LOW TEMPERATURE ALUMINUM ELECTROLYSIS IN NaF-AlF3-BaF2-CaF2 BATH SYSTEM

１ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｎｃｅｔｈｅＨａｌＨｒｏｕｌｔｐｒｏｃｅｓｗａｓｉｎｖｅｎｔｅｄｏｎｅｈｕｎｄｒｅｄｙｅａｒｓａｇｏ,ｉｔｈａｓｂｅｎｔｈｅｏｎｌｙａｌｕｍｉｎｕｍｐｒｏｄｕｃｔｉｏｎｍｅｔｈｏｄｉｎｔｈｅｗｏｒｌｄ［１］．Ｔｈｅ...     

电解废旧铝合金回收铝的电流效率(英文)

研究在AlC13-NaCl熔融盐体系中进行电精炼废旧铝合金回收金属铝。以铝合金为阳极,通过直流电沉积在铜阴极上得到铝涂层。在170°C、电流密度100 mA/cm2下电解4 h,得到的沉积物铝的纯度大约为99.7%,电流效率为44%~64%,每千克铝消耗电能3~9 kW·h。探讨阴极电流密度、电解质成分和电解时间及温度等对铝沉积电流效率的影响。结果表明:在AlCl3和NaCl摩尔比为1.3~1.9时,AlCl3和NaCl摩尔比对电流效率的影响很小,升高电解温度有利于提高电流效率;但是延长电解时间或增大电流密度会导致电流效率降低。电流效率的降低主要是由于沉积的铝呈现枝状晶或粉化而易从阴极上脱落到电解质中所致。     

控制AlF3投入量形成炉帮的方法

通过加大AlF3投入量来降低槽温,反复在低槽温环境中迅速减少AlF3投入量快速提高分子比,同时辅以调低设定电压、增加铝水平高度或减少电解质高度等手段,控制电解质结晶形成炉帮,对不规整炉帮进行进一步的修复和加厚,使其在现有的生产工艺稳定生产的前提下,进一步提高电流效率.     

Coupled heat/mass-balance model for analyzing correlation between excess AlF3 concentration and aluminum electrolyte temperature

The influence of aluminum electrolyte component on its temperature is an important issue within the field of aluminum reduction with pre-baked cells. The characteristic correlation between excess AlF3 concentration and aluminum electrolyte temperature was explored through the modeling of heat and mass transfer processes in industrial pre-baked aluminum reduction cells. A coupled heat/mass-balance model was derived theoretically from the mass and energy balance of an electrolysis cell, and then was simplified properly into a practical expression. The model demonstrates that if environmental temperature and Al2O3 concentration keep constant, the excess AlF3 concentration decreases with the aluminum electrolyte temperature linearly and its decrease rate is dependent on the heat transfer property of aluminum electrolyte, side wall and cell shell. Secondly, experiments were conducted on site with two industrial cells in an aluminum electrolysis plant. Excess AlF3 concentration and aluminum electrolyte temperature were obtained simultaneously together with other parameters such as Al2O3, CaF2, MgF2 and LiF concentrations. Results show that the maximum absolute error between the tested value and the calculated value of excess AlF3 concentration using the proposed model is less than 2%. This reveals that the coupled heat/mass-balance model can appropriately characterize the correlation between excess AlF3 concentration and aluminum electrolyte temperature with good accuracy and practicability.     

Preparation of Al-Sr Master Alloy in Aluminum Electrolysis Cell

1 ＩｎｔｒｏｄｕｃｔｉｏｎＡｌ Ｓｒｍａｓｔｅｒａｌｌｏｙｉｓａｋｉｎｄｏｆｍｏｄｉ ｆｉｅｒｓｕｎｄｅｒｄｅｖｅｌｏｐｍｅｎｔ .Ｉｔｈａｓｍａｎｙａｄ ｖａｎｔａｇｅｓｏｖｅｒｏｔｈｅｒｍｏｄｉｆｉｅｒｓ .Ｉｔｓｍｏｄｉｆｙｉｎｇｂｅｈａｖｉｏｒｃａｎｌａｓｔｆｉｖｅｔｏｓｅｖｅｎｈｏｕｒｓａｎｄｆｏｒｓｅｖｅｒａｌｔｉｍｅｓ ,ａｎｄｌｉｔｔｌｅｃｏｒｒｏｓｉｏｎｉｓｏｂ ｓｅｒｖｅｄｄｕｒｉｎｇｔｈｅｍｏｄｉｆｉｃａｔｉｏｎｃｏｕｒｓｅ[1 ].Ｔｈｅｒｅｆｏｒｅ ,ｉｔｉｓｃｏｍｍｏｎｌｙｕｓｅｄｉ…     

熔盐电解CuO/SiO2制备铜硅合金

以质量比为1∶1的CuO、SiO2混合氧化物为反应原料,熔融的CaCl2-NaCl为电解液,在槽电压2.8 V、电解温度700℃下,电解5 h制备得到Cu3Si/Si复合物。热力学计算结果表明,在700℃下,CuO优先被电解还原生成单质Cu,SiO2在SiO2/CaCl2-NaCl电解质/Cu三相反应界面进行电解还原,生成的单质Si与Cu自发进行合金化反应,生成Cu3Si。新生成的Cu3Si合金作为新的导电集流体,推进SiO2的电解反应。电解产物Cu3Si/Si的微观形貌为粒径在0.1~1.9μm之间的多孔颗粒堆积,Si颗粒覆盖在Cu3Si合金颗粒表面。     

Electrolytic preparation of Al-Ca master alloy on liquid Al cathode

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｓａｎｅｗｌｙｄｅｖｅｌｏｐｉｎｇｓｕｐｅｒ ｐｌａｓｔｉｃａｌｕｍｉｎｕｍａｌｌｏｙ ,Ａｌ Ｃａａｌｌｏｙｈａｓｎｏｔｏｎｌｙｇｏｏｄｐｌａｓｔｉｃｉｔｙ ,ｂｕｔａｌ ｓｏｇｏｏｄｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｙ ,ｇｏｏｄｗｅｌｄｉｎｇｐｒｏｐｅｒｔｙａｎｄｓｔｒｏｎｇｒｅｓｉｓｔａｎｃｅｏｆｃｏｒｒｏｓｉｏｎａｆｔｅｒｂｅｉｎｇｆｏｒｍｅｄ .Ｔｈｅｒｅｆｏｒｅ ,ａｌｏｔｏｆｍｅｔａｌｌｕｒｇｉｃａｌｓｃｉｅｎｔｉｓｔｓｈａｖｅｄｅｖｏｔ ｅｄｔｏｔｈｅｒｅｓｅａ…     

Ni-Fe-Cu惰性金属阳极的抗氧化和耐蚀性能

对Ni-Fe-Cu合金的抗氧化和耐熔盐腐蚀性能进行了研究.结果显示, 该合金的氧化动力学曲线符合抛物线规则.静态电解质中的溶解腐蚀速率随温度的增高和NaF与AlF3的摩尔分子比的降低而增大.在不同电解条件下, 组成为NaF-AlF3-NaCl-CaF2-Al2O3的电解质体系中电解时, 该阳极周围产生大量气泡, 槽电压在3.6～4.2之间波动, 阳极的电解极化腐蚀速率随电解质中氧化铝浓度的增高、温度的降低而减小, 产品铝的纯度达到97%～98%.     

Na_2SiO_3浓度对6063铝合金微弧氧化层组织与性能的影响

采用X射线衍射仪(XRD)、扫描电镜(SEM)、显微硬度计、摩擦磨损试验机等手段研究了不同电解液浓度对6063铝合金微弧氧化陶瓷涂层的相组成、微观结构、显微硬度、耐磨性能等的影响。结果表明:电解液浓度对涂层的性能有着较大的影响。电流密度和处理时间一定的条件下,当Na2SiO3的浓度小于9 g/L时,随着电解液浓度的增大,成膜速率有所提高,涂层中α-Al2O3与γ-Al2O3相的衍射峰明显增强,涂层与基体的结合力增大,且涂层的硬度和耐磨性也有很大的提高;但是当Na2SiO3的浓度大于9g/L时,涂层的硬度等性能基本不再变化,甚至有所下降。     

Electrolytic properties and element migration in Ni-TiB_2/Al_2O_3composite cathode

With alumina sol as binder and Ni metal as sintering aids,the Ni-TiB_2/Al_2 O_3 composite cathode material for aluminum electrolysis was prepared by coldpressed sintering.The mechanical properties of the composite cathode material were measured.Its electrolytic properties were identified by a 20-A electrolysis test.Cathode samples before and after electrolysis test were measured by energy-dispersive spectroscopy(EDS).The migration behavior of various elements in the electrolysis process was studied by phase analysis.The result shows that Ni metal can effectively fill the gap between the aggregate during the sintering process,which can improve the sintering density of the composite cathode material significantly.The voltage of the 20-A electrolysis test is stable.The impurity of aluminum liquid is 0.42%.The aluminum liquid can wet the cathode surface effectively,and the Ni-TiB_2/Al_2 O_3 composite is an ideal wettable cathode material.In the process of electrolysis,the alkali elements in the electrolyte penetrate the electrode,where K goes deeper than Na.Al generated on the cathode surface will also penetrate the cathode through the gap of the composite material,while Ni in the electrode will spread into the aluminum liquid layer.     

一种含氟化镁电解质体系的温度、密度和导电度论证

本文对一种在生产中使用的含镁铝电解质体系的温度、密度、导电度利用经验公式进行了论证。通过论证得出如能通过技术手段和管理手段对电解质中各成份含量进行精细控制，电解生产可以在较低温度下高效运行；该电解质体系和铝液的密度差在一些情况下较小，生产中注意提前调控；该电解质体系和低分子比高氟化钙电解质体系的导电度相当。     

ELECTROCHEMICAL DETERMINATION OF CURRENT EFFICIENCY IN ALUMINIUM ELECTROLYSIS

ＥＬＥＣＴＲＯＣＨＥＭＩＣＡＬＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＣＵＲＲＥＮＴＥＦＦＩＣＩＥＮＣＹＩＮＡＬＵＭＩＮＩＵＭＥＬＥＣＴＲＯＬＹＳＩＳＴｉｅ；Ｊｕｎ（ＭｅｔａｌｌｕｒｇｉｃａｌＥｎｇｉｎｅｅｒｉｎｇＩｎｓｔｉｔｕｔｅ，ＮｏｒｔｈＣｈｉｎａＵｎｉ...     

Results from 100 h electrolysis testing of NiFe2O4 based cermet as inert anode in aluminum reduction

1 Introduction Since the Hall-Héroult process was applied in aluminum production, an inert anode was always the target that the aluminum industry was seeking for in the new technology field[1]. Some selection criteria have been defined in order to ident…     

铝阳极氧化膜冷封孔机理研究——Ⅰ.冷封孔氧化膜的组成结构

应用X-射线衍射、红外光谱、热重和差热分析对铝在硫酸中阳极氧化后经BY02封孔剂冷封孔处理的氧化膜组成结构进行了研究,结果表明:铝的阳极氧化膜主要由无定形氧化铝组成,膜中含有SO_4~(2-);在冷封孔反应过程中形成了AlOOH、Ni(OH)_2和AlF_3等产物。文中还讨论了冷封孔反应机理。     

偏硼酸钠体系铝合金仿木纹交流电解工艺

在普通偏硼酸钠－硼酸仿木纹电解液的基础上,通过添加碳酸钠作为刻蚀剂,添加磷酸钠作为增粘剂,得到了一种新型的偏硼酸钠体系仿木纹电解液。分析讨论电解液组成及工艺条件对仿木纹电解效果的影响后,发现碳酸钠和磷酸钠质量浓度是主要影响因素,工艺条件的影响是相互制约的。该新工艺具有电解液稳定,获得的木纹逼真,操作简便等特点     

Yb_2O_3掺杂对15(20Ni-Cu)/(NiFe_2O_4-10NiO)金属陶瓷性能的影响

采用冷压-烧结技术制备NiFe2O4-10NiO基金属陶瓷材料;通过对烧结体的显微结构和物相组成、电导率、电解试样的表层形貌、电解质和阴极铝的杂质增量等的分析检测,研究Yb2O3掺杂对15(20Ni-Cu)/NiFe2O4-10NiO金属陶瓷致密度、导电率和耐腐蚀性能的影响。结果表明:1 300℃烧结的0.5%Yb2O3-15(20Ni-Cu)/(NiFe2O4-10NiO)金属陶瓷具有较好的性能,相对密度为98.53%,960℃时的电导率为53.06 S/cm,电解腐蚀后金属腐蚀层厚度为20~30μm,总杂质增量为0.079 g。     

卷筒式铝板材生产PS版电解原理探讨

详细叙述了卷筒式铝板材生产PS版电解基本原理,提出电解铝板材形成砂目过程实际是一个交流电加速原电池腐蚀反应过程的观点.影响PS版砂目结构的因素有交流电的电流密度、电压、波形、频率、电解液成分及其浓度和温度等. 还分析了电解过程中的能耗结构及其计算公式.     

Preparation of high-purity indium by electrorefining

The application of indium requires high purity indium as material, and the high purity indium has been prepared by electrorefining. The selection and preparation of electrolyte in electrorefining indium were investigated,and the effect of component of electrolytic solution on electrolytic refining was also studied. Compared with electro-lyte of InCl3-HCl, electrolyte of In2(SO4)3-H2 SO4 has higher stability and lower corrosivity, electrolytic solution can be heated at low temperature, and bath is open and simple, which makes operation more convenient. The results show that the voltage can be kept at 0. 3-0.5 V, and the content of indium can exceed 99. 999% when the contentof indium(Ⅲ) ion and sodium chloride are 80-120 g/L. The bench-scale test of electrolysis was carried out, and the product of indium reaches the national standard of 99. 999% high purity indium.     

Corrosion behavior of Cu-Ni-Ag-Al alloy anodes in aluminium electrolysis

The behavior of Cu-Ni-Ag-Al alloy used as anode for aluminum electrolysis was directly visualized in a two-compartment see-through cell during electrolysis, and its performances were tested at 850℃ in acidic electrolyte molten salts consisting of 39.3%NaF-43.7%AlF3-8%NaCl-5?F2-4%Al2O3 for 40 h in a laboratory cell. The results show that nascent oxygen oxidizes the anodic surface to form oxide film at the beginning of electrolysis. X-ray diffraction analysis of alloy surface show that the oxide film on the anodic surface consists of CuO, NiO, Al2O3,CuAl2O4 and NiAl2O4. However, SEM image shows the oxide film is porous, loose and easy to fall into electrolyte and to contaminate aluminum. The corrosion mechanism of metal anodes was analyzed.     

电解铝炭素阳极消耗研究评述

电解铝过程中，炭素阳极的实际消耗远高于其理论消耗，直接影响原铝的生产成本。本文在分析铝用炭素阳极消耗机理的基础上，评述了阳极生产和电解铝生产中的诸多因素对炭素阳极消耗的影响，这些因素包括：阳极电流密度、石油焦煅烧温度、阳极焙烧温度、电解槽操作温度、阳极硫含量、阳极金属杂质、残极和灰分、阳极添加剂、电解质添加剂、阳极配方的沥青用量和阳极保护措施等。