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Preparation of high-purity neodymium chloride by solvent extraction in the mixer-settlers： A pilot-scale investigation

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Journal of Rare Earths 2017年第11期35卷 1133-1140页

作者： Fujian Li Qiaoyan He Yanliang Wang Hong Zhou Shuibo Zhang Xiaoqi Sun Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fuzhou Fujian 350002 PR China Xiamen Institute of Rare Earth Materials Haixi Institute Chinese Academy of Sciences Xiamen 361021 PR China University of Chinese Academy of Sciences Beijing 100039 PR China Ganzhou Rare Earth Group Co. Ltd. China Southern Rare Earth Ganzhou 341000 PR China

A novel purification process based on mixer-settlers for high-purity NdClwas developed. Acidic solution and pure NdClsolution were compared to scrub the less-extractable rare earths(REs)(La, Ce, and Pr)from loaded organic phase. The extractant with low-degree saponification was evaluated to remove the more-extractable element(Sm). Then the RE impurities(La, Ce, Pr, and Sm) in Nd were purified by an integrated process. Furthermore, effect of smuggling behavior on the purification of NdClin mixersettlers was studied. Based on the investigation mentioned above, the pilot-scale purification process for NdClwith a purity of 99.999% was developed, and the total recovery was about 99%.

关键词： Solvent extraction Purification Neodymium high-purity Mixer-settlers

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Preparing high-purity iron by direct reduction?smelting separation of ultra-high-grade iron concentrate

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International Journal of Minerals,Metallurgy and Materials 2020年第4期27卷 454-462页

作者： Feng Li Qing-jie Zhao Man-sheng Chu Jue Tang Zheng-gen Liu Jia-xin Wang Sheng-kang Li School of Metallurgy Northeastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

A new process for preparing high-purity iron(HPI)was proposed,and it was investigated by laboratory experiments and pilot tests.The results show that under conditions of a reduced temperature of 1075°C,reduced time of 5 h,and CaO content of 2.5wt%,a DRI with a metallization rate of 96.5%was obtained through coal-based direct reduction of ultra-high-grade iron concentrate.Then,an HPI with a Fe purity of 99.95%and C,Si,Mn,and P contents as low as 0.0008wt%,0.0006wt%,0.0014wt%,and 0.0015wt%,respectively,was prepared by smelting separation of the DRI using a smelting temperature of 1625°C,smelting time of 45 min,and CaO content of 9.3wt%.The product of the pilot test with a scale of 0.01 Mt/a had a lower impurity content than the Chinese industry standard.An HPI with a Fe purity of 99.98wt%can be produced through the direct reduction?smelting separation of ultra-high-grade iron concentrate at relatively low cost.The proposed process shows a promising prospect for application in the future.

关键词： ultra-high-grade iron concentrate high-purity iron coal-based direct reduction smelting separation pilot test

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Optical Methods in Orientation of high-purity Germanium Crystal

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Journal of Crystallization Process and Technology 2013年第2期3卷 60-63页

作者： Guojian Wang Yongchen Sun Yutong Guan Dongming Mei Gang Yang Angela Alanson Chiller Bruce Gray Department of Chemistry University of South Dakota Vermillion USA. Department of Physics University of South Dakota Vermillion USA

Two optical methods, namely crystal facet reflection and etching pits reflection, were used to orient and high-purity germanium crystals. The X-ray diffraction patterns of three slices that were cut from the oriented and crystals were measured by X-ray diffraction. The experimental errors of crystal facet reflection method and etching pits reflection method are in the range of 0.05° - 0.12°. The crystal facet reflection method and etching pits reflection method are extremely simple and cheap and their accuracies are acceptable for characterizing high purity detector-grade germanium crystals.

关键词： Reflection Method high-purity Germanium Crystal

Synthesis and formation mechanism of HfB_(2) ultrafine powders with low oxygen via flocculating settling assisted process and carbo/borothermal reduction

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Journal of Materials Science & Technology 2023年第33期164卷 229-239页

作者： Zhen Wang Yuan Cheng Kewei Li Tianxu Wang Mengen Hu Chunxue Zheng Xinyang Li Zhulin Huang Xiaoye Hu Yue Li Xinghong Zhang University of Science and Technology of China Hefei 230026China Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanotechnology Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China Anhui University Hefei 230039China Harbin Institute of Technology Harbin 150001China

In this study,ultrafine HfB_(2) powders with low oxygen were synthesized by a flocculating settling process which yielded ceramic precursors and subsequent carbo/borothermal reduction of the precursors.The liquid phase precursor method can achieve uniform mixing of components at the molecular level through multiple complexation reactions,and then realize the carbo/borothermal reduction reaction at a lower temperature to obtain ultrapure HfB2 powders.The as-resulted quasi-spherical HfB2 powders under the optimum conditions(atomic molar ratio M:B:C=1:2.8:10)calcined at 1500°C for 1 h have an average particle size of 205 nm and an oxygen content of 0.097 wt.%.Detailed analysis of the phase evolution of precursors shows that the formation of HfB2 particles is a mass diffusion mode from the external to internal HfO_(2)cores.We reveal that below 1300°C,HfC is not an intermediate product of HfB2 powder during the transition of precursors.Instead,HfC was formed as a by-product at high temperatures in the carbo/borothermal reduction process.The proposed formation mechanism of HfB_(2) is completely different from the traditional two-step transformation method.After the sintering of the ultrafine powders,the HfB_(2) ceramics show a relative density of 96.1%and superior mechanical properties compared to other works.Furthermore,by simply replacing the initial metal source,chlorinated group IV and V transitional metals(Ti,Zr,Ta,Nb)can also convert into high-purity and ultrafine diborides.This work shows that flocculating settling assisted carbo/borothermal reduction has potential in lot size production of various high-purity and ultrafine boride powders.

关键词： Boride powders Flocculating settling Low oxygen content high-purity

Geochemistry and petrology of superpure quartzites from East Sayan Mountains, Russia

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Acta Geochimica 2019年第1期38卷 22-39页

作者： A.M.Fedorov V.A.Makrygina A.I.Nepomnyaschikh A.P.Zhaboedov A.V.Parshin V.F.Posokhov Yu.V.Sokolnikova A.P.Vinogradov Institute of Geochemistry SB RAS Irkutsk National Research Technical University Irkutsk Scientific Center SB RAS Irkutsk State University Geological Institute SB RAS

Quartzites are widespread within Earth's lithosphere, but their highly pure varieties occur quite infrequently. With the development of alternative energy sources, including solar, and with increasing demand for high-purity quartz for optics, interest has risen in highpurity silicon-bearing materials. The quartzites discovered in the southeast part of the Eastern Sayan Mountains are particularly attractive for exploration in terms of their raw material quality and feasibility to be enriched. For this reason, their genesis also merits study. Available geochemical data show that chemogenic(d^(18)O>29.2%)siliceous-carbonate sediments of the Irkut Formation are fairly pure(impurity elements 0.9% impurities, but later, under the action of sliding slabs of ophiolite dynamothermal treatment reduced impurities to highly pure quartzites). The presence of only minor structural impurities is due to the enrichment capacity of superquartzites to 10.1 ppm(7.2 ppm under special conditions) of 10 elements: Fe, Al, Ti, Ca, Mg, Cu,Mn, Na, K, and Li.

关键词： high-purity quartz Superquartzite Gravitational sliding Dynamic metamorphism Recrystallization

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A Controlled Mixing Method for Stabilizing the purity and Reducing the Waste in Gas Delivery Systems

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Advances in Chemical Engineering and Science 2019年第1期9卷 11-26页

作者： Junsheng Wu Farhang Shadman Department of Chemical and Environmental Engineering University of Arizona Tucson Arizona USA

The variation of impurity concertation in the ultra-high purity (UHP) gases, delivered from cryogenic storage tanks and transported through long pipes, is a major problem in systems like those used in semiconductor manufacturing facilities. A method is developed for stabilizing the purity and reducing the gas consumption in these systems. This technique uses a dynamically controlled mixing of gases supplied by multiple cryogenic tanks. The control scheme uses software modules that simulate the processes that cause purity variation in both the cryogenic tanks and the transport lines. These processes include vaporization and supply in tanks, various modes of transport in delivery pipes, and the adsorption and desorption on surfaces. The method also includes and corrects for variations caused by transience in gas usage rate as well as ambient conditions.

关键词： high-purity Gases Cryogenic Impurity Drift Moisture