共查询到18条相似文献,搜索用时 156 毫秒
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前言铌和钽都是难熔金属,它们的特点是有很高的熔点,事实上,在钽铁矿石、铌铁矿石和烧绿石等几种矿石中均发现铌和钽伴生在一起。另外,还有相当数量的钽、铌是从锡渣中回收的。铌是英国化学家C.Hatchett在1801年 相似文献
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总结了亚洲金属网公布的有关日本2003年、2004年及2005年1月-5月钽铌原料与制品的进出口统计数据.分析了日本钽铌市场的状况。预计2005年日本钽的总需求量为331t,同此下降6.5% 相似文献
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为V—22飞机开发钛铸件 总被引:7,自引:0,他引:7
对钽,铌碳化物工业的发展及生产厂家,中国生产钽,铌碳化物的主要方法,生产的钽,铌碳化物的主要品种和质量标准,钽,铌碳化物的主要应用领域进行了较详细的介绍并展望了中国钽,铌碳化物的发展趋势。 相似文献
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低品位钽铌矿物萃取分离工艺的改进 总被引:3,自引:0,他引:3
采用 70 %的仲辛醇对低品位钽铌矿的调酸液进行矿浆萃取。稀释后的仲辛醇密度、粘度降低 ,矿萃时分相快 ,产生“黑渣”少 ,两相相互夹带少。而提钽有机则采用10 0 %的仲辛醇。两种不同浓度的有机相分开循环 ,使提钽有机不受矿浆萃取的污染 ,提钽能力强 ,钽铌分离效果好。 相似文献
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含氟含氨氮废水的治理 总被引:1,自引:0,他引:1
介绍了钽铌冶炼含氟含氨氮废水的治理工程实例,从方法与原理、工艺流程、技术参数、工程效果、经济性分析、存在问题与改进等方面作了系统的说明,提出了用"组合处理法"对处理难度大的钽铌冶炼废水实现有效治理。 相似文献
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电容器用铌粉和钽粉制备技术的进展 总被引:1,自引:0,他引:1
综述了铌粉和钽粉的现行生产工艺及几种新的还原方法,介绍了金属热还原反应中的电化学反应机理。钽粉的现行生产工艺几乎都用亨特法,铌粉则大部分采用铝热还原法生产。通过对亨特法还原条件、稀释剂组成等各种工艺参数的改进,已经可以制备纯度高、形态可控的金属钽粉。铌粉新还原方法的研究主要包括金属预成形热还原法、镁等蒸气还原预成形氧化物粉末的方法、镁或钠的蒸气还原氯化物蒸气的气相还原法、以液氨为介质在低温液相中均相还原铌或钽的氯化物的方法、反应媒介熔盐在强搅拌条件下的液体镁热还原金属氧化物的方法等。 相似文献
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Thermal stability of anodically produced oxide layers on niobium and tantalum The anodic oxidation of niobium and tantalum yields glassy oxide layers with a certain oxygen deficit leading to the formation of oxygen vacancies. The concentration of vacancies determines the rate of diffusion of oxygen and the electronic conductivity in the oxide. Upon heating in air, anodic oxide films on tantalum retard the dissolution of oxygen into the metal and delay the formation of rapidly growing porous oxide layers. The retardation is due to the slow diffusion of oxygen in the oxide. The rates of the phase boundary reactions between niobium oxide and niobium and between niobium oxide and oxygen have been investigated measuring the electronic conductivity of the oxide layer. The reactions between niobium oxide and niobium proceeds by dissolution of oxygen into the metal and formation of oxygen vacancies. During contact with oxygen, oxygen vacancies in the oxide are filled up. 相似文献
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国内钽铌光度分析的进展 总被引:8,自引:0,他引:8
晋勇 《稀有金属材料与工程》1996,25(3):45-51
概述了近年来国内钽铌光度分析的进展情况,论述了各类显色剂及其显色反应的条件,重点介绍了提高测试灵敏度和改善选择性的方法。 相似文献
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Oxygen absorption by vanadium, niobium and tantalum at high temperatures and low pressures A general view is presented of the oxygen absorption by vanadium, niobium and tantalum at temperatures above 1000°C and at oxygen partial pressures below 10?2 torr. In this context the kinetics of oxygen dissolution is given a detailed treatment while oxidation is dealt with but shortly. The review includes a theoretical treatment of oxygen dissolution. In addition quantitative relations are given which enable the oxygen dissolution in vanadium, niobium and tantalum to be estimated at given conditions of temperature and oxygen pressure. 相似文献
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Corrosion research on niobium-tantalum alloys Following a discussion of the mechanical and electrical properties of niobium, tantalum and their alloys, the corrosion behaviour of these metals in different mineral acids and in potash lye is reported upon. It is shown that tantalum can be largely replaced by niobium through alloying without losing any of its high corrosion resistance to aqueous solutions. This knowledge should lead to a much wider application of the rare and expensive metal tantalum. 相似文献
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Alain Robin 《International Journal of Refractory Metals and Hard Materials》1997,15(5-6):317-323
The corrosion resistance of niobium, tantalum and Nb-20, 40, 60 and 80 wt% Ta alloys in boiling 20, 40, 60 and 80 wt% H2SO4 solutions is studied using the mass-loss technique. The corrosion rates of all materials increase with acid concentration and diminish initially with time. After nearly 200 h, the corrosion rates stabilize due to superficial oxide formation. The corrosion resistance increases with tantalum content. A preferential dissolution of niobium from the Nb-Ta alloys is noted. Recrystallization heat treatments reduce slightly the corrosion rates. The anodized materials are more corrosion resistant than the untreated ones during the first 200 h, but behave similarly for longer exposure times. 相似文献