Aluminium production process: from Hall-Heroult to modern smelters

This article gives a brief overview of the history of modern aluminium production, which started with the invention of electrowinning of dissolved aluminium oxide in molten cryolite (Na3AlF6)-based electrolytes in 1886. All primary aluminium production is still based on the same principles, although numerous improvements and adoptions have been developed over the years. A historical development of the process is followed by brief fundamental and thermodynamic aspects of the reactions. Some of the most important developments are described, with a focus on the carbon anode production process. Carbon anodes, which are responsible for the majority of direct greenhouse gas (GHG) emissions by the industry, are discussed thoroughly, and recent developments in inert anodes and utilization of biomass in anode formulation are presented. Finally, the environmental footprint of the process and the trends and objectives of the industry towards improving energy efficiency and mitigating environmental emissions are elaborated.