Adapting Modern Industrial Operation Parameters in a Standardized Laboratory Cell for Measuring Current Efficiency for Aluminium Deposition: Unexpected Challenges and Lessons Learned

Abstract

“Current efficiency” is an important cell parameter which shows how efficiently current is used to produce aluminium. Operational parameters that affect current efficiency have been widely studied in the aluminium industry, and factors like electrolyte composition and superheat have been changed to improve the current efficiency. However, the industrial cell is a complex system where all parameters are closely interrelated, which makes it difficult to change any parameter independently. Sterten and Solli developed a laboratory cell specifically designed to study current efficiency. Many studies have been made using the cell to study the effect of various operational parameters on current efficiency. As a result of improved understanding, the operational parameters presently used by the industry have changed, which is reflected by new operating condition standards for the laboratory cell. This study focuses on the challenges faced when implementing new standards in the current efficiency laboratory cell; these standards (11.5% AlF3, 5% CaF2, 4% Al2O3, cryolite ratio 2.2, temperature 965 °C) are comparable to typical parameters in the aluminium industry today.