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新型炼铝电极材料 总被引:3,自引:0,他引:3
研制了一种新型铝电解金属陶瓷惰性阳极,阳极基体由Fe-Ni-Co-Al-O构成.在电解温度960℃,氧化铝质量浓度为6.0%,阳极电流密度为1.0 A/cm2,分子比为2.6的电解质中对其进行了10 h的电解.电解过程平稳,电解铝产品纯度达到96%~99%,阳极气体中氧气的含量为98%,反电动势为2.45 V,高于理论值0.25~0.35 V.此阳极具备较好的导电性、抗氧化和耐腐蚀性.采用X射线衍射和电子探针微分析仪(EPMA)对电解后的阳极进行分析,发现阳极表面存在铁酸镍、铝酸铁等尖晶石型化合物,阳极表面下层为铝酸铁、钴酸镍等陶瓷相以及金属相;金属相和陶瓷相相互弥散分布构成结构致密的金属陶瓷层. 相似文献
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Results from 100 h electrolysis testing of NiFe2O4 based cermet as inert anode in aluminum reduction 总被引:2,自引:1,他引:2
1 Introduction Since the Hall-Héroult process was applied in aluminum production, an inert anode was always the target that the aluminum industry was seeking for in the new technology field[1]. Some selection criteria have been defined in order to ident… 相似文献
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Preliminary testing of NiFe_2O_4-NiO as ceramic matrix of cermet inert anode in aluminum electrolysis 总被引:4,自引:0,他引:4
1 INTRODUCTIONTheideaofusinginertanodes(alsocallednon consumableoroxygen evolvinganodes)inaluminumproductionisasoldastheHall H啨roultprocess ,dat ingbacktothediscoveryofoneoftheinventors ,Hall[1] .Inertanodesareintendedtoreplacethecon sumablecarbonanodethatiscurrentlyused .Withacarbonanode ,thecellreactionisAl2 O3+ 3/ 2C =2Al+ 3/ 2CO2 (1)where acryolite basedmelt(Na3AlF6 AlF3 CaF2 )atnear 96 0℃servesassolventforthealumina .Withaninertanode ,thecellreactionwillbeAl2 … 相似文献
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铁酸镍基金属陶瓷惰性阳极材料的研究进展 总被引:1,自引:0,他引:1
惰性阳极铝电解技术的发展主要基于经济和环境的考虑,对铝电解工业的长远发展具有重要意义,已成为铝电解工业进步的关键技术。合金惰性阳极具有易加工成形、良好的抗热震性和导电性,金属陶瓷惰性阳极兼顾陶瓷的高温热稳定性及金属的高导电性和高韧性,二者已成为惰性阳极的主要候选材料体系,并进行了工程化铝电解试验研究。近年来,惰性阳极的研究集中在合金阳极表面保护膜形成与溶解的动态平衡控制、金属陶瓷组成与结构优化、惰性阳极的电解腐蚀机制及抑制技术等方面。综述了铝电解用合金阳极和金属陶瓷惰性阳极的近期研究进展,从材料学的角度介绍铁酸镍基金属陶瓷的组成优化、烧结、电解腐蚀特性等方面的最新研究成果。 相似文献
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采用冷压气氛烧结制备17(Cu-10Ni)-(NiFe2O4-10NiO)金属陶瓷,并作为阳极在960°C下分别进行10和40h的铝电解试验。对电解前后金属陶瓷的显微结构、物相成分进行分析检测。对电解质及阴极金属中的杂质含量进行分析,研究阳极组成中Fe、Ni和Cu元素的腐蚀行为。研究发现:在电解过程中,在材料表面形成NiFe2O4相致密层,该致密层随电解时间的延长而增厚。在NiFe2O4相致密层形成与增厚过程中,出现NiFe2O4相吞噬NiO相和金属相氧化的现象,金属陶瓷中Cu元素优先腐蚀溶解。并着重讨论NiFe2O4相致密层形成与增厚过程中金属相的腐蚀形式及NiO相向NiFe2O4相的转变机制。 相似文献
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(85Cu-15Ni)/(10NiO-NiFe2O4) cermets were prepared with Cu-Ni mixed powders as toughening metallic phase and 10NiO-NiFe2O4 as ceramic matrix. The phase composition, microstructure of composite and the effect of metallic phase content on bending strength, hardness, fracture toughness and thermal shock resistance were studied. X-ray diffraction analysis indicates the coexistence of (Cu-Ni), NiO and NiFe2O4 phases in the cermets. Within the content range of metallic phase from 0% to 20% (mass fraction), the maximal bending strength (176.4 MPa) and the minimal porosity (3.9%) of composite appear at the metallic phase content of 5%. The fracture toughness increases and Vickers' hardness decreases with increasing metal content. When the thermal shock temperature difference (At) is below 200 ℃, the loss rate of residual strength for 10NiO-NiFe2O4 ceramic is only 8%, but about 40% for (85Cu-15Ni)/(10NiO-NiFe2O4)cermets. As At is above 200 ℃, the residual strength sharply decreases for sample CN0 and falls slowly for samples CN5-CN20. 相似文献
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铝电解用NiFe2O4-Cu金属陶瓷惰性阳极的制备 总被引:16,自引:2,他引:16
以高温固相合成法合成的NiFe2O4陶瓷粉体和金属Cu粉为原料, 采用冷压-烧结法制备了Cu含量在5%~20%之间的NiFe2O4-Cu金属陶瓷惰性阳极, 研究了烧结气氛和烧结温度对其物相组成、微观形貌和基本物理性能的影响. 结果表明 通过控制烧结气氛中氧分压在NiO和Cu2O的离解反应平衡氧分压之间, 可以制备出具有目标物相组成的NiFe2O4-Cu金属陶瓷; 烧结温度和保温时间对所得NiFe2O4-Cu金属陶瓷的相对密度有较大影响; NiFe2O4和Cu之间的不润湿性限制了NiFe2O4-Cu金属陶瓷烧结温度的提高和保温时间的延长, 在保证金属相分布均匀且不溢出的前提下, 所制备的NiFe2O4-Cu金属陶瓷的相对密度较小; 金属相Cu含量越高, NiFe2O4-Cu金属陶瓷最高烧结温度越低、最长保温时间越短, 从而相对密度越低、孔隙率越高; 除了尽量降低金属相含量外, 还可向NiFe2O4-Cu金属陶瓷中添加其他金属如Ni和Co等, 以改善陶瓷相与金属相之间的润湿性, 以提高烧结温度, 进而提高其相对密度和耐腐蚀性能. 相似文献
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1 INTRODUCTIONInaluminumelectrolysis process ,thequantitygradeofcarbonanoderestrictsnotonlytheimprove mentofproductiontechniques ,butalsotheadvance mentofproductiontargets.Formany years ,largenumberofresearchesweredonetoimprovethephysi cal,chemicalandelectrochemicalperformanceoftheanodeinordertoenhancecurrentefficiency ,reduceenergyconsumption ,decrease productioncostandcleancircumstanceofaluminum plantanditssur roundingarea .Recently ,manylaboratoryresearchresultsweresuccessfullyappliedf… 相似文献
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制备铝电解用NiFe2O4-10NiO基金属陶瓷惰性阳极,并在实验室电解槽中考察其电解腐蚀性能。结果表明,电解过程中虽然惰性阳极在960°C熔盐电解质中表现出优异的耐腐蚀性能,但采用XRD、SEM/EDX和金相分析其物相组成和微观结构后发现,电解后阳极中的金属相发生了优先腐蚀,在阳极表面产生大量孔洞。NiFe2O4相中的 Fe 元素的优先溶解可能导致 NiFe2O4晶粒的不均匀腐蚀。溶解在电解液中的 Al2O3与阳极中的 NiO 或FeO 发生反应生成的 NiFe2O4-NiAl2O4-FeAl2O4相对 NiO 相的吞并以及体积膨胀,阳极表面形成致密的NiFe2O4-NiAl2O4-FeAl2O4保护层。因此,致密的NiFe2O4-NiAl2O4-FeAl2O4保护层可以阻挡阳极表面金属相的损失和陶瓷相的腐蚀。 相似文献
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Effect of Ni content on corrosion behavior of Ni/(10NiO-90NiFe2O4) cermet inert anode 总被引:1,自引:0,他引:1
Ni/(10NiO-90NiFe2O4) cermet inert anodes with metal Ni content of 0, 5, 10, 15 and 20 (mass fraction, %) were prepared and their corrosion behavior in Na3AlF6-Al2O3 melts was investigated in laboratory electrolysis tests. The results indicate that the content of metal Ni in anodes has little effect on the steady-state concentration of impurities Ni and Fe in electrolyte and the values range in (114-173)×10^-6 and (287-385)×10^-6, but the content of impurities in the metal aluminum manifolds. There is preferential corrosion for metal Ni in NiO-NiFe2O4 based cermet anodes. Considering the corrosion resistance and electrical conductivity, the cermet containing 5%Ni (mass fraction) behaves best among NiO-NiFe2O4 based cermet anodes studied, and should be further studied. 相似文献
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1 Introduction It is well known that the current aluminum reduction cell with carbon consumable anode has many disadvantages. So the concept of inert anode was introduced, with which the disadvantages can be avoided completely. A lot of research work has… 相似文献
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1 INTRODUCTIONAluminummetallurgyadoptsthemethodofhightemperaturemeltsaltelectrolysisdevelopedonehun dredyearsago .Intheprocessofresearchanddevel opmentinthisfield ,physicalchemistry ,electro chemistry ,materialscience ,roboticizedtechnologyandsoonwerecombinedwithaluminummetallurgytechniques,makingthebasicprincipleoftheHall Heroultprocessbeingmoredeeplyrealizedbypeople .Furthermore ,thistechnologywasdevelopedcon stantlyandbecamemoreandmoreperfectinordertofurthersaveenergy ,reducerawmateri… 相似文献
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本文提出了惰性阳极铝电解中以氧化铝中α-Al2O3含量,电解温度和室温为变量的理论能耗计算公式和以氧化铝中α-Al2O3含量,电解温度,室温和电流效率为变量的理论能耗电压计算公式。 相似文献
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Densification of Ni-NiFe_2O_4 cermets for aluminum electrolysis 总被引:2,自引:1,他引:2
1INTRODUCTION Aluminumelectrolysisconsumesenormous energyandresources,andtheconsumptionwillbeconsiderablydecreasedbyintroductionofinert anodeandwettablecathode.However,underthe toughworkingconditionofaluminumelectrolysis,i.e.highlycorrosiveNa3AlF6Al2O3moltensalts athightemperature(940960℃),theinert anodesnecessaryforthesuccessfulproductionofaluminummighthavethefollowingproperties:be insolubleinafluoridemelt,beresistanttowards anodeoxygen,havegoodelectricalconductivity,possessadequatestr… 相似文献
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大尺寸NiFe2O4-10NiO/17Ni型金属陶瓷惰性阳极的制备 总被引:1,自引:0,他引:1
研究以PVA为主要成分的粘结剂体系的热分解特性对大尺寸粉末压坯脱脂行为的影响,发现PVA的不均匀热分解是造成大尺寸粉末压坯脱脂失效的原因之一,开发一种具有稳定热分解反应特性的新型粘结剂体系,实现大尺寸粉末压坯的无缺陷热脱脂;研究烧结气氛、金属相的添加对NiFe2O4-10NiO致密化行为的影响。结果表明:N2气氛烧结及加入Ni可有效提高NiFe2O4-10NiO陶瓷基体的烧结致密度,1350℃时于N2气氛中烧结的NiFe204.10NiO/5Ni型金属陶瓷材料的相对密度达到97.28%。采用优化工艺实现d120mmX140mm深杯状NiFe2O4-10NiO/17Ni金属陶瓷惰性阳极脱脂预烧坯的烧结,所得烧结坯平均相对密度为95.21%。 相似文献
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从新型工业化的基本内涵出发,结合铝电解工业的发展状况对铝电解工业走新型工业化的方向和途径进行了论述,强调走新型工业化道路是铝电解生产技术进步的必然结果. 相似文献
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LAIYanqing LIUYexiang YANGJianhong THONSTADJomar 《稀有金属(英文版)》2002,21(2):117-122
The anodic overvoltage of the carbon anode in aluminum electrolysis is of the order of 0.6 V at normal currem densities. However, it can be reduced somewhat by doping the anode carbon with various inorganic compounds. A new apparatus was designed to improve the precision of overvoltage measurements. Anodes were doped with MgAl2O4 and AlF3both by impregnation of the coke and by adding powder, and the measured overvoltage was compared with that of undoped samples. For prebake type anodes baked at around 1150℃, the anodic overvoltage was reduced by 40-60 mV,and for Soderberg type anodes, baked at 950 ℃, by 60-80 mV. 相似文献