模糊系统在阳极效应故障诊断中的应用

为了提高生产效率、降低成本,通过对铝电解过程中的阳极效应故障进行有效的检测和预报,减少阳极效应的发生。通过对阳极效应发生机理和故障发生时相关特征量变化趋势的分析,基于模糊逻辑理论,建立了模糊系统故障检测模型,实现了对阳极效应的检测和预报。实验运行结果表明,利用模糊系统对阳极效应的故障诊断预报的方法行之有效,提前了预报时间,提高了预报的准确率。利用模糊系统对阳极效应进行故障诊断的方法,可有效地降低铝电解中阳极效应发生率,降低能耗,具有良好的应用前景。     

阳极效应的预报

阳极效应是铝电解中一种特征现象。跟踪槽电阻是一众所周知的分析阳极效应的方法。在研究边部打壳预焙阳极电解槽阳极效应前15分钟的槽电阻与时间的曲线时发现,每当阳极效应发生前,槽电阻便特征性地升高。基于这些观察并根据平均槽电阻以及特征枟电阻对时间变化曲线的斜率,我们开发研制出了计算机预报阳极效应的计算程序。业已证     

阳极效应预报方法

预焙阳极电解槽一般有10～30块碳素焙烧阳极。这些阳极在电解过程中逐渐消耗。从而每隔一定时间要更换一次阳极。一个阳极或几个阳极为一组,根据阳极消耗程度,依次按组更换。本方法选用更换后50小时内的阳极为预报阳极效应而使用的阳极。     

上插自焙槽阳极效应预报试验

对８０ｋＡ上插自焙槽槽电阻－氧化铝浓度关系进行了研究，在此基础上通过对该模型大一实测数据的分析，确立了上插自焙槽阳极效应预报模型，并在计算机上进行了模拟实验，实验准确率７２％，平均提前量２１．６分钟，对开发上插自焙槽效应预报系统提出了建议。     

一种新式阳极

通常使用的外加电流辅助阳极都存在以下两个问题，端部效应和颈部效应，所以阳极电缆接头容易损坏，接头一旦损坏，就必须更换阳极或重新焊接连接电缆，这对埋在地下的阳极来说极不方便，通常的做法是废弃原有地床再新建，这又造成了资源浪费及投资增加。     

摆动阳极熄灭阳极效应的方法

引言铝电解槽中发生的阳极效应,可以采用把阳极压向铝水层的方法加以熄灭,这是一个普通常识。在采用电子计算机控制电解过程之前,有经验的电解车间工人也是这样做的。由于氧化铝添加量可以控制,熄灭阳极效应已能由电子计算机完成。传统的手工熄灭效     

熄灭阳极效应机理

用电场极化和电吸附观点探讨了铝电解中的熄灭阳极效应机理,并以氧化铝浓度和临界电流密度相联系,分析了熄灭自然阳极效应和诱发阳极效应成败的因果关系     

降低阳极效应系数的分析

随着阳极质量和计算机控制技术的不断提高,电解生产中阳极效应管理正在向低效应系数发展。通过对阳极效应发生的机理进行分析,结合生产实践经验,总结出了降低阳极效应系数的要求。     

降低阳极效应系数的分析

随着阳极质量和计算机控制技术的不断提高,电解生产中阳极效应管理正在向低效应系数发展。通过对阳极效应发生的机理进行分析,结合生产实践经验,总结出了降低阳极效应系数的要求。     

预焙槽熄灭阳极效应理论探讨

从电学角度探讨了铝电解阳极效应机理，又比照电容器电介质极化和短路去极化的理论，阐述了预焙槽熄灭效应各个阳极依次短路去极化机制，最后提出熄灭效应新方法。     

电镀锡机组可溶阳极设计

分析了阳极尺寸及阳极倾斜度、阳极距带钢端部距离、阳极条间距对采用可溶阳极电镀时镀层均匀性的影响。并计算了为保证带钢长度方向镀层均匀,阳极的最佳倾斜度。通过数值模拟的方法给出了阳极端部距带钢端部距离,以及阳极条的最佳间距。     

电解质对铝电解用阳极润湿性的研究

测试了熔融状态下三种不同组分的电解质对碳阳极和自制的镍铁尖晶石基金属陶瓷惰性阳极的润湿性.实验结果表明,电解质对惰性阳极的润湿性明显好于对碳阳极的润湿性,不同电解质成分对阳极的润湿角有一定影响.工业冰晶石中加入Al2O3能够改善电解质对阳极的润湿性,添加剂CaF2对提高电解质对惰性阳极的润湿性基本没有贡献.     

铝用阳极中杂质的分析与措施对策

铝电解槽的大型化,对预焙炭阳极质量提出了越来越高的要求。随着生产实践以及科学研究的不断深入,阳极中杂质的作用与影响也越来越引起人们的重视。阳极中的杂质与铝电解过程中阳极过度氧化、掉渣有直接联系,某些杂质影响到电解槽电流效率和铝的纯度等经济技术指标。所以在阳极生产过程中,对其杂质成分进行有效的监测与控制是十分有必要的。本文就铝用阳极中杂质的种类与来源,杂质对阳极的影响以及在电解过程中的作用分别进行了阐述,并对如何降低杂质含量做了探讨。     

Diagnosing the cause of incipient anodes in repaired reinforced concrete structures

The incipient anode (or halo) effect often occurs on repaired reinforced concrete structures. The diagnosis of this problem is widely reported to be macrocell activity. This diagnosis is based on very limited data. Indeed potential measurements on field structures repaired with proprietary materials have provided data that suggest that macrocell activity is not a cause of incipient anode formation. Alternative mechanisms that may cause incipient anode activity include repair/parent material interface effects, residual chloride contamination within the parent concrete, and/or vibration damage to the steel/parent concrete interface during repair area preparation.     

改性钛阳极对甲醇的电催化作用

采用热分解法制备了用于甲醇电氧化的改性钛阳极 ,用三电极体系测试了电极对甲醇的电催化氧化。循环伏安测试表明 ,甲醇氧化过程中中间产物的存在抑制了甲醇在阳极上的电催化氧化 ;稳态极化曲线则表明 ,阳极涂层中采用SnSb掺杂 ,改性钛阳极的催化活性得到显著提高 ;而往阳极涂层中加入少量Ru后 ,由于Ru遏制了PtO2 的分解 ,钛阳极催化活性有所下降。对电极制备方法加以改进后 ,可明显看出Ru促进了电极对甲醇的电催化活性。     

Effect of additive on corrosion resistance of NiFe2O4 ceramics as inert anodes

In order to improve the corrosion resistance of NiFe2O4 ceramics as inert anode, additive V2O5 was added to raw materials NiO and Fe2O3. The inert anodes of nickel-ferrite ceramics were prepared by powder metaUurgic method and the static corrosion rate in Na3AlF6-Al2O3 was determined by mass loss measurement. The effect of V2O5 on sintering property and corrosion resistance was studied. The results show that V2O5 can promote the grain to develop completely and improve sintering property. EDS results show the reaction product Ni2FeVO6 distributes along the grain boundary. The corrosion tests show that V2O5 is beneficial to improving corrosion resistance remarkably. The reasons that V2O5 can improve the corrosion resistance must be V2O5 promoting the gains to develop completely and Ni2FeVO6 distributes along the grain boundary. The stable structure can control the chemical dissolution of ceramics anode and the reinforced grain boundary can control the grain-boundary corrosion rate.     

Depolarised gas anodes for aluminium electrowinning

Consumable carbon anodes are used in the electrowinning of aluminium by the Hall-Heroult process.Emissions of CO2 may be eliminated by introducing an inert oxygen evolving anode,which however will require a higher anode potential.An alternative approach is to use a natural gas or hydrogen gas anode to reduce the CO2 emissions and lower the anode potential.Preliminary laboratory experiments were carried out in an alternative molten salt electrolyte consisting of CaCl2-CaO-NaCl at 680 °C.Porous anodes of platinum and tin oxide were tested during electrolysis at constant current.The behaviour of inert anode candidate materials such as tin oxide and nickel ferrite were also studied.     

碳烟颗粒掺杂铅基复合阳极的制备及电化学性能研究

本文采用一种快速、低成本的方法制得纳米碳材料-碳烟颗粒(C_H),并通过粉末冶金和机械合金化技术制备出铅/碳烟颗粒(Pb/C_H)复合阳极材料,利用纳米碳材料高比表面积和高催化活性等优点,提高铅基阳极的析氧电催化性。使用场发射扫描电子显微镜(FE-SEM)、傅里叶红外光谱(FTIR)、循环伏安曲线(CV)和线性扫描伏安曲线(LSV)等测试进行表征。C_H呈疏松的球链状,具有丰富的羰基和羟基功能团,是良好的电子和质子传递载体。随着C_H含量增加, Pb/C_H复合阳极的析氧超电位降低。Pb/1.5 wt.% C_H复合阳极与纯Pb和传统Pb/0.75 wt.% Ag阳极相比,其表观交换电流密度分别提高3和2个数量级。在模拟锌电积条件下,其析氧电位低于铅银合金阳极20 mV,较纯铅阳极降低133 mV,具有优异的析氧电催化活性。     

Revealing the effect of aluminum content on the electrochemical performance of magnesium anodes for aqueous batteries

Al is one of the principal alloying elements for Mg anodes. In this study, a series of Mg–Al alloys has been evaluated as anode materials for optimizing the Al addition amount in Mg anodes with the intention of improving the discharge performance in aqueous batteries. The effect of Al content on the discharge potential and corrosion resistance of the Mg anode has been investigated through microstructure characterization, electrochemical measurements in a half-cell, discharge morphology analysis, and Mg–water battery tests. The results show that the Mg–1Al alloy possesses a larger corrosion resistance during discharge, with significant increase of the anode utilization efficiency at 1 and 5 mA/cm² compared with pure Mg. However, a further increase of Al content does not continuously improve the discharge performance of the Mg anode with the decline of utilization efficiency due to the influence of the precipitated phase. This study contributes to a better understanding about the effect of Al on anodic dissolution and corrosion kinetics of the Mg anode.     

Study on effect of seawater salinity on electrochemical performance of Al anodes

In compliance with the requirements of the Shengli Oil Field of Shandong, China, the effect of seawater salinity (30‐5) on the electrochemical properties of Al‐basis sacrificial anode was studied under laboratory conditions by the method given in the Chinese National Standard GB4948‐85 (Sacrificial Anode of Al–Zn–In System Alloy) [1]. The results showed that there was no obvious effect when the seawater salinity varied from 30 to 10, but that the anodic open circuit potential, closed circuit potential and current efficiency at seawater salinity of 5 were lower than those given in the Chinese National Standard. The variation of seawater salinity must be considered while designing marine projects in estuary areas.