Effect of TiN content on properties of NiFe₂O₄‐based ceramic inert anode for aluminum electrolysis

Abstract

There is an intense desire for the substitution of the consumable carbon anode by inert anode (also called non-consumable or oxygen-evolving anode) in the Hall-Héroult process, which would drastically reduce the substantial emission of greenhouse gases such as CO 2 and perfluorocarbons. 1−3 The upgrading of suitable non-carbon anode is highly challenged on account of the numerous restrictive requirements for inert anode materials in the rugged environment of Al electrolytic cell. 2 The basic requirements for an inert anode are as follows: prominent oxidation resistance at high temperature, remarkable corrosion resistance to electrolyte molten salt, high electric conductivity, excellent thermal shock resistance, mechanical robustness, and so on. Up to now, despite major research efforts from Al producers and academic laboratories, no acceptable inert anode material has yet been found for long-term use in industrial Al electrolytic cell.Among the possible inert anode materials (namely, metal, ceramic, and cermet) that have been explored, NiFe 2 O 4based cermet is ranked as the most appropriate candidate, largely owing to the accredited combination of the features of NiFe 2 O 4 ceramics and metals, namely, excellent oxidation resistance at high temperature and high corrosion resistance

Synthesis of Cobalt–Nickel Aluminate Spinels Using the Laser-Induced Thermionic Vacuum Arc Method and Thermal Annealing Processes

“…The resistivity of the annealed sample is around 9.5 to 10 Ω*m, which is lower than that of ceramics, but much higher than that of the metallic thin films, by six orders of magnitude. The electrical conductivity is somewhere around 0.012 S/cm, which is two orders of magnitude below the electrical conductivity of 3.36 S/cm obtained for the NiFe 2 O 4 thin films [ 43 ].…”

Sintering kinetics and properties of NiFe2O4‐based ceramics inert anodes doped with TiN nanoparticles

“…The purchased TiN nanoparticles were of irregular multilateral shape with the average particle size of 22.9 nm. 16 All the chemicals were used as-received without any further purification.…”

“…[14][15][16] The titanium nitride (TiN) nanoparticles have been selected for their special characteristics, such as high melting point (2950 • C), high thermal conductivity and thermal shock resistance, high resistance to corrosion and oxidation, excellent chemical stability, and superior electrical conductivity. [17][18][19][20][21] In our previous research, 16 the TiN nanoparticles have been selected to as a great substitute for metal phase, in order to balance the paradoxical relationship between electrical conductivity and corrosion resistance of NiFe 2 O 4 -based inert anode. Moreover, the effects of TiN nanoparticle contents on the sintering behaviors and the mechanical, electrical, and static corrosion performances of NiFe 2 O 4 -based ceramics have been researched in detail, and the proper content of TiN nanoparticles has been selected as 7 wt%.…”

“…In order to reconcile the contradiction between corrosion resistance and electronic conductivity adjusting by the metallic content, a new method, namely, doping active ceramic phase instead of metal phase, has been proposed. [14][15][16] The titanium nitride (TiN) nanoparticles have been selected for their special characteristics, such as high melting point (2950 • C), high thermal conductivity and thermal shock resistance, high resistance to corrosion and oxidation, excellent chemical stability, and superior electrical conductivity. [17][18][19][20][21] In our previous research, 16 the TiN nanoparticles have been selected to as a great substitute for metal phase, in order to balance the paradoxical relationship between electrical conductivity and corrosion resistance of NiFe 2 O 4 -based inert anode.…”

Greener reactants, renewable energies and environmental impact mitigation strategies in pyrometallurgical processes: A review

“… Material type Anode material Refs. Metallic Cu-based Cu–Al, Cu–Mn, Cu–Fe, Cu–Ni, Cu–Ni–Al, Cu–Ni–Fe 281 – 284 Fe-based Fe–Ni, Fe–Ni–Al, Fe–Co–Ni, Fe–Cu–Ni 285 – 287 Ni-based Ni–Fe, Ni–Fe–Co, Ni–Fe–Cr 288 , 289 Oxide Ceramic Simple Oxide CeO , Cr O , CuO, NiO, SnO , ZnO 290 , 291 Spinel-type CoFe , FeAl , NiAl , NiFe , ZnFe 292 , 293 Cermet Al/Al O/Cu, NiAl /M, NiFe /M, ZnFe /M, WC/Ni-Fe 294 – 297 …”