Sodium content in aluminum and current efficiency — correlation through multivariate analysis

Abstract

Current efficiency is an important indicator used in the aluminum reduction technology. Values for this indicator are usually determined among potlines and they are not representative of the fluctuations that may occur in a single electrolysis cell. To measure or calculate an accurate value on a monthly basis would be a very interesting tool for process technicians and engineers to help regulate and analyse the performance of the pot. The potential use of the sodium content of aluminum as an indicator of current efficiency is investigated. Many authors discussed its role and indicated a possible correlation with the current efficiency. Aluminerie Alouette Inc. performed some univariate statistical analysis to confirm this correlation on a potline scale. Furthermore, multivariate analysis is performed to strengthen the correlation according to other indicators. Results from these analyses and the possible implementation as an indicator is discussed in this paper.