathode materials were all synthesized by glycine-nitrate process (GNP) . The microstruct...
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La_(1-x)Sr_xGa_(1-y)Mg_Yo_(3-δ)(LSGM) electrolyte, La_(1-x)Sr_xCr_(1-y)Mn_Yo_(3-δ)(LSCM) anode and La_(1-x)Sr_xFe_(1-y) Mn_Yo_(3-δ)(LSFM) cathode materials were all synthesized by glycine-nitrate process (GNP) . The microstructure and characteristics of LSGM, LSCM and LSFM were tested via X-ray diffraction (XRD) , scanning electron microcopy (SEM) , A C impedance and four-probe direct current techniques. XRD shows that pure perovskite phase LSGM electrolyte and electrode (LSCM anode and LSFM cathode) materials were prepared after being sintered at 1400 ℃ for 20 h and at 1000 ℃ for 5 h, respectively. The max conductivities of LSGM (ionic conductivity) , LSCM (total conductivity) and LSFM (total conductivity) materials are 0.02, 10, 16 S·cm~(-1) in the air below 850 ℃, respectively. The conductivity of LSCM becomes smaller when the atmosphere changes from air to pure hydrogen at the same temperature and it decreases with the temperature like metal. The porous and LSGM-based LSCM anode and LSFM cathode films were prepared by screen printing method, and the sintering temperatures for them were 1300 and 1250 ℃, respectively. LSGM and electrode (LSCM and LSFM) materials have good thermal and chemical compatibility.
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