Formation of Al-Ni master alloys using nickel anode
(1.School of Materials Science and Engineering, Shenyang Institute of Chemical Technology, Shenyang 110141, China;
2. Science and Technology Department, Yunnan Metallurgy Group, Kunming 650016, China;
3. School of Materials and Metallurgy, Northeastern University, Shenyang 110006, China)
2. Science and Technology Department, Yunnan Metallurgy Group, Kunming 650016, China;
3. School of Materials and Metallurgy, Northeastern University, Shenyang 110006, China)
Abstract: Nickel anode was investigated as a potential anode of aluminium electrowinning for preparation of Al-Ni master alloys. The electrolysis tests were carried out in Na3AlF6-Al2O3 based melts at 940 ℃. The results show that the cell voltage during electrolysis has only minor instability, and there exists NiO phase in electrolyte after 0.5 h electrolysis. Ni content in Al-Ni master alloys increases with increasing the electrolysis time. Concentration limit of Ni in Al-Ni master alloys can be up to 33.8% (mass fraction). However, substantial corrosion of the Ni-metal substrate is observed, and the oxide scale on the nickel anode after electrolysis is porous and loose that does not prevent corrosion of the substrate.
Key words: inert anode; Ni-metal anode; Al-Ni alloy; electrolysis; corrosion