2022 Light Metals Keynote Session: LIVESTREAMED SESSION: 50 Years of Continuous Light Metals Proceedings - Highlights and Vision for the Century
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Linus Perander, Yara International
Monday 8:30 AM
February 28, 2022
Room: 204B
Location: Anaheim Convention Center
Session Chair: Linus Perander, Yara International
8:30 AM Introductory Comments: Linus Perander, Yara International
8:35 AM Keynote
An Overview of the Last 50 Years of the Bayer Process: Gyorgy Banvolgyi1; 1Bán-Völgy Limited Partnership
Over the last 50 years the World’ alumina production have increased dramatically (from 21 Mt in 1970 to 133 Mt in 2020). The primary energy consumption of the alumina production has decreased significantly. The bauxite and NaOH consumptions are determined by the quality of the bauxite feedstock, the process technology and equipment has relatively minor impact. Nowadays about 95% of the World’ alumina production is based on the Bayer process, in exceptional cases the combined Bayer-sintering processes. It is deemed therefore to be reasonable that this overview focuses on the Bayer process. The development of the Bayer process will be discussed primarily on the Light Metals proceedings of the last 50 years. It is anticipated that the papers will be classified as it follows: *An introduction on what bauxite, Bayer process and bauxite residue are; *Chemistry of the Bayer process; *Development of the Bayer process technology (by principal unit operations); *Reduction of the energy consumption; *Process control; *Equipment and capacity development of the production lines; *Quality control; *Bauxite residue (red mud) as principal by-product. As closing remarks the tendencies from the assessment of the development of the past fifty years and a likely roadmap for the foreseeable future will be outlined.
8:55 AM Keynote
The Evolution of Smelting Aluminas: James Metson1; 1University of Auckland
The aluminium smelting industry is fortunate in utilising a dominant raw material alumina that performs a range of functions in the process and has proved remarkably flexible in responding to an evolving industry. However the biggest challenge the industry faces is now upon us in the greening of the process in an increasingly carbon constrained world. This presentation will deal particularly with the calcination of alumina, both what we will need of alumina and the prospect of what we can do about the energy footprint of the process. The announcement in June 2021 of Rio Tinto’s study into using hydrogen in alumina refining is but one example of some of the thinking in this direction, following on from an Alcoa initiative in electrically sourced refinery steam. In the calcination process the challenge is also to best understand the alumina product we are likely to require as other innovations are embedded in the smelting process.
9:15 AM Keynote
Review of Different Types of Models Related to Aluminum Reduction Cell Design and Operation: Marc Dupuis1; 1GeniSim Inc.
Hall-Héroult cells are multiphysics in nature and very challenging to model. The aluminium industry has invested huge resources in the development of mathematical models to support its cell design and operation. First, here is the cell thermo-electric model that, once validated, can correctly predict the cell heat balance and ledge profile. Second, the very complex magneto-hydrodynamic (MHD) cell model, that once validated, can correctly predict the cell stability threshold. Today, it would be unthinkable to design efficient high amperage cells without the help of those two types of models. A third type of model is the bath bubble flow model used to support the effort to minimize the bubble layer impact on the bath electrical resistance below the anodes. This type of model is now a subset of a new emerging type of model currently under intensive R&D development: the alumina dissolution model.Of course, many more types of models have been developed to support cell and potroom design, including potshell, busbar and anode beam mechanical models, potroom ventilation CFD model, etc. Finally, the dynamic cell simulation model should become very important in the years to come to act as the kernel of “digital twins” in emerging digital twin-based cell control logic.
9:35 AM Keynote
50 Years of Fundamental Research, Continuous Development, and Technology Innovation within the Aluminum Smelting Industry: Jayson Tessier1; 1Alcoa Corporation
The World has changed significantly over the last 50 years, and so did the aluminum industry. From the state-of-the-art smelters using Sřderberg or small pre-baked cell technologies operating in the 100kA’s, engineers and scientists have pushed the smelting technology up to 600kA, suing side-by-side potroom configuration and point-feeding. Strong from fundamental research, advances in process control and cell materials, improved work practices and automation, aluminum producers have partnered with universities, engineering firms and equipment suppliers to increase productivity while reducing energy consumption and environmental footprint. This presentation will review some of the main development that happened over the last 50 years.
9:55 AM Break
10:10 AM Keynote
50 Years of Aluminum Cast House Technology Development: Lessons from 5 Case Studies: John Grandfield1; 1Grandfield Technology
There are many processes used in cast shops to produce cast product and there have been reviews of the development of these processes. A full review of cast shop technology can not be tackled here but the technology progression in five key areas; inclusion removal, inclusion detection, extrusion billet and rolling slab direct chill casting and degassing technology is explored to develop key themes. These are * there are always problems to solve and new solutions just around the corner * old ideas can be made good and existing methods made obsolete * Persistence pays off * New materials, sensors, modelling and automation are significant enablers of new technologyAs in the past, future developments will be driven by cost & quality but more than ever by safety and environment and most importantly by climate change. Cast shop furnaces can be switched to green or turquoise hydrogen or renewables and electric furnaces. The path to zero carbon scope 1 and 2 in cast shops is apparent but reducing Scope 3 emissions such as those associated with alloying additions in particular magnesium is less clear. Completely hands free casting is well established but not yet universally adopted. Automated furnace skimming has been developed and is expected to become the norm. The elimination of tapped bath and dross is expected within 15 years.
10:30 AM Keynote
From Grain Refining to Casting Defects: Simplicity in Complexity: Dmitry Eskin1; 1Brunel University London
The link between grain refinement and casting defects such as hot tearing, cold cracking and macrosegregation is recognised for decades. Actually, the grain refining practice serves primarily this purpose – to produce high quality defect-less billets/ingots. The mechanisms behind this connection are, however, rather complex and multi-dimensional. Without recognising these mechanisms and their complexity and interrelation, the occurrence of defects under particular conditions remains a mystery that is almost impossible to decipher. Different mechanisms may act in different proportions and drive the system in different directions, depending on the particular casting conditions. So oversimplification of the analysis leads necessarily to the complexity. On the other hand, knowing these complex mechanisms makes the analysis of the casting defects and the ways for their prevention a rather transparent and simple task. In this presentation, the interrelation between the grain refinement and the casting defects will be explained and illustrated with the data published in TMS Light Metals proceedings over the last 50 years.
10:50 AM Keynote
Challenges for the Carbon Transition – Revisiting 50 Years of Anode Technology Development: Alan Tomsett1; 1Rio Tinto Pacific Operations
Anode technology has always been a major part of the Light Metals symposia at the TMS Annual Meeting. While there have been many groundbreaking papers over the last fifty years, the biggest challenge today is how to support the transition to low carbon technology. The International Aluminium Institute (IAI) has estimated that the total emissions from the smelting process was greater than 850 Mt CO2e in 2018. The Light Metals anode papers from the last 50 years have been revisited to identify those that may help with the transition to lower carbon emissions. Major opportunities to be explored are alternative raw materials and inert anodes, reducing carbon consumption in the electrolysis cells, reducing voltage drop through the anode assembly and reducing process CO2 from anode production.
11:10 AM Keynote
50 Years of Research and Developments on Cathode Designs in Aluminium Reduction: Arne Ratvik1; 1SINTEF
Electrolytic production of aluminium has changed tremendously over the last 50 years, and this is no exception to cathode materials and designs. Over this period the lifetime of cathodes has doubled from an average lifetime of around 1000 days; this being a testimony for the many scientific developments since then. The presentation will cover some of the major developments in cathodes over the decades and the implications these have had on modern aluminium production. Major changes in cell arrangement and cell dimensions as well as composition of carbon cathode and refractory materials are only some of the many developments that have been implemented. Also, the compensation of the magnetohydrodynamic forces created by the amperage increase from large cells around 150-200 kA 50 years ago to modern cells reaching 600 kA have been important for maintaining long lasting cathodes.
11:30 AM Panel Discussion