摘要
采用粉末冶金法在3种温度下制备了60Ni40Fe,10Cu50Ni40Fe和65Cu25Ni10Fe3种合金,并分别作为惰性阳极在700℃钾冰晶石低温体系(CR=1.3)中进行5A级的实验室规模铝电解,电解电流密度为0.5A.cm-2,电解时间为8.0h。3种NiFe合金阳极体系电解过程相差明显,不含有Cu的60Ni40Fe合金阳极电解过程槽电压波动较大,原铝的纯度仅为91.23%;65Cu25Ni10Fe合金阳极电解过程中槽电压比较平稳,平均槽电压为3.422V,但是原铝中杂质Cu含量达到4.5%;10Cu50Ni40Fe合金阳极电解过程槽电压比较平稳,平均槽电压为3.829V,原铝的纯度可达99.74%,是3种合金中电解性能最优的阳极。采用XRD,SEM和EDS等手段分析合金阳极电解后表面组成、结构及形貌的变化情况。表明3种NiFe合金阳极表面氧化膜成分相差明显,60Ni40Fe和65Cu25Ni10Fe合金阳极表面分别生成了NiO和Ni0.8Cu0.2O,结构比较疏松。10Cu50Ni40Fe合金阳极表面氧化膜的元素扫描表明各元素为层状分布,在合金基体表面生成了比较致密的Ni1.25Fe1.85O4,Ni1.25Fe1.85O4对合金阳极具有很好的保护作用,抑制了熔盐及氧对合金基体的腐蚀。
Three types of alloy,such as 60Ni40Fe,10Cu50Ni40Fe and 65Cu25Ni10Fe,were prepared by using powder metallurgic method at three different temperatures.The three types of alloy were employed as inert anodes for aluminum electrolysis in potassium cryolite molten salt system（CR=1.3） at 700 ℃.The electrolysis was carried out for 8.0 h with a current density of 0.5 A·cm-2.The electrolysis process for the three NiFe alloy anode systems differed from each other distinctly.For 60Ni40Fe alloy anode without Cu,the cell voltage varied greatly in the electrolysis process and the purity of primary aluminum was only 91.23%.For 65Cu25Ni10Fe alloy anode the cell voltage varied inconspicuously in the electrolysis process with average cell voltage of 3.422 V,but the content Cu impurity in primary aluminum reached 4.5%.The cell voltage also varied inconspicuously with average cell voltage of 3.829 V for 10Cu50Ni40Fe alloy anode in the electrolysis process,and the purity of primary aluminum could achieve up to 99.74%,indicated that the 10Cu50Ni40Fe alloy anode possessed the optimal electrolysis performance among the three kinds of alloy mentioned above.The changes in the composition,structure and morphology of the alloy anode surface after electrolysis were characterized by the techniques of XRD,SEM and EDS etc.The results exhibited that the oxide membrane compositions on the three kinds of alloy anode surface differed from each other distinctly,and NiO and Ni0.8Cu0.2O with loose structure formed on the surface of 60Ni40Fe and 65Cu25Ni10Fe alloy anodes,respectively.The element scan of the oxide membrane on10Cu50Ni40Fe alloy anode surface showed a layered distribution of all the elements,and compact Ni1.25Fe1.85O4 that possessed protective effect on alloy anode formed on the alloy surface,which could suppress the corrosion of alloy matrix.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2011年第1期72-77,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金资助项目(51004017
51004016)
国家"863"计划资助项目(2008AA030503-3)
博士后基金资助项目(20080440335)
关键词
NiFe合金
铝电解
惰性阳极
钾冰晶石
腐蚀
NiFe alloy
aluminum electrolysis
inert anode
potassium cryolite
corrosion
