Electrode Technology for Aluminum Production: Carbon Anode Development and Production - Where is the Cutting Edge?
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Duygu Kocaefe, University of Quebec at Chicoutimi
Monday 2:30 PM
February 24, 2020
Room: 3
Location: San Diego Convention Ctr
Session Chair: Barry Sadler, Net Carbon Consulting Pty Ltd
2:30 PM Introductory Comments
2:35 PM Keynote
The Development of Anode Shape, Size and Assembly Designs - Past Present and Future Needs: Barry Welch1; 1Welbank Consulting
With the shortage of green energy supply, the growing demand for aluminium and needs to lower the Carbon footprint smelters are shifting to high productivity, minimum energy cell operation as well as targeting minimum net carbon. The anode shape, size, and setting pattern in the cells all have an impact on both the energy efficiency and the net carbon. Slots have been introduced to lower the resistance of the electrolyte. While slots therefore enabled increasing cell line current, there has been a consequential reduction the anode cathode distance and the electrolyte volume. Slots have reduced the driving force for electrolyte flow and mixing. Increasing anode mass has resulted in extended times for the anode to preheat and draw full current. Thus the changes have introduced greater spatial variation in cell conditions. This paper open discussion in the hope of determining the perfect anode design for smelters beyond the year 2020.
3:05 PM Keynote
10 Years of Anode Research and Development: Alcoa & Université Laval Experience: Jayson Tessier1; Julien Lauzon-Gauthier1; Mario Fafard2; Houshang Alamdari2; Carl Duchesne2; Louis Gosselin2; 1Alcoa; 2REGAL
In 2009, Alcoa started an extensive research and development program with different professors from Université Laval in Quebec City. The program, mainly oriented into advanced modeling, carbon material and advanced statistics, was aimed at improving our R&D capability by enhancing our core technical expertise. Universities offer a diverse in-depth fundamental expertise that is not necessarily available in-house, where industrial researchers are oftentimes more oriented into applied research. Universities also provide hi-tech specialized laboratory equipment not available within typical industry laboratory. After 10 years, about 60 graduate students have obtained a master's or PhD degree. This presentation summarizes different results obtained throughout this fruitful journey as well as key learning on developing and maintaining relationship between University and Industry partner.
3:30 PM Invited
Carbon Anode Raw Materials – Where is the Cutting Edge?: Les Edwards1; 1Rain Carbon Inc.
The CPC and CTP raw materials used for anode production are both manufactured from byproducts of other industries which makes the aluminum industry dependent on others for two key raw materials. Despite this, the industry has made steady improvements in anode quality and performance over the last 50 years. Production processes for CPC and CTP have gotten more sophisticated but changes in feedstock availability for these raw two materials are starting to be felt by the industry. Average CPC quality has changed quite significantly over the last 10 years but the industry has adapted well and this is expected to continue in the future. By contrast, CTP quality has been quite stable over the last 10 years but the impact of declining coal tar production is starting to be felt by the industry. The paper will review current and future challenges for anode producers and where the cutting edge for anode raw materials lies today.
3:55 PM Break
4:10 PM Invited
Solids Flow Considerations and their Impact in Smelter Carbon Plant Operations and Product Quality: Brian Pittenger1; Andrés Orlando1; 1Jenike & Johanson, Inc.
Segregation and material flow are common problems in smelter carbon plants. These problems significantly impact operations and quality. An understanding of the (practical) science of material flow, especially in/out of silos, bins, and hoppers will be described, along with critical flow properties. Specific examples of flow problems will be covered, along with approach(es) to ensure proper design and retrofit processes to eliminate various flow problems.
4:35 PM Invited
How to Improve the Environmental Efficiency of the Hall-Heroult Process While Producing and Using Carbon Anodes?: Antti Koulumies1; Ana Maria Becerra1; Lasse Piechowiak1; Paul Merlin2; Martin Zapke1; 1Outotec GMBH & CO KG; 2Outotec Canada Ltd
Carbon anodes will likely stay as the primary reduction medium in aluminium smelting for years to come, despite the ongoing development of inert anodes. This is due to the excess production of carbon coke as a by-product of hydrocarbon distillates and the CO2 profile of energy production, making inert anode likely best suited for regions with Hydropower as opposed to e.g. coal power.This means that industry must increase the environmental performance of the Hall-Heroult process. We list several levers by which this can be done from an anode producers perspective. Levers include direct, examining factors to increase efficiency of anode production; indirect, examining factors that increase potline efficiency and fuel, examining potential to use renewable materials in anode production. We conclude that the Hall-Heroult process still has a lot of potential to reduce its carbon footprint. The paper is a combination of literary review, and several industry examples.
5:00 PM Invited
Trends in Carbon Anode Production: Derek Santangelo1; 1Hatch
In response to market conditions, there has been a reduction in concurrent major projects. As a result, this has led to a perceived slowdown in innovation within the anode sector. To explain why, we will review trends and demonstrate how they have contributed to this change. Innovation and technological developments were means to both improve the industry and ensure that key players maintained a competitive advantage in an aggressive market. Without an abundance of projects to fuel innovation, a shift was bound to occur. With a focus on capital reductions, industry players have shifted their efforts, and this has led to change in project execution, rather than technology. Finally, a review of technical step changes shows that they are not favored in comparison with incremental improvements. This, when compounded with a conservative sector, demonstrates that when presented with innovation, the appetite for risk remains low.
5:25 PM Panel Discussion