检索结果-南通市图书馆

Effects of Light and heavy rare earths on Anti-Degradation of Nodular Cast Iron

在线全文

学校读者我要写书评

暂无评论

引用

Journal of rare earths 2006年第1期24卷 103-107页

作者：王丽萍郭二军陈洪彬王敬泽李大勇 School of Materials Science and Engineering Harbin University of Science and Technology Harbin 150080 China School of Materials Science and Engineering Harbin University of Science and Technology Harbin 150080 China2. School of Mechanical & Electrical Engineering Harbin Engineering University Harbin 150001 China

The effects of rare earths with different contents on anti-degradation of Y base heavy rare earths-magnesium and cerium base light rare earths-magnesium nodular cast iron were studied. Curves of the relationship between the spheroidization grade of liguid iron treated by different nodulizers and holding time were obtained. The results show that the more the remains of the rare earth, the longer the anti-degradation time, the liquid iron was treated either by Y-Mg-Si or by Ce-Mg-Si nodulizer. When the rare earth remains are above certain quantity, the spheroidization grade starts to decline. When liquid iron treated by either Y-Mg-Si or Ce-Mg-Si nodulizer with proper remains of rare earths about 0.04% 0.06%（mass fraction）, the anti-degradation is the best, and the remains of Mg being about 0.04% -0.07% （mass fraction）. rare earths-Mg nodulizer with moderate RE remains is better than that of Mg-Si nodulizer in anti-degradation property. However, Y-Mg-Si nodulizer with moderate remins of Re is better than Ce-Mg-Si nodulizer. Sometimes Ce-Mg- Si nodulizer can be used for the production of heavy section nodular cast iron.

关键词： metal materials nodular cast iron anti-degradation Ce base light rare earths heavy rare earths

Yttrium chloride-modified Au/AC catalysts for acetylene hydrochlorination with improved activity and stability

在线全文

学校读者我要写书评

暂无评论

引用

Journal of rare earths 2017年第11期35卷 1083-1091页

作者： Jinhuo Ke Yuxin Zhao Yan Yin Kun Chen Xinping Duan Linmin Ye Youzhu Yuan State Key Laboratory of Physical Chemistry of Solid Surfaces National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-EstersCollege of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China

The addition of yttrium chloride(YCl) to an activated carbon-supported Au catalyst(Au/AC) can markedly promote the catalytic performance of acetylene hydrochlorination to the vinyl chloride monomer(VCM), The structure and physicochemical features of the YCl-modified catalysts(Y-Au/AC)were measured by X-ray diffraction, X-ray photoelectron spectroscopy, temperature-programmed reduction, CH-temperature programmed desorption, and scanning transmission electron *** presence of YClwas found suppressing the reduction of highly oxidized Au(δ=1,3) to metallic Au~0 dependently and thus retard the agglomeration of Au nanoparticles during the reaction. In addition,the additive of YClto the Au/AC catalyst greatly inhibits the coke deposition on the catalyst surface. The optimized catalyst with an atomic ratio of Y/Au = 5(1 wt% Au loading weight) yields an 87.8% acetylene conversion and almost 100% selectivity for VCM under the reaction of GHSV(CH) = 800 hat 180 ℃.The durability test indicates that the 5 Y-1 Au/AC catalyst maintains high catalytic activity for more than2300 h at 30 hGHSV(CH) and 180 ℃, indicating great promise as a non-mercury catalyst for PVC manufacture.

关键词： Yttrium heavy rare earths Acetylene hydrochlorination Gold catalyst Promoting effect Electronic effect

Effect of Cycling Loaded rare earths on Stripping Process in P507 Extraction System

在线全文

学校读者我要写书评

暂无评论

引用

Journal of rare earths 2006年第2期24卷 176-176页

作者： Wu Sheng Liao Chunsheng Jia Jiangtao Yan Chunhua State Key Lab of rare Earth Materials Chemistry and Applications Peking University Beijing 100871 China Beijing Institute of Founder rare Earth Science and Technology Co. Ltd. Beijing 100085 China

P507 （HEH [EHP]） is an important extractant for the separation of rare earth and is widely used in industry. Since the complexes of heavy rare earth ions with saponified P507 are so stable that the rare earth ions are difficult to be exchanged and stripped by H^＋ ions. Thus, the cycled extractant loads certain amount of heavy rare earth ion after stripped by acid. This amount of rare earth ions loaded in blank organic phase is named as the ＂cycling loaded rare earth ions （CLREs）＂. In the separation process of Tm^3＋, Yb^3 ＋, and Lu^3 ＋ , the amount of CLREs carl be more than 10% of the normal capacity of saponifiedorganic phase. In fact, CLREs affect the separation efficiency and decrease the purity of the products. Based on the extracting-stripping equilibrium and mass balance, the influence of different process parameters on the amount of CLREs was studied by computer simulation. The results indicate that higher acid consumption and more stripping stages are required to eliminate CLREs. For an industrial practice, however, the acid consumption and the number of stripping stage can be designed by choosing an economic process and controlling CLREs at a reasonable level.

关键词： countercurrent extraction stripping process computer simulation heavy rare earths