Aluminum Reduction Technology: Pot Design & Start-Up
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Pierre Marcellin, Rio Tinto; Stephan Broek, Kensington Technology Inc
Thursday 2:00 PM
March 23, 2023
Room: 30E
Location: SDCC
Session Chair: Abdalla Zarouni, Emirates Global Aluminium
2:00 PM Introductory Comments
2:10 PM
Achieving Low Pot Failure Rate at Aditya Aluminium: Atanu Maity1; Venkannababu Thalagani2; Bhanu Shankar1; Deepak Dash1; Anish Das1; Kamta Gupta1; Shanmukh Rajgire2; Amit Gupta2; Madhusmita Sahoo1; 1Hindalco Industries Ltd.; 2Aditya Birla Science and Technology, Mumbai
At Aditya Aluminium, the average pot life is about 2000 days, pot relining contributes approximately 2.1 % of total production cost. To avoid risk of pot failure, average 55-60 pots relining/year are planned out of 360 pots. Further, to reduce failure, an in-house pot life estimation method was developed, which helped in planned pot stoppage. Firstly, pots were prioritized based on the pot age, iron & silica, side shell temperature (SST), Current Efficiency and specific energy consumption. These factors were assigned with individual weightage, which helped in pots shut down, further pot autopsy was performed for validation. A strategy was adopted for measuring regular SST, observing iron/silica pick-up and Fe/ Mn ratio. Moreover, forced cooling regulation, and selective collector bar cutting were adopted to extend pot life. These methods helped Aditya Aluminium to establish global benchmark among other AP smelters by achieving pot failure rate ~0.6% since inception.
2:35 PM
Dissimilar Results in Restarting Two Different Potlines: Maria Daviou1; Maria Alejandra Mollecker Rausch1; Ricardo Alonso1; Maria Fernanda Jaitman1; 1Aluar Aluminio Argentino Saic
In March 2020, Aluar reduced its production. Two potlines with different technologies were halted within two weeks’ time. Metal was left in the pots in order to preserve the cathode conditions during stoppage, so the repair procedure for the restart consisted in cleaning the metal surface, sidewall repairing and gas preheating. The restartup of AP22 pots in Potline C was successfully accomplished six months later, with no incidents and a low early failure rate. Two years after, a pre-existed failure mode was identified during the restart of end-to-end al20 pots in Potline B. As a result, a higher amount of pots could not survive.This paper highlights the experience gained of a planned but necessary shutdown of 344 pots together with the challenges involved, not only in restarting two different potlines in a completely diverse context, but also in the strategic criterion proposed for a pot restart in each case.
3:00 PM
Restart of Albras’ Potline 2 – Improving Performance and Changing Paradigms: Bruno Vasconcelos1; Ana Renata Monteiro1; Ana Carolina Guedes1; Michel Pena1; João Vilckas1; Johnson Machado1; Flávio Silva1; Márcio Souza1; 1Albras
In February 2022, Albras lost Potline 2 due to a power outage, shutting down 223 pots. After three months, with the support of Hydro’s technical team, 75% of the pots are in operation and production levels are on the rise. The early failure rate is below 5%. Only 6 tap outs (4 in bath phase) and 2 cut outs due to iron contamination. Daily average number of pots above 1000°C is 5.5. Average acidity has been below 4% in the first 5 days. Originally expected to end in early November, the work is now forecast to finish four months in advance, in July, and there have been no safety incidents. The aim of this work is to describe in detail the pathway leading to what has become the most successful restart in the history of Albras in terms of pace, success rate, process consistency, operational stability, and human capital development.
3:25 PM
Application of Cell Retrofit in GP320 Aluminum Reduction Cell Line: Zhuojun Xie1; Jian Lu1; Weibo Li2; Song He1; Xingyu Yang1; 1Guiyang Aluminum & Magnesium Design & Research Institute Co. Ltd.; 2Guangyuan Zhongfu High Precision Aluminum Co., Ltd.
Retrofitting older aluminum reduction cell line is an effective way to extend the productive life of an aluminum smelter. With the modification of busbar system, cathode lining design and superstructure design, the GP320 aluminum reduction cell can achieve the target of both current creep and energy saving. In July 2020, a retrofitted GP320 cell line was started up (which was initially designed in 2002 and started up in 2003), and the current has been increased to 340kA. Until June 2022, all the cells are operating at stable, high-efficient condition. The retrofit has reached the design target and shown a great example for the future of older cell lines.
3:50 PM Break
4:05 PM
The Expanded Industrial Pilot of SAMI’s NCCT+ Technology: Xi Cao1; Yafeng Liu1; Hongwu Hu1; Xuan Wang1; Jinlong Hou1; Wei Liu1; Kangjian Sun1; Michael Ren2; 1Shenyang Aluminum and Magnesium Engineering and Research Institute Co. Ltd.; 2Sunlightmetal Consulting Inc.
Shenyang Aluminum and Magnesium Engineering and Research Institute Co. Ltd (SAMI) has carried out a series of technical research and experiments since 2015 to develop a more environment-friendly and energy-efficient aluminum reduction technology. By adopting the technical route of improving MHD stability while reducing cathode voltage drop, SAMI's New Conceptual Cathode Technology namely NCCT Technology has been developed. In 2019, this technology has been applied and verified in Indonesian INALUM aluminum smelter’s upgrade project. Since then, an expanded industrial test was implemented on two SY500 potlines in 2021 and a newer version of NCCT Technology has been developed, called NCCT+ Technology. Statistical data over the past year demonstrates that energy consumption of NCCT Technology is < 12,300 kWh/t Al, while that of the NCCT+ Technology is < 12,200 kWh/t Al. Both these technologies provide strong technical support for aluminum industry to upgrade existing low-amp reduction cells for better carbon emission.
4:30 PM
The SY500 Potline Technology Development: Kangjian Sun1; Yafeng Liu1; Hongwu Hu1; Xuan Wang1; Jinlong Hou1; Wei Liu1; Xi Cao1; Michael Ren2; 1Shenyang Aluminum and Magnesium Engineering and Research Institute Co. Ltd.; 2Sunlightmetal Consulting Inc.
Since 1996, Shenyang Aluminum and Magnesium Engineering and Research Institute Co. Ltd. (SAMI) has developed a series of aluminum reduction technologies for prebaked anodes potlines, the SY series, ranging from 160kA, 190/200kA, 230/240kA 280kA, 300kA, 350kA to 400kA. In 2009, SAMI developed the 500kA reduction technology called SY500, and since then has been continuously improving this technology, and has applied it in the engineering of new aluminum smelters. The paper introduces the development of the first, second and third generation SY500 potline technology, systematically analyzes breakthroughs of new technologies adopted by SY500 potline technology, such as the New Conceptual Cathode Technology (NCCT), New Conceptual Busbar Technology (NCBT), Network Busbar Technology (NBT), etc. The SY series potline technology has been validated for its excellent technical and economic performances and become the most widely used new aluminum reduction technology in the world.
4:55 PM
Preheat, Start-up and Early Operation of DX+ Ultra Pots at 500 kA: Nadia Ahli1; Mustafa Mustafa1; Abdalla Alzarooni1; Konstantin Nikandrov1; 1Emirates Global Aluminium
In Emirates Global Aluminium (EGA), the first pots were started up in 1979 in its Jebel Ali smelter (then called Dubai Aluminium - DUBAL), using Kaiser P69 cells at an amperage of 150 kA. In 2014 EGA started up its flagship, home grown DX+ Ultra technology at 450 kA. In 2017 DX+ Ultra was upgraded targeting operations at higher amperages, eventually reaching 480 kA by 2019. Now, in 2022, EGA succeeded in starting up DX+ Ultra technology at 500 kA. This was done on 5 pots in it’s Jebal Ali smelter research and development demonstration section called Eagle. This paper aims to describe some of the adjustments made from previous generation of DX+ Ultra technology to enable the additional 20 kA amperage increase and start up the pots at 500 kA. It also details some of the related challenges and results from the preheat, start-up and early operations periods