Dynamic Modelling of Alumina Feeding in an Aluminium Electrolysis Cell

Alumina feeding at regular intervals requires optimization for the feeder positions, their number, the feed amount and the timing. The specific composition of the feed material could be variable in the particulate material sizes and the specific density. The addition of particles of various sizes is treated by Lagrangian methods following the tracks of inertial particles subject to drag in the turbulent electrolyte flow. The emphasis is on the large scale circulation which is essential to achieve the desired uniform alumina composition over the whole cell. Each particle is permitted to gradually dissolve in dependence of its individual size and the local concentration field value below the saturation level. This time variable source is used to follow the concentration field development on the Eulerian grid. The newly developed modelling technique is implemented as an add-into the specialised MHD software for commercial cell modelling and optimisation.