共查询到19条相似文献,搜索用时 640 毫秒
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采用常规铝粉及超细铝粉对镍铬合金粉进行包覆,制备镍铬铝粉末.结果表明,采用超细铝粉包覆的粉末表面包覆更严、更均匀.采用超细铝粉对两种形状不同的镍铬合金粉进行包覆,形状不规则的粉末更易被包覆.将以上三种包覆型粉末制备成涂层,超细铝粉包覆粉末制备的涂层孔隙率更小,涂层更致密. 相似文献
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共沸蒸馏制备超细氧化铝粉 总被引:1,自引:0,他引:1
采用共沸蒸馏工艺成功地制备了超细氧化铝粉,通过共沸蒸馏能有效地消除粉末的硬团聚。本文还系统地分析了粉末硬团聚形成的机理,从而制得了粒径d_(50)为0.47μm的超细氧化铝粉。 相似文献
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对二氧化钒超细粉末的各种制备方法、应用及进展情况进行了综述,并指出了二氧化钒超细粉末制备技术的发展方向。 相似文献
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介绍了煤矸石制备氢氧化铝、氧化铝、高纯超细α-氧化铝的工艺原理及过程,三氧化二铝含量大于35%的煤矸石是铝业生产潜在的矿物资源,用煤矿石生产氧倾铝系列产品,在弥补铝土矿资源不足的同时,也为煤矸石应用探索了一条新途径。 相似文献
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AlN粉末制备技术概述 总被引:1,自引:0,他引:1
介绍了氧化铝(AlN)陶瓷的特性,并以金属铝直接氮化法和氧化物高温碳热还原法为重点,对目前国内外比较成熟的几种AlN粉末合成方法的制备工艺、反应机理及各种方法的优缺点进行评述,并提出了当前在AlN粉末的制备方面存在的问题。 相似文献
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综述了近年来国内外超细/纳米W-Cu复合粉末的研究进展,对超细/纳米W-Cu复合粉末的多种制备方法——机械合金化、机械-热化学法、喷雾干燥法、溶胶-凝胶法等进行了介绍和技术特点分析。 相似文献
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高纯超细α-Al2O3纳米粉的研究进展 总被引:1,自引:0,他引:1
综合评述了目前国内外高纯超细α-Al2O3的研究进展.介绍了高纯超细氧化铝的制备方法,通过对各种方法的描述和对比,得出其优缺点,为高纯氧化铝的制备研究和生产指出了方向. 相似文献
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目前,我国存在许多以氯化铝溶液为原料制备氧化铝的方法.然而,这些方法均存在着许多不足之处,如产生废酸和废盐、制备条件要求较高、反应中涉及有毒有害物质等.基于这种情况,在氯碱工业的启发下,东北大学已经提出了一种电转化AlCl3水溶液制备氧化铝的新方法.并且该方法已经得到了试验性验证.文中主要研究了电转化新方法和氢氧化钠滴定法制备的氧化铝前驱体在红外光谱及粒度分布方面的不同;同时研究了这2种方法制备的氧化铝在物相、形貌及粒度等方面的差异.结果表明,这2种方法制备的氧化铝前躯体均含有铝元素及Al-OH键,且其焙烧产物也均为氧化铝.与氢氧化钠滴定法制备的氧化铝相比,电转化法制备的氧化铝形貌较规整且为片状结构,而氢氧化钠滴定法制备的氧化铝形状不规则.同时,电转化法制备的氧化铝及其前驱体的粒径小于氢氧化钠滴定法制备的氧化铝及其前躯体的粒径,但前者的粒径分布比后者的粒径分布更为均匀. 相似文献
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V. S. Rimkevich A. A. Pushkin I. V. Girenko T. Yu. Eranskaya 《Russian Journal of Non-Ferrous Metals》2014,55(4):344-349
Physicochemical processes of the fluoride processing of kyanite concentrates under the influence of additional components are studied theoretically and experimentally in the range of temperatures of 20–550°C and curing times of 0.12–4.5 h. The optimal conditions of feed stock sintering with ammonium bifluoride, sublimation of ammonium hexafluorosilicate, formation of aluminum fluoride and alumina, and synthesis of amorphous silica nanoparticles are found. Thermodynamic and kinetic parameters of chemical reactions are calculated. The studies are used as a basis for the development of the fluoride method of alumina generation from kyanite concentrates with the complex recovery of other useful components. 相似文献
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进行了利用Na2AlO4溶液制备高效聚合氯化铝及其水处理特性的试验研究,分析了氧化铝浓度及碱基度对聚合氯化铝中铝聚合形态组成的影响,以及总铝浓度、合成条件对碱基度、铝态分布及其水处理混凝效果的影响。试验表明,采用氧化铝厂的Na2AlO4溶液完全可以制备性能优异的聚合氯化铝产品。 相似文献
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Christian T. Mutale William J. Krafick Douglas A. Weirauch 《Metallurgical and Materials Transactions B》2010,41(6):1368-1374
The wetting and spreading of molten aluminum on TiB2 substrates between the aluminum melting point and 1033 K (760 °C) was investigated in the presence of different types of
fluxes. The wetting and spreading behavior is observed to depend on the flux, its melting point, its chemistry, and its ability
to dissolve alumina. When the flux melting point is higher than the melting point of aluminum, the molten aluminum takes on
an initial spherical shape as a result of the thin alumina layer on its surface. After the flux is melted, it dissolves the
alumina layer on the liquid aluminum surface causing the aluminum to wet and spread on the substrate. When the flux melts
before the aluminum, the alumina layer on the solid aluminum surface is dissolved into the flux. In this case, the aluminum
surface in contact with the molten flux is alumina layer free. Thus, the aluminum does not take a spherical shape after melting;
it rapidly melts, wets, and spreads on the substrate. The use of a flux allows the wetting behavior of aluminum on TiB2 to be observed at lower temperatures than previously reported. 相似文献
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G. K. Abikenova V. A. Kovzalenko G. A. Ambarnikova A. T. Ibragimov 《Russian Journal of Non-Ferrous Metals》2008,49(2):91-96
Physicochemical characteristics of Krasnogorskii off-grade bauxite used at the Pavlodar aluminum plant are investigated, and its qualitative and quantitative composition is presented. It is found that, in the system of alumina production, the evaporation unit serves as the place of maximum oxidation of all forms of sulfur of lower valences to sulfates. The main methods of removal of sulfur in the technological cycle of alumina production are demonstrated. These are removal of ferruginous sands, an increase in amount of the reducing agent in the sintering charge, and periodic removal of the soda-sulfate mixture. 相似文献
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氧化铝浓度的分布与电解过程的电流效率、温室气体排放及运行稳定性等参数都息息相关。针对传统铝电解多相多场的离线仿真速度响应不及时、对硬件要求高、仿真结果无法在线或直接用于指导生产实践等问题,将离线仿真数据与检测数据有效融合,开展铝电解动态仿真的研究,即基于实时阳极电流信号及未来预测值,结合动态U型曲线关系,在CFD氧化铝浓度的离线仿真结果库的基础上,对氧化铝浓度进行了动态仿真。为最终实现铝电解数字孪生体分布式信号采集-电流预测-氧化铝浓度动态仿真的一体化提供先进思路与技术方法。 相似文献
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T. N. Vetchinkina 《Russian Metallurgy (Metally)》2009,(2):120-128
Crystal-optical, X-ray diffraction, and thermogravimetric methods are used to study the polymorphic transformations in the products of calcination of the aluminum hydroxide produced by the decomposition and carbonization of aluminate solutions; the aluminum oxide produced by the decomposition of pure grade crystal hydrates of aluminum salts; and the alumina extracted upon the beneficiation of the mineral part of coaly rock with sulfuric, hydrochloric, and nitric acids. The morphology of the products of the thermal decomposition of the initial compounds is examined. The effect of impurities and a reducing agent on the formation of the structural modifications of alumina during heat treatment is revealed. 相似文献