The Hall-Héroult aluminium reduction is an energy-intensive process with Specific Energy Consumption (SEC) ranged in 12-15 kWh/kg Al, with around 50% of energy efficiency. Thus, reducing energy consumption through investment in advanced technologies and practices can enhance manufacturing competitiveness and collaborate to reduce the aluminium industry carbon footprint.

Along the years, Aluar implemented a continuous research and development program that led to several upgrades of the original cell designs. Since 2018, the introduction of copper inserts in collector bars to reduce cathode resistance in Lines C and D, the consequent redesign of the lining to maintain thermal balance, and the installation of shell cooling fins have resulted in the reduction of 0.5 kWh/kg Al. This paper highlights the improvement process and the road map to convert 384 cells to a more energy efficient design, which is currently under way.

At Aluminium Bahrain (ALBA), the world's largest single-site aluminium smelter outside of China, in reduction lines 4 & 5, line amperage successfully increased from 400 kA to 411 kA in a short record period after Forced Cooling Network (FCN) installation. During our amperage increase journey we have used two different lining designs with copper insert. Alba is planning to increase amperage further to 415-420 kA during the next 2-3 years. In line with this amperage increase plan, two more lining designs were added. We are currently operating at 412 kA, and all the four lining designs are in operation. The behavior and challenges of different lining designs with amperage increases after FCN installation along with the future preparation are discussed in this paper.

In April 2007, Alcoa Fjarðaál smelter started its first cell using the Aluminium Pechiney technology AP30 platform, fitted with an Alcoa cell lining design intended for an initial nominal amperage above 300 kA. The AP30 technology was also used at Alcoa Deschambault smelter since 1992, which was at the time the state-of-the-art cell technology. Based on already proven technology solution, supplemented with our fundamental knowledge and experience, Alcoa decided to use the same platform for its Fjarðaál smelter. Since then, the Fjarðaál smelter has tested and deployed different cell designs that have demonstrated excellent performance. The third reline wave has been ongoing since March 2020. Aiming to increase the amperage above 380 kA, Alcoa Fjarðaál initiated a large-scale trial of new cell designs. In addition to already available developments, two new conceptual cell designs were developed targeting specific characteristics of the smelter. Performance tests were carried out on a group of 10 cells using a given design and 20 cells with a different design. Operational performance metrics were statistically compared to the selected reference standard design. This paper presents a description of Alcoa’s cell design change governance and a comparison between the different designs.