Aluminum production

Aluminum is almost never present in his pure form in the nature. In order to obtain it, it must be extracted from a more complex molecule, such as alumina ( Al2O3 ).The extraction process consist to inject solid alumina in an electrolysis cell containing a highly corrosive solution and liquid aluminum. A strong electric current go through the cell and the liquids are keep at a temperature close to 960o Celsius, according to Joule effect. The two fluids are immiscible and moving due to electromagnetic forces.

The main chemical reactions that allow to extract aluminum from alumina can be summarized by the following equation :

 2 Al2O3 + 3 C = 4 Al + 3 CO2.

In a very simplified way, due to the presence of the solvent liquid, the alumina molecules are ionized and transported by the electrical current. The oxygen part react with the carbonic anodes and produce carbon dioxide and thus allow the formation of pure aluminum.

 

As part of a strong scientific collaboration between the EPFL and RioTinto-Alcan (Laboratoire de Recherche et Fabrication based in Saint-Jean de Maurienne – France), the chair ASN developped for many years an aluminum production simulation software (Alucell).

As an example, here is the geometry of a realistic cell, used for industrial simulations.

 

Recent Publications

N. Jimenez-Mena; P. J. Jacques; J. M. Drezet; A. Simar : On the Prediction of Hot Tearing in Al-to-Steel Welding by Friction Melt Bonding; Metallurgical and Materials Transactions. 2018-04-13. DOI : 10.1007/s11661-018-4618-z.
S. Flotron; J. Rappaz : Conservation Schemes For Convection-Diffusion Equations With Robin Boundary Conditions; Esaim-Mathematical Modelling And Numerical Analysis-Modelisation Mathematique Et Analyse Numerique. 2013. DOI : 10.1051/m2an/2013087.
S. Flotron / J. Rappaz; M. Picasso (Dir.) : Simulations numériques de phénomènes MHD-thermiques avec interface libre dans l'électrolyse de l'aluminium. Lausanne, EPFL, 2013. DOI : 10.5075/epfl-thesis-5738.
J. Descloux; M. Flueck; J. Rappaz : Modelling and mathematical results arising from ferromagnetic problems; Science China-Mathematics. 2012. DOI : 10.1007/s11425-011-4306-6.
T. Hofer / J. Rappaz (Dir.) : Numerical Simulation and Optimization of the Alumina Distribution in an Aluminium Electrolysis Pot. Lausanne, EPFL, 2011. DOI : 10.5075/epfl-thesis-5023.
M. Flueck; T. Hofer; M. Picasso; J. Rappaz; G. Steiner : Scientific Computing For Aluminum Production; International Journal Of Numerical Analysis And Modeling. 2009.
G. Steiner / J. Rappaz (Dir.) : Simulation numérique de phénomènes MHD. Lausanne, EPFL, 2009. DOI : 10.5075/epfl-thesis-4469.
C. D'Angelo / A. Quarteroni (Dir.) : Multiscale modelling of metabolism and transport phenomena in living tissues. Lausanne, EPFL, 2007. DOI : 10.5075/epfl-thesis-3803.
S. Pain / J. Rappaz (Dir.) : Simulation numérique du mouvement des fluides dans une cellule de Hall-Héroult. Lausanne, EPFL, 2006. DOI : 10.5075/epfl-thesis-3497.
G. Rozza / A. Quarteroni (Dir.) : Shape design by optimal flow control and reduced basis techniques. Lausanne, EPFL, 2005. DOI : 10.5075/epfl-thesis-3400.
M. Morozov / N. Setter (Dir.) : Softening and hardening transitions in ferroelectric Pb(Zr,Ti)O3 ceramics. Lausanne, EPFL, 2005. DOI : 10.5075/epfl-thesis-3368.
I. Stevanovic / J. R. Mosig (Dir.) : Modeling challenges in computational electromagnetics. Lausanne, EPFL, 2005. DOI : 10.5075/epfl-thesis-3212.
N. Parolini / A. Quarteroni (Dir.) : Computational fluid dynamics for naval engineering problems. Lausanne, EPFL, 2004. DOI : 10.5075/epfl-thesis-3138.
M. Discacciati / A. Quarteroni (Dir.) : Domain decomposition methods for the coupling of surface and groundwater flows. Lausanne, EPFL, 2004. DOI : 10.5075/epfl-thesis-3117.
M. Sahin / R. Owens (Dir.) : A numerical investigation using a novel finite volume method of some flow instabilities. Lausanne, EPFL, 2004. DOI : 10.5075/epfl-thesis-2971.
S. Deparis / A. Quarteroni (Dir.) : Numerical analysis of axisymmetric flows and methods for fluid-structure interaction arising in blood flow simulation. Lausanne, EPFL, 2004. DOI : 10.5075/epfl-thesis-2965.
S. Rousseau / J. Lemaître (Dir.) : Vieillissement des biociments brushitiques. Lausanne, EPFL, 2004. DOI : 10.5075/epfl-thesis-2916.
M. Mattes / J. R. Mosig (Dir.) : Contribution to the electromagnetic modelling and simulation of waveguide networks using integral equations and adaptive sampling. Lausanne, EPFL, 2003. DOI : 10.5075/epfl-thesis-2693.