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XI Jin-hui YAO Guang-chun LIU Yi-han Zhang Xiao-ming 《材料研究与应用》2005,(3):179-184
In order to improve the properties of NiFe2O4 spinel based inert anode, some additive MnO2 were added to raw materials. NiFe2O4 spinel with MnO2 was made by solid-phase reaction at 1200℃for 6 h. XRD were carried out and the effects of MnO2 on density, conductivity and corrosion resistance were measured. XRD shows when MnO2 was added no new phases exist and MnO2 and NiFe2O4 formed solid solution; Mn4+ replaced parts of Fe3+ and the sample still had the structure of NiFe2O4 spinel. The crystal lattice of NiFe2 O4 spinel became aberrated when MnO2 was added, which can promote sintering, and improve density. Because Mn4+ replaces parts of Fe3+ and produces conduction electron, which can improve conductivity.The corrosion resistance of the samples was enhanced. When MnO2 is 1.0%, the sample‘s corrosion rate is 1/5 of that of the sample without MnO2. The reason is that Al2 O3 in the melt reacts with Mn4+ in the sample to produce MnAl2O4. MnAl2 O4 forms a dense protecting coat, which can prevent melt from eroding further.Because the key problem with inert anodes is anode corrosion, so we consider the optimal amount of MnO2 is 1.0%. 相似文献
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1 IntroductionThe idea of usinginert anodes (also called non-consumable or oxygen-producing anodes) in aluminumproductionis as old as the Hall-Heroult process ,dating backto one of theinventors ,Charles Martin Hall .Aninert anode is intended to replace a consumable carbon anode ,the cell reactionis Al2O3+3/2C 2Al +3/2CO2(1)The requirements for lowenergy consumption,lowproductioninvest ment andreducingthe emission ofgreenhouse gas speed the research for inert anodes in aluminumproduction. … 相似文献
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In order to improve the properties of NiFe2O4 spinel based inert anode, some additive MnO2 were added to raw materials. NiFe2O4 spinel with MnO2 was made by solid-phase reaction at 1200℃for 6 h. XRD were carried out and the effects of MnO2 on density, conductivity and corrosion resistance were measured. XRD shows when MnO2 was added no new phases exist and MnO2 and NiFe2O4 formed solid solution; Mn4+ replaced parts of Fe3+ and the sample still had the structure of NiFe2O4 spinel. The crystal lattice of NiFe2 O4 spinel became aberrated when MnO2 was added, which can promote sintering, and improve density. Because Mn4+ replaces parts of Fe3+ and produces conduction electron, which can improve conductivity.The corrosion resistance of the samples was enhanced. When MnO2 is 1.0,, the sample''s corrosion rate is 1/5 of that of the sample without MnO2. The reason is that Al2 O3 in the melt reacts with Mn4+ in the sample to produce MnAl2O4. MnAl2 O4 forms a dense protecting coat, which can prevent melt from eroding further.Because the key problem with inert anodes is anode corrosion, so we consider the optimal amount of MnO2 is 1.0,. 相似文献
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1 IntroductionThe carbon anode has been used in aluminum production for more than 100 years . But it has manyshortcomings ,of whichthe most notable problems are :(1) the consumption of anodes cause a great deal ofgood-quality carbon waste ,and the emission of the greenhouse gases and most of the sulfurous gases willpollute environment seriously ;(2) changing the anodes frequently affects the balance of heat ,and causehard work practices .Inert anodes can overcome the questions mentioned above … 相似文献
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ZHANG Shu-ting YAO Guang-chun LIU Yi-han 《材料研究与应用》2005,(3):557-562
In order to improve deficiencies of NiFe2O4 spinel used as matrix of inert anode in aluminium electrolysis, NiFe2O4/SiCp were prepared by the solid state reaction for the first time. Microstructural changes were observed by scanning electronic microscope and phase was determined with X-ray detector. Effect of sintering temperature and times on density, porosity and microstructure were researched, and the reasons that caused the difference were discussed deeply. At the same time the thermodynamical compatibility of NiFe2O4 and SiC was proved under 1200℃ by DTA.The results showed that the microstructure was more homogeneous when the sintering temperature reached 1 180℃and the density attained their maximum about 6 h sintering. The appropriate sintering technique of NiFe2 O4/SiCw composite materials was 1180℃× 6 h. 相似文献
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Study on sintering technique of NiFe2O4/SiCp used as matrix of inert anodes in aluminium electrolysis 下载免费PDF全文
In order to improve deficiencies of NiFe2O4 spinel used as matrix of inert anode in aluminium electrolysis, NiFe2O4/SiCp were prepared by the solid state reaction for the first time. Microstructural changes were observed by scanning electronic microscope and phase was determined with X-ray detector. Effect of sintering temperature and times on density, porosity and microstructure were researched, and the reasons that caused the difference were discussed deeply. At the same time the thermodynamical compatibility of NiFe2O4 and SiC was proved under 1200℃ by DTA.The results showed that the microstructure was more homogeneous when the sintering temperature reached 1 180℃and the density attained their maximum about 6 h sintering. The appropriate sintering technique of NiFe2 O4/SiCw composite materials was 1180℃× 6 h. 相似文献
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采用静电纺丝法制备了表面光滑、直径均匀、连续的一维NiFe_2O_4纳米丝。利用傅立叶变换红外光谱仪(FTIR)、X射线电子衍射(XRD)、扫描电子显微镜(SEM)和振动样品磁强计(VSM)对Ni Fe2O4纳米丝的结构、形貌和磁性能进行表征。结果表明,经500~900℃煅烧后均得到直径约为60 nm的纯相尖晶石型NiFe_2O_4纳米丝,且NiFe_2O_4纳米丝具有良好的软磁特性,其饱和磁化强度(Ms)和剩余磁化强度(Mr)随煅烧温度的升高而增大,900℃煅烧后Ms和Mr分别达到最大值35.56、13.29 A·m2/kg。经600℃焙烧后的Ni Fe2O4纳米丝Ms为30.56 A·m2/kg,矫顽力(Hc)达到最大值2.76 A/m,表明NiFe_2O_4的单畴临界尺寸约为28 nm。 相似文献
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1IntroductionResearch demonstratedthat NiFe2O4spinel used as matrix of inert anode was appropriatein aluminiumelectrolysis[1,2].NiFe2O4spinel is with chemical inertness and electrochemical stability,but alsois in pos-session of high temperature resistance,high stress and hardness[3].But then its electro conductibility,toughness and resistance to thermal shock can't meet a demand when it is used in aluminiumelectrolysis,resultedin the anode cracked and the purity of the electrolytic Al bastar… 相似文献
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我国钒资源和V2O5研究、生产的现状及前景 总被引:5,自引:0,他引:5
介绍了国内钒资源情况,V2O5的生产工艺,捉钒新技术研究现状和V2O5产品生产存在的问题和发展前景,提出应在保护资源和环境的前提下适度发展钒产品加工业。 相似文献
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通过固态反应,在1150℃、6h下制备出铝电解惰性阳极用NiFe2O4尖晶石粉末.经XRD物相分析,产物的衍射线位置和强度高低等和标准多晶衍射数据重合.SEM形貌观察,粒子为等轴形.通过制陶试验,考察了压制方式、粉末粒度、温度等因素对陶瓷体积密度和径向收缩率的影响,结果发现,双向压制较单向压制能实现较高的体积密度,压坯中密度分布的不均匀在很大程度上可以用双向压制来改善;尽可能降低粉末粒度能促进烧结,对制备致密化陶瓷有利;适当提高温度能促进烧结,提高体积密度.NiFe2O4陶瓷在Na3AlF6-Al2O3中的溶解性试验表明,镍和铁的饱和溶解度都极低,并不按化学计量数(1∶2)溶解. 相似文献
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通过对Li4Ti5O12材料固相合成工艺参数的研究,确定了最佳的分段固相合成工艺条件.结果表明:原料经650℃煅烧8h,然后再经900℃煅烧2h后,得到的Li4Ti5O12材料具有单一的尖晶石结构,且材料的颗粒尺寸较小;材料具有良好的电化学性能,其中以0.2 C充放电.放电比容量可以达到165.4mA·h/g;以0.2C充电,以不同倍率(0.5C,1C,3C及5C)放电,其放电比容量随放电倍率的增加,降低的幅度较大,其中5C放电比容量为0.5C的63.78%. 相似文献
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用石灰调节pH-蒸气吹脱法处理V2O5产生的高浓度氨氮废水.结果表明:在废水氨氮含量高达14.5g/L的情况下.用石灰调节pH=11.8,吹脱温度95℃以上.蒸气吹脱3.5h,可使废水的氨氮脱除率达99.5%以上,处理后的废水氨氮含量符合国家排放标准.氨氮回收率达93%,回收的氨水可用于沉钒工艺.处理后的废水可循环利用. 相似文献
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对江西某石煤钒矿进行无盐焙烧—酸浸—萃取提取五氧化二钒工艺研究。结果表明:该钒矿在-0.074mm占80%、焙烧温度800℃焙烧3h,硫酸浸出,五氧化二钒的浸出率超过90%;浸出液溶剂萃取,反萃液硫酸氨沉钒,最终得到纯度超过98%的五氧化二钒产品,综合回收率超过80%。 相似文献
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采用等静压气氛烧结法制备NiFe2O4基金属陶瓷惰性阳极,在不同温度下进行电解试验,通过分析电解试样的表层形貌及组织成分,研究电解温度对NiFe2O4基金属陶瓷腐蚀的影响,并对其熔盐腐蚀行为进行探讨.研究结果表明:较高温度有利于电解稳定性的提高及表面致密保护层的形成,在925℃和960℃电解温度下阳极较为稳定,槽电压维持在3.0~4.0V之间;在880℃电解温度下阳极出现肿胀和开裂,槽电压异常升高,Al2O3的溶解度较低,抑制了阳极与电解质熔体(尤其是Al2O3)的交互作用,降低了材料的耐蚀性能. 相似文献
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溶剂萃取法从石煤酸浸液中提取V_2O_5的新工艺研究 总被引:1,自引:1,他引:0
研究了新型萃取试剂从酸浸液中提取五氧化二钒的新工艺。结果表明:有机相(A)15%+煤油75%+添加剂10%组成的有机溶剂萃取率为99.55%;用80g/L氯化钠作反萃剂,反萃率为98.49%。酸浸液经萃取—反萃后,水相五氧化二钒浓度从9.8g/L富集到115.30g/L,并且主要杂质均被除去,有利于后续提钒工艺地进行。 相似文献