碳纤维表面处理对铝电解用硼化钛阴极涂层性能的影响

硼化钛阴极涂层是铝电解用可润湿性阴极材料中的一种，具有优良的抗钠渗透性和对铝液润湿性，可以有效地延长铝电解槽寿命。碳纤维是硼化钛涂层材料的增强剂之一．对硼化钛阴极涂层的性能影响很大。本文研究了不同工艺的液相碳纤维表面氧化处理法对硼化钛阴极涂层抗拉强度和粘接强度的影响。采用PTIR检测碳纤维处理后表面含氧基团的变化，寻找影响硼化钛阴极涂层性能的原因，从而达到最有效地提高TiB2阴极涂层抗拉强度和粘接强度的目的。结果表明，采用工艺(1)(10％HNO3，80℃、恒温5min．超声波、5min)对碳纤维进行表面处理最合理，处理后碳纤维表面含氧基团的含量最高．用其制备硼化钛阴极涂层的抗拉强度、粘接强度最大。     

Effect of electrolysis superheat degree on anticorrosion performance of 5 Cu/（10NiO-NiFe2O4） cermet inert anode

5Cu/(10NiO-NiFe2O4) cermet inert anodes were prepared by cold-pressing and sintering process, and the effect of superheat degree of melting K3AlF6-Na3AlF6-AlF3 on their anticorrosion performance was studied under electrolysis conditions. The results show that, the fluctuation of cell becomes small with increasing of superheat degree, which is helpful to inhibit the formation of cathodic encrustation; the concentration of impurities from inert anode in bath goes up to certain degree, but it is far smaller than those in traditional high-temperature bath. Increasing the superheat degree of melting K3AlF6-Na3AlF6-AlF3 has unconspicuous effect on the contents of impurities in cathodic aluminum. The total mass fractions of Fe, Ni and Cu in aluminum are 15.38% and 15.09% respectively under superheat degree of 95 and 195 ℃. From micro-topography of anode used view, increasing the superheat degree can aggravate corrosion of metal Cu in inert anode, and has negative influence on electrical conductivity of electrode to some extent.     

铝电解用TiB_2阴极涂层固化、炭化的升温制度

采用DTG ,DDTA等热分析手段 ,研究了高温固化、炭化过程中 ,铝电解用TiB2 阴极涂层糊料的质量和能量的变化速率 ,制定了涂层的变速固化、炭化升温制度 ;在此基础上 ,研究了升温制度对TiB2 阴极涂层性能的影响。结果表明 :变速升温制度优于匀速升温制度 ,采用变速固化、炭化升温制度所制备的涂层形变小、无裂纹 ,其抗拉强度达 3.13MPa,电阻率为 2 3.2 μΩ·m ;而采用升温速度为 10 .3℃ /h的匀速固化、炭化升温制度制备的涂层形变大、裂纹多 ,抗拉强度小 (2 .6 9MPa) ,电阻率大 (2 8.6 μΩ·m)。     

Ambient temperature cured TiB_2 cathode coating for aluminum electrolysis

1　INTRODUCTIONAluminumindustryhasbeendevelopingrapidlyinChinainrecentyears ,soderbergcellshavebeenre placedwithmodernprebakecellsinmanyaluminumsmelters,theaveragecelllifehowever ,forprebakecellsinourcountrywasonlyabout130 0d ,muchlowerthantheaveragecelllife ,i.e .above 2 5 0 0d ,forthecellsindevelopedcountries .TiB2 cathodecoating (TCC)couldbeoneofthesolutionstoreducegreatlytheopportunitytotheearlyfailureofcellsandextendthecelllifeofprebakecell[14 ] .Theconceptoftitaniumdiboride (TiB2 …     

Preparation and electrochemical characterization of activated carbons by chemical-physical activation

A process was proposed based on the combination of chemical and physical activation for the production of activated carbons used as the electrode material for electric double layer capacitor (EDLC). By material characterization and electrochemical methods, the influences of the activitation process on the specific surface area, pore structure and electrochemical properties of the activated carbons were investigated. The results show that specific surface area, the mesopore volume, and the specific capacitance increase with the increase of the mass ratio of KOH to char (m(KOH)/m(char)) and the activation time, respectively. When m(KOH)/m(char) is 4.0, the specific surface area and the mesopore volume reach the maximum values, i.e. 1 960 m²/g and 0.308 4 cm³/g, and the specific capacitance is 120.7 F/g synchronously. Compared with the chemical activation, the activated carbons prepared by chemical-physical activation show a larger mesopore volume, a higher ratio of mesopore and a larger specific capacitance. Foundation item: Project(2007BAE12B01) supported by the National Key Technology Research and Development Program of China     

铝电解用NiFe2O4-Cu金属陶瓷阳极的初步研究

采用粉末冶金技术制备了NiFe2O4-Cu金属陶瓷惰性阳极,并对其导电性能和腐蚀行为进行了初步研究.研究发现,金属Cu与NiFe2O4陶瓷润湿性差,难以实现致密化,在升温过程中,过低的表观密度能导致金属铜氧化,降低导电性能.在电解过程中,金属铜的耐蚀性好,但存在聚结现象,可能会导致电流分布不均匀,同时陶瓷基体发生非协同溶解.     

300 kA铝电解槽中焦粒焙烧过程温度场的仿真优化

使用有限元法建立了300 kA铝电解槽的焦粒焙烧三维1/4整槽模型,针对目前普遍采用焦粒均匀铺设方式,对其焦粒焙烧过程的温度分布与变化特征进行了瞬态数值仿真研究。当前的焦粒焙烧启动方式存在阴极表面温差过大、各阴极炭块随空间位置不同温度分布差异过大、端部第1至第3块阴极炭块平均温度低于900℃、阴极炭块和捣固糊升温速度过快等缺陷。提出在阴极表面从电解槽边缘向中心依次铺设电阻率递增的焦粒层的优化焙烧方案,并进行温度场仿真计算。结果表明：该优化方案可以使阴极表面温度分布更加均匀,端部第1至第3块阴极炭块表面温差比优化前降低8%以上,中间第4至第13块阴极炭块表面温差降低30%以上,阴极炭块和阴极缝糊平均升温速度降低12%,该优化方案更有利于减少电解槽的早期破损。     

导流槽阴极导杆安装方式对阴极表面电流分布的影响

将某厂现有的160kA Hall—Heroult铝电解槽改造成导流槽后，在阴极上表面和阳极底面呈斜坡状的条件下，计算了采用不同阴极导杆安装方式时阴极的电位和电流分布，即通过建立导流槽内部从阳极到阴极的一个半切片电热场模型，用有限元法分别对水平和平行于阴极斜坡两种不同导流槽阴极导杆的安装方式下阴极电位和表面电流密度分布进行了计算。结果表明，不同的阴极导杆安装方法对导流槽阴极的总电位降大小没有明显影响，但是水平阴极导杆安装更有利于阴极表面电流密度的均匀分布。     

电沉积法制备CuInSe2薄膜的组成与形貌

采电沉积法制备了CuInSe2薄膜材料，研究了制备工艺条件对材料组成、结构与性能的影响。研究结果表明：最佳的沉积电位范围为-0．6～0．8V（vsSCE）；硒化退火是获得高质量CuInSe，薄膜的必要过程，硒化退火温度应控制在440～610℃范围内；在不同沉积电位和不同电解质浓度组成溶液中，通过电沉积并在500℃下硒化退火均可获得黄铜矿结构CuInSe2多晶薄膜；沉积电位的负移会使膜层中CuInSe2的相对含量增加，晶型完善，且杂相减少；随着电解质浓度的增加，电沉积CuInSe2退火后结晶程度变好，颗粒变得粗壮，致密性也有所改善；电沉积并硒化退火后薄膜中的铜铟摩尔比受沉积电位和电解质浓度影响较大，当沉积电位为-0．7和-0．8V时，铜铟摩尔比约为1较为理想，且铜铟摩尔比的变化与电解液中CuCl2和InCl3的摩尔比变化一致。     

AlF3添加剂和焙烧温度对铝电解炭阳极过电位的影响

在实验室制备各类AlF3掺杂试验阳极，在测试其基本物理化学性能的基础上，采用“改进断电流法”进行阳极过电位测试，研究AlF3添加剂和阳极焙烧温度对阳极过电位的影响。结果表明：在一定条件下，阳极中添加AlF3既可降低阳极的空气／CO2反应活性，也可降低阳极过电位；受高温脱S等因素的影响，阳极的电化学活性及其空气／CO2反应活性并未随着焙烧温度的提高相应降低。