Aluminum Reduction Technology: Alumina Dissolution and Dispersion
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Kristian Etienne Einarsrud, Norwegian University of Science and Technology; Stephan Broek, Kensington Technology Inc; Mertol Gokelma, Izmir Institute of Technology; Dmitry Eskin, Brunel University

Tuesday 2:30 PM
March 1, 2022
Room: 209B
Location: Anaheim Convention Center

Session Chair: Andrey Yasinsky, Siberian Federal Institute


2:30 PM Introductory Comments

2:35 PM  
Advanced Alumina Dissolution Modelling: Valdis Bojarevics1; Marc Dupuis2; 1University of Greenwich; 2GeniSim Inc
    Alumina feeding requires optimization for the feed amount, timing, and point feeder locations. The alumina raft formation and dispersion are the essential features leading to particles of various sizes to travel with the bath flow along anodes in the central channel, in the bath volume beneath the anodes, and gradually dissolving. The raft motion and particles are traced accounting for their inertia, drag in the turbulent flow, and the anode bottom surface shape. The large-scale MHD-driven circulation in the cell is modelled using specific inputs corresponding to real commercial cells of various types. The time-dependent feed material rafts and particles gradually dissolve in the dependence of the local turbulent diffusion and the instantaneous concentration level below saturation in the location. The newly developed modelling technique is applied to illustrate possible optimization of the feeder locations, the variable feeding time intervals and possible adjustments in the long-term process.

3:00 PM  
Oxide Sensor Measurements and Simultaneous Optical Observations during Dissolution of Alumina in Cryolite Melt: Luis Bracamonte1; Kristian Etienne Einarsrud1; Christian Rosenkilde2; Espen Sandnes1; 1Norwegian University of Science and Technology; 2Hydro Aluminium
    Faster dissolution of alumina in a cryolite based bath is one of the key challenges for increasing the energy efficiency and production rate for the Hall-Héroult process. More knowledge of the alumina dissolution process becomes important in order to obtain the improvements. In this work an alumina sensor based on the electromotive force principle was applied to measure the concentration of dissolved alumina in a cryolite based bath from the addition of the alumina and throughout the entire dissolution process. Simultaneously, the dissolution process was video recorded. The measurements were performed in a see-through furnace applying a crucible of quartz, and three different industrial grade secondary aluminas were added in 1 wt% subsequent additions. The general working principle of the sensor was studied and the information extracted from the video recordings was used to explain the sensor results as well as the general dissolution phenomena at different alumina concentrations.

3:25 PM  
Bauxite & Alumina: Now and In the Future: Lavinya Kugaswaran1; 1International Aluminium Institute
    Introducing the International Aluminium Institute and the activities of the Bauxite & Alumina Committee. This presentation outlines the current situation of aluminium today and addresses the future outlook on topics related to bauxite mining and alumina refining.