导流型铝电解槽用复合硼化钛阴极制备方法

本发明在用振动成型Ti段阴极碳块砌筑好的导流型铝电解槽的阴极内衬上，涂覆多层不同TiB2含量的碳胶TiB2涂层浆料，利用铝电解焦粉焙烧工艺产生的热量炭化涂层，在线制备导流型铝电解槽用金属铝液可润湿性TiB2阴极。     

铝电解阴极新技术

在振动成型生产阴极炭块过程中 ,直接把TiB2复合材料和炭块基体振动压制成为一体化复合阴极 ,经过焙烧 ,按常规方法在 75kA预焙电解槽上进行砌筑和工业试验 ,两年来试验槽生产稳定 ,炉底干净 ,炉膛规整 ,易于操作维护 ,TiB2 复合层不脱落 ,不起层 ,效果良好。试验槽电流效率提高0 .9% ,直流电耗吨铝降低 1 88kWh,炉底压降也有所降低 ,原铝质量毫无影响。     

导流型铝电解槽用复合硼化钛阴极制备方法

导流型铝电解槽用复合硼化钛阴极制备方法。本发明在用振动成型TiB2阴极碳块砌筑好的导流型铝电解槽的阴极内衬上，涂覆多层不同TiB2含量的碳胶TiB2涂层浆料，利用铝电解焦粉焙烧工艺产生的热量炭化涂层，在线制备导流型铝电解槽用金属铝液可润湿性TiB2阴极。本发明提高了导流型铝电解槽可润湿性阴极的服务寿命，所生产的产品成本较低，并能完全与金属铝液润湿，符合导流型铝电解槽的要求，可以达到节能的目的。在线制备可润湿性梯度功能复合TiB2阴极，不需另外添加设备，施工费用低，应用方便。     

石墨化阴极炭块的性能及在大型铝电解槽上的应用

介绍了我国自行研制开发的石墨化阴极炭块的技术指标及在300 kA铝电解槽上进行的工业试验.试验表明石墨化阴极可以降低炉底阴极压降90mV,提高电流效率1.5%以上,900天左右可收回所增加的大修成本,是大型铝电解槽筑炉内衬材料今后发展的主要方向.     

采用电接触模型的铝电解槽阴极电压降分析

320kA和350kA预焙阳极电解槽的阴极电压降(cathode voltage drop,简称CVD)约占槽电压的7%～9%.这一比例虽小,但对电解槽的整体能耗有着重要意义.使用有限元法建立了非线性电接触模型并用于分析CVD.该模型能够考虑阴极碳块类型、结构及伸腿生长或槽底沉淀对CVD的影响.计算结果表明:模型预测的电场分布与工业电解槽上的测量数据和文献数据吻合较好;阴极碳块由半石墨质碳块转变为石墨化碳块,阴极电压降约减少70mV;就电压降而言,采用两个直通阴极钢棒的阴极结构设计略优于采用两个内嵌阴极钢棒的结构设计;伸腿增长或者炉底有沉淀产生,CVD会增大.     

石墨化和全石墨质阴极材料在350kA铝电解系列中的应用

结合铝电解生产实际,在阴极压降、电压、铝水平、电流分布、炉底钢板温度、电流效率和电耗方面对比了石墨化和全石墨质阴极材料在350kA铝电解系列中的应用情况,用石墨化阴极的电耗比用全石墨质阴极的电耗低。     

超低能耗铝电解技术研究和经济效益分析

在某SY500电解系列中选取若干电解槽,进行不同材料和不同阴极组装方式的对比试验,并对3年的试验结果进行技术和经济效益分析,找到了指标最优、经济效益最高的技术方案,即采用高导电钢棒和石墨化阴极浇铸技术。试验结果显示,此方案相对于采用原内衬设计形式的对比槽,炉底压降降低了169 mV,电流效率提高了1. 56%,吨铝直流电耗降低了569 kWh,营业收入最高,达到了1 545. 49万元。     

石墨化阴极炭块的性能及在大型铝电解槽上的应用

介绍了我国自行研制开发的石墨化阴极炭块的技术指标及在300kA铝电解槽上进行的工业试验。试验表明：石墨化阴极可以降低炉底阴极压降90mV，提高电流效率1．5％以上，900天左右可收回所增加的大修成本，是大型铝电解槽筑炉内衬材料今后发展的主要方向。     

冷捣糊在石墨化阴极炭块上的应用

随着国家对铝行业节能降耗的要求,电解铝企业对阴极炭块的性能要求越来越高,从普通的无定型炭块,石墨质炭块到现在大规模使用的石墨化炭块.铝用阴极导电性得到很大提高,阴极压降降低明显.大多铝厂陆续在新开槽和大修槽上使用石墨化程度高的阴极炭块,从而获得好的经济效益.但随之而来的问题是石墨化阴极炭块对应的各种糊料的要求也要相应的变化,才能更好地防止启动漏炉破损,提高槽寿命,发挥石墨化阴极炭块的优势.     

半石墨质阴极炭块在铝电解槽上的应用

通过对普通炭块的理化指标和半石墨质阴极炭块的理化指标的对比,介绍了在铝电解槽上使用半石墨质阴极炭块,有利于延长槽寿命,提高电流效率,降低炉底压降,节约电能。     

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。     

Colloidal Alumina-bonded TiB2 Coating on Cathode Carbon Blocks in Aluminum Cells

Self-propagating high-temperature synthesis (SHS) with reduction process was used to fabricate TiB2 powder from TiO2-B2O3-Mg system. The colloidal alumina-bonded TiB2 paste was prepared and coated on the cathode carbonblocks. Various properties of the baked paste such as the corrosive resistance, thermal expansion and wettability were tested. Experimental results showed that the colloidal alumina-bonded TiB2 coating could be well wetted by liquid alum inum; and the thermal expansion coefficient of the coated material was 5.8× 10 6 ℃ -1 at 20-1000℃, which was close to that of the traditional anthracite block cathode (4× 10 6 ℃ 1); the electrical resistivity was 8 μΩ·m at 900℃ when the con tent of alumina in the coated material was about 9% in mass fraction. In addition, some other good results such as sodium resistance were also reported.     

Fabrication of vacuum-arc Ti-Al-N coatings using multicomponent SHS-compacted cathodes

The results of experiments on the deposition of vacuum-arc Ti-Al-N coatings using aluminum-containing pressed cathodes based on nonstoichiometric titanium carbide TC_0.5 are presented. The composition and morphology of coatings are investigated using electron probe microanalysis and scanning electron microscopy. Hardness and elasticity modulus were determined using the nanoindentation method. It is established that carbon is absent in the coating, while the fraction of aluminum in it decreases compared with its content in the cathode material. A superhard coating with nanohardness H = 59 GPa and the Young modulus E = 475 GPa is obtained from the cathode with the calculated composition TiC_0.5-30%Al. By the ratio of hardness to the elasticity modulus, which equals H/E = 0.124, this coating is an amorphous-crystalline material. When using cathodes based on refractory nonstoichiometric titanium carbide, the content of the drop phase in coatings substantially lowers with no separation of the plasma flow. In general, the application of multicomponent SHS-compacted cathodes based on nonstoichiometric titanium carbide TiC_0.5 makes it possible to fabricate superhard nanocrystalline coatings according to the standard technology using a serial vacuum-arc installation.     

TiB_2惰性阴极材料的特性与工程化实验研究

针对现代大型金属铝惰性材料的技术发展 ,重点论述二硼化钛惰性阴极材料的特性和作用机理 ,叙述了二硼化钛粉体制备、二硼化钛及其复合材料的涂层技术 ,提出厂混捏—成型可湿性阴极的工业实验方案     

Composition,structure, and properties of SHS-compacted cathodes of the Ti-C-Al-Si system and vacuum-arc coatings obtained from them

The phase composition, structure, and properties of self-propagating high-temperature synthesis (SHS)-compacted materials of the Ti-C-Al-Si system are investigated. It is shown that metal-like titanium compounds can be used as cathodes for vacuum-arc evaporators. The coatings fabricated from SHS cathodes are single-phase and represent cubic titanium nitride of the (Ti, Al, Si)N composition. The volume of a microdrop phase in them is smaller by a factor of 2.5–3.0 as compared with TiN, while their microstructure is not fragmented into low-strength columnar elements; the CSR size is twice smaller than that of titanium nitride. Being approximately identically hard, the (Ti, Al, Si)N coatings substantially surpass TiN coatings in elastic and plastic failure resistance due to the lower elasticity modulus. When milling the tungsten-copper alloy, the hardness of hard-alloy milling cutters with the (Ti, Al, Si)N coating is higher by a factor of 2.4 than with the TiN coating fabricated from the titanium cathode with the magnetic plasma flow separation.     

复合溶胶凝胶法制备TiB2可湿性阴极涂层

针对铝工业阴极和阳极碳电极以及侧壁耐蚀导电二硼化钛陶瓷涂层技术,研究用非有机溶剂湿化学陶瓷清洁制造技术,替代沥青粘结工艺。通过氧化铝胶体中的纳米粒子,分散清洁二硼化钛,形成均匀陶瓷悬浮涂料,经刷涂或喷涂形成TiB2涂层。对二硼化钛与工业铝电解体系熔体、气相的化学侵蚀性进行了理论计算,分析了炭基TiB2涂层的耐蚀性、捕获钠的机理。用SEM分析了二硼化钛涂层断面,二硼化钛在氧化铝胶粒的分散下,迁移、渗入多孔的碳基底,在热处理条件下,与基底间形成很强的化学键合,可形成微米至数毫米厚、无龟裂的涂层。涂层的电性能检测结果表明,浆料中氧化铝胶体含量为 10%Wt时电阻率较低,电阻率随烧结温度升高而降低。     

金属钛表面Na2B4O7-Al熔盐渗硼

分别以熔融Na2B4O7和Na2B4O7+Al为渗硼剂,在钛金属表面渗硼,以期获得含TiB2和TiB双层结构的硼化层。通过X射线衍射(XRD)分析涂层表面的物相结构。结果表明,单独以Na2B4O7作为渗硼剂时基体表面没有生成硼化物,主要生成Na2Ti4O8。在Na2B4O7中添加10%Al(质量分数)后,钛表面有明显的TiB2和TiB生成。温度升高有利于TiB2的生成,但会抑制TiB的生成。热力学分析表明,与单独用Na2B4O7做渗硼剂相比,以Na2B4O7+Al为渗硼剂时生成活性B原子的反应趋势较大,因而活性B原子的浓度较高。动力学分析表明,低温时由于B原子在TiB相中的扩散速度大于其在TiB2相和Ti相中的扩散速度,因而有TiB和TiB2生成。高温时由于B原子在Ti相中的扩散速度大于其在TiB相中的扩散速度,因而主要生成TiB2。     

铝电解用TiB2/Al2O3复合阴极的烧结与性能研究

以氧化铝溶胶为粘结剂,采用冷压烧结法制备出铝电解用TiB2/Al2O3复合阴极材料,研究了烧结温度、烧结时间和溶胶添加量对复合阴极相对密度、电阻率和抗压强度的影响。结果表明:烧结温度的提高能够增加复合阴极的相对密度,同时有利于降低复合阴极电阻率。1 400℃烧结的复合阴极相对密度可达93.83%,电阻率最低为0.56μΩ.m。随着烧结时间的延长,复合阴极的电阻率先降低后增加。烧结时间为5 h时复合阴极电阻率最低,为0.72μΩ.m。当溶胶含量为25%,1 400℃烧结5 h时,复合阴极材料性能最佳,其电阻率可达0.72μΩ.m、抗压强度为38.70 MPa。     

熔盐体系中电沉积制备TiB2镀层的研究现状

介绍了熔盐体系中电沉积制备TiB2镀层技术中熔盐的选择、电镀工艺和参数的选择，概述了不同熔盐体系中B离子、Ti离子在阴极沉积的电化学机珲以及TiB2的合成机理，论述了TiB2惰性阴极在铝电解工业中的研究现状，最后分析了熔盐体系中石墨电极上制备TiB2镀层的可行性。     

A porous titanium diboride composite cathode coating for Hall-Héroult cells: Part I. Thin coatings

The mechanical, electrical, and electrochemical properties of a porous cathode coating, made by compositing titanium diboride powder and colloidal alumina, are described. Such coatings are expected to be used on the carbon cathodes employed in Hall-Héroult cells. The properties of the composite coating are compared with uncoated carbon cathode reference samples. The bonding properties of the coating with the carbon are also examined. The sodium trapping mechanisms of the coating are explored in this article. An earlier version of this article appeared in TMS Light Metals 1996 Proc., edited by W. Hale. This previous article is cited herein in Ref. 28.