Study On Cu-Ni-Fe Base Alloy Gas Anode For Aluminum Electrolysis

Inert anode has carried out lots of researches, however, the industrial application of inert anodes have been hindered by high corrosion rate and other issues. This paper studies the CO gas depolarization electrodes, about metal nickel and alloy of Ni-Co-Cu-Fe. as a base used in aluminum electrolytic. Through the anode corrosion behavior observation and analysis of the phase composition after the different alloy composition, current density, the gas flow electrolysis, this paper is expected to obtain suitable alloy gas anode composition and electrolytic processes for aluminum electrolysis.Nickel anode exist static corrosion in CaCl2-10wt%CaO system,and the loose layer of anode increased significantly after electrolytic.Introduction of CO gas can reduce the extent of the electrolytic oxidation of the anode, and such electrolysis have more dense substrate. High cell voltage and a large current density electrolysis anode have lower electrode active.Cobalt doping can improve catalytic effection of CO, reduce cell voltage significantly. High cobalt content in is beneficial to spinel phaseformation and densification within the experimental range. Introduction of CO gas electrolysis is beneficial to the formation and densification of the anodic oxide layer. Co-doped non-proportionally cell voltage is lower during the electrolysis, showing a good electrochemical activity,In the Ni/Co1:3Ni-Co-Cu-Fe anode electrolysis experiment, when the Cu content is too low or high, the electrode surface generate a dense oxide layer, poor compact oxide layer and matrix; When Cu conten22wt%and35wt%, Electrode surface oxide layer compact with the substrate better; When Ni/Co1:3anode, CO5ml/min, the oxide layer and transition layer thickness decreases obviously than CO Oml/min, and the transition layer became more compact; Current density of1-2A/cm2and introduction of CO by electrolysis,58(Ni3Co)22Cu20Fe anode corrosion layer and oxide layer thickness increase with the increasing of current density, density variation, voltage increase and fluctuation. During the Ni/Co3:1Ni-Co-Cu-Fe anode2A/cm2electrolysis experiment, the thickness of the oxide layer decreases with copper content decreasing, and anode surface is easy for forming a dense oxide layer with the copper content decreasing;65wt%Cu alloy gas anode showes better corrosion resistance;65wt%Cu anode, introduction of CO gas is conducive to the anodic oxide layer formed and densification, and the gas flux can reduce the thickness of the oxide layer; With the electrolysis time prolonging oxidation layer becomes thicker and more compact.Under the condition of current density1-2A/cm2, Ni/Co3:1,50wt%Cu gas anode, the oxide layer thickness increases with the increasing of current, but the oxide layer is more dense in a small current density; While under the condition of50wt%Cu, comparison of Ni/Co3:1and1:3gas anode, alloy anode that iron and cobalt nickel consisted of2:1ratios cannot forms oxide layer of protective film well, and it reduces the proportion, enhances the content of nickel and cobaltis that beneficial to the formation of the spinel layer.