168kA新型阴极高效节能铝电解槽磁流体运动的数值模拟

建立了168 kA新型阴极铝电解槽磁流体运动的数学模型,对电解质与铝液交界面的流场、电解质的流场以及阴极铝液的流场进行了模拟,并对新型阴极电解槽阳极导杆等距电压降进行了测量。研究结果表明：新型阴极铝电解槽可隔断槽内铝液流动,降低槽内阴极铝液的流速。新型阴极铝电解槽铝液与电解质交界面的速度矢量和较普通阴极铝电解槽铝液与电解质交界面的速度矢量和低2～3倍,且极值分布更为均匀。新型阴极电解槽内铝液与电解质界面处的磁流体速度最大,然后以界面为中心线逐渐减小。     

石墨化阴极在400kA系列电解槽的应用

作为以电力、炭阳极、氧化铝为主力需求的高耗能电解铝企业,为积极响应国家“碳达峰,碳中和”战略目标,某公司率先通过技改措施以达到减碳降耗,采用高导电钢棒、高导电石墨化阴极炭块、强保温底层内衬材料等优化改造方案提高电能利用率,降低综合电耗。以400 kA系列铝电解槽为研究对象,探索石墨化阴极内衬在400 kA系列电解槽上的生产应用研究。石墨化阴极炭块相比石墨质阴极炭块具有更优良的导电性和导热性,可以提高电流效率和电解槽稳定性,阴极压降、平均电压、效应系数和交直流电耗明显降低,电解槽槽寿命亦有所延长,实现了电解槽内衬优化、节能降耗的目标。     

400 kA铝电解槽异形阴极炭块对阴极电压降的影响

传统阴极炭块顶部是平坦的,阴极铝液流动时几乎没有阻力。使用表面凸起的阴极炭块进行研究,目的是增加铝电解槽中铝液流动的阻力,起到减波和减少铝液流动速度的作用,以此降低水平电流密度、阴极电压和铝液流速,保障铝电解槽生产安全稳定。通过COMSOL软件进行模拟,发现随着阴极炭块表面凸起块数的增加,阴极压降和水平电流密度均呈下降趋势,其中阴极压降最大降幅为39.8 mV,水平电流密度最大降幅为2 087 A/m2,并对某铝厂400 kA铝电解槽使用异形阴极炭块后进行测试,测试结果与模拟结果一致。     

Modeling of Three-Phase Flow and Interface Deformation of Metal/Bath in Aluminum Reduction Cell With Cathode Protrusion

Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed to study the impact of the novel cathode protrusion on the molten fluid motion as well as the metal-bath interface deformation.The molten fluid motion in the aluminum reduction ceils is under the combined effect of the electro-magnetic forces(EMFs)and the gas bubbles generated at the anode.A transient inhomogeneous three-phase model(metal-bath-gas bubble)was established in order to calculate more accurate.The results indicate that the metal-bath interface deformation can be reduced significantly by the novel cathode protrusion which is beneficial to the electric energy saving.Besides,The EMFs decreases as a result of the optimizing of the magnetic field due to the novel cathode convex which is an important driving force for the deformation of the interface.In addition,large vortex in the metal flow field is break up into the small vortex by the cathode protrusion and then dissipated due to the viscous force and the hindering effect of the cathode protrusion.The quantity of the vortex as well as the strength of the vortex reduces significantly in the reduction cell with novel cathode protrusion.     

惰性可湿润性TiB2阴极材料在铝电解槽中的应用

TiB2具有熔点高,导电性好,能被金属铝液良好润湿,且能抗拒电解质和金属铝液的腐蚀与渗透,是铝电解首选的惰性阴极材料。介绍了TiB2涂层阴极、TiB2复合阴极以及TiB2陶瓷阴极材料的研究现状和惰性阴极材料在工业铝电解槽上的应用情况。     

330 kA铝电解槽异形阴极碳块对水平电流的影响

采用有限元仿真计算,对330 kA铝电解槽进行传统阴极碳块结构和异形阴极碳块结构的电场进行仿真模拟,主要对铝液中水平电流分布进行分析。研究发现,异形阴极碳块结构相对于传统阴极碳块结构能够在影响压降较小的前提下降低水平电流密度。模拟结果表明,在异形阴极碳块表面凸起中增加隔断并改变凸起角度,对降低铝液中水平电流效果明显,能够降低铝液中最大水平电流密度27.8%,平均水平电流密度34.3%,有效提升了铝电解槽电流效率。     

Theoretical Investigation of the Inclined Sidewall Design on Magnetohydrodynamic (MHD) Forces in an Aluminum Electrolytic Cell

A mathematical model of magnetohydrodynamic (MHD) effects in an aluminum reduction cell using numerical approximation of a finite element method is presented. In this numerical model, the magnetic field resulting from the cell cathode bus as well as the magnetic field from both downstream and upstream cells are included. The article outlines the three-dimensional simulation of Lorentz force distribution that results from current distribution in both the cathode bus and the cell linings. These forces are important in the side channel of the cell as the current changes its direction because of an inclined sidewall design. Thus, the present work has two main features, which are (1) a numerical model to predict Lorentz field distribution in the electrolytic cell and (2) the influence of sidewall design on current distribution in the side channel and MHD forces. The model predicts that the magnitude of Lorentz force is at its maximum near the sidewall (i.e., along the side channel). The radial component of the Lorentz force creates a concentric rotational flow field, whereas the radial component is responsible for the metal “heave.” Results are obtained for different inclination angles (θ = 50 to 64 deg) of the sidewall insulation and at different pot-line currents (140 kA to 180 kA). The direction of the resultant Lorentz force is greatly influenced by the slope of the sidewall and is important to the convective flow of metal and bath in the cell.     

曲面阴极铝电解槽结构改进及等温线温度测量的分析研究

介绍了针对300 k A曲面阴极铝电解槽生产中存在的问题,采取优化改进电解槽结构,开展等温线温度测量分析研究,表明改进后的曲面阴极电解槽能满足安全、平稳、高效生产的要求,其工艺技术及经济指标达到了国内先进水平。     

40 kA制钠电解槽流场的模拟研究

电解质在阳极气泡和阴极钠液浮力的作用下在制钠电解槽内循环流动,是典型的气—液—液三相流动。使用FLUENT软件建立40kA制钠电解槽三维流场的数学模型,通过计算得到了电解槽内气泡、钠液的浓度和速度分布情况,以及熔盐的流场分布图。     

Simulation of the Aluminum Electrolysis Process in a High-Current Electrolytic Cell in Modern Software

Metallurgist - A three-dimensional nonstationary model of a 600 kA electrolytic cell is described. The mathematical model describes the electrolysis processes occurring in the cell. The assumptions...     

电解铝液铸轧生产3003阴极铝箔坯料质量控制

分析了用电解铝液直接生产3003阴极铝箔坯料的质量问题以及铸轧板质量缺陷的影响因素,阐述了生产铸轧坯料的原辅材料、熔体处理、晶粒细化、板形控制、铸轧辊表面质量的控制措施,提高了铸轧坯料的质量,有效地控制了阴极铝箔的针孔数量和偏析.     

高温焙烧法处理铝电解废旧阴极炭块

废旧阴极炭块的无害化与资源化已成为制约铝电解行业绿色可持续发展的资源环境难题。利用高温焙烧法处理废旧阴极炭块,基于不同粒度废旧阴极炭块的工业成分和浸出毒性,探索骨料粒度和焙烧温度对高温焙烧处理效果的影响。结果表明,随着骨料粒度的增大和焙烧温度的提高,回收炭材料碳含量逐渐提高,可溶性氟化物含量大幅降低。在最佳高温焙烧参数下,回收炭材料的碳含量由65.21%提高至94.52%,F^-浸出浓度由4 018.55 mg/L降至7.63 mg/L。同时利用化学沉淀法对气态冷凝产物进行固化处理,提取高纯度的CaF₂产品,避免高浓度含氟烟气二次污染。通过高温焙烧法处理铝电解废旧阴极炭块具备技术可行性。     

Simulation of the Fluid Flow-Related Phenomena in the Electrolyte of an Aluminum Electrolysis Cell

A full-scale water model and mathematical simulation were used to study the fluid flow-related phenomena in a water model of an aluminum electrolysis cell. The time-dependent, multiphase fluid flow model was developed to represent the complex transient flow in the electrolysis bath. The accuracy of the mathematical model was validated by the ink dispersion and laser doppler velocimetry measurements in the water model. The shape, motion, release frequency of large-size bubbles, the fluid flow pattern, and the electrolyte–metal interface were predicted by the mathematical simulation. The design and operation of the anode were discussed, including the effect of the anode edge corner shape, the presence of a tilted bottom angle, and the magnitude of applied current density. The results indicated that coupling using a curved corner, with slot and with tilted angle at the anode, is effective for the release of bubbles and for the stability of the electrolyte–metal interface.     

500kA电解槽用铝电解多功能机组的开发与应用

针对大型预焙阳极铝电解槽电流强度不断增大的趋势,重点阐述本单位最新研发的、应用在500 kA电解槽结构中的铝电解多功能机组之技术创新点;介绍了在该机组中应用的国内首创、具有自主知识产权的几种主要结构,对类似产品的设计与改进创新具有重要的指导意义。     

铝电解废槽衬工艺矿物学分析

铝电解废槽衬中含较多的有价资源（碳和电解质等）,但因其成分复杂、有用矿物紧密共生,回收时存在有用矿物回收率不理想、纯度低、处理成本高等问题,限制了废槽衬的回收利用。采用XRF、XRD、SEM-EDS、MLA等检测手段,对某铝电解废槽衬样品进行完整、详细的工艺矿物学分析。结果表明：废槽衬样品中碳的含量约占67%,此外还含有碳化硅、冰晶石、β-氧化铝、霞石、氟化钠、水碱、树脂及少量非晶态物质。可回收矿物包括碳、氟化钠及冰晶石,其中碳含有较多杂质且内部存在β-氧化铝（NaAl7O11）和大量微细粒包裹体,是造成碳回收困难的主要原因;氟化钠主要以颗粒状的形式与微细粒氟化钙紧密共生,使净化电解质的工艺变得复杂;冰晶石则以不规则粒状形式嵌布于碳内部,此外少数冰晶石与氟化钙或氟化钠紧密共生或连生。     

铝电解槽阴阳极热力分析仿真研究

铝电解是高能耗行业,节能降耗一直是铝电解行业致力研究的课题。借助大型通用有限元分析软件ANSYS,建立铝电解槽阴阳极热结构模型,对铝电解槽阴阳极的热场、应力场进行了数值仿真研究,为降低阴阳极接触电压提供数据支持。仿真结果表明：铝电解槽阴阳极的高温部分集中在阳极炭块底部和阴极中部。而应力集中在阴极底部接触部分,应力最小的地方在阳极炭碗部分。     

电解槽内异型凸台对电解质/铝液界面波动的影响

针对铝电解槽内电解质/铝液界面的波动现象,基于计算流体动力学(CFD)的方法建立了铝电解槽内电解质/铝液两相流体流动的数学模型.使用Fluent软件的流体体积自由面跟踪法和自定义函数,研究了阴极凸台对电解质/铝液界面波动的影响.结果表明,异型凸台的加入使得两相界面的波动幅度降低了17.2%,但凸台的存在同时也使得熔体对侧部槽帮冲刷增强.     

“非平面阴极”槽生产过程的控制策略

根据"非平面阴极"对电解槽铝液波动的抑制原理和效果,提出对该类槽型主要技术参数和过程的控制,并针对存在的缺陷,对研发方向给出一定的参考意见。     

铝电解槽阳极极距构成模型及工艺能耗

计算了普通电解槽生产中通常的阳极极距,提出了阳极极距“三层构成模型”及“极限阳极极距”概念,用此理论对目前研究中的低槽电压生产仍能获得较好生产指标进行了解释,并展望了铝电解工艺能耗能达到的可能范围：在阳极电流密度为0．8A／cm^2左右时,电解直流电耗可达到9500kWh／t—Al左右．     

电解铝槽电阻模型分析与计算方法的研究

重点研究影响电解铝槽电阻的主要因素,分析其与槽电阻之间的具体关系,通过研究确定以最小二乘曲线拟合方法建立槽电阻数学模型,并以青铜峡铝业某铝厂的400 kA电解槽为应用实例,利用电解车间240台电解槽的实际运行数据使用最小二乘方法建立数学模型,并与差分方程方法进行比较,结果表明了最小二乘建模方法的有效性和准确性.