François Laflamme’s scientific contributions

Anode effects (AE) are considered a nuisance for aluminium production due to the numerous negative impacts that they generate in an electrolysis cell. Previously, great efforts have been deployed to minimize the occurrence of this event. Using online anode current monitoring, Alouette introduced an algorithm to detect abnormalities prior to an AE, allowing sufficient time to apply a corrective action before its occurrence. Several sets of strategies were tested to evaluate the best approach to correct the situation without generating additional problems in the cells. Finally, individual anode currents measurements were connected to the cell control system of two pots to automatically launch preventive treatment of AE. A decrease in the total number of anode effects along with an increased cell stability is noticeable. Other indicators, such as anodic incidents, alumina dosage and metal purity were also compared to make sure that no deterioration in the cell conditions occurred over time.

Since early 2014, Alouette has used a system provided by Wireless Industrial Technologies (WIT) to measure individual anode currents on two pots. The system works by measuring the adjacent magnetic field generated by the current for each anode hanger. This paper summarizes initial difficulties and how they have been overcome. Recent current measurements show good agreement with alternative methods for measuring currents (e.g. mV drop along anode hangers). An algorithm has been developed for discerning an imminent anode effect from changes in the measured magnetic fields due to changes in anode currents. Practical reductions of anode effect frequency, compared to cells of reference, have been achieved by using the results of this algorithm to trigger corrective action through the pot control computer. Some additional potential benefits of anode current measurement are described in the paper.

In aluminium production, the performance of the anode assembly is a great concern which is mainly associated with its energy consumption, aging, fabrication and cleaning process. There fore, a better understandi ng of its in situ behavior is required to efficiently optimize the process using an improved design. In this work, electrical and the rmal data have been me asured on anode assemblies using a specific in situ instrumentation during a complete anode cycle at Aluminerie Alouette Inc. With the help of a numerical model developed on the ANSYS Workbench platform, the evolution of the electrical resistance and current distribution along the anode assembly components has been determined over a complete anode cycle. Considering these information, an innovative prototype has been designed and gave promising results at the laboratory scale. The next step is to confi rm the performance of thi s new design in a real cell.

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.

In aluminium production, the performance of the anode assembly is a great concern which is mainly associated with its energy consumption, aging, fabrication and cleaning process. Therefore, a better understanding of its in situ behavior is required to efficiently optimize the process using an improved design. In this work, electrical and thermal data have been measured on anode assemblies using a specific in situ instrumentation during a complete anode cycle at Aluminerie Alouette Inc. With the help of a numerical model developed on the ANSYS Workbench platform, the evolution of the electrical resistance and current distribution along the anode assembly components has been determined over a complete anode cycle. Considering these information, an innovative prototype has been designed and gave promising results at the laboratory scale. The next step is to confirm the performance of this new design in a real cell.

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.

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.

High performance AP4X cell technologies have been developed as part of a complete cell development program based on AP30 platform. The latest development for this technology is AP4XLE, which refers to low energy consumption cell technology at more than 400 kA with a target for energy consumption at 12.4 kWh/kg. This technology aims at maximizing the production and the profitability of smelters having limited energy block size. It could be used either for retrofit of existing AP30 cells or for green-fields. Following the Rio Tinto Alcan cell development methodology and using modeling and low ACD operation knowledge, lining and anode assemblies were designed to support smelters amperage creeping. Both St-Jean-de-Maurienne and Alouette smelters are involved in the development process by operating tests on designated booster sections. Excellent energetic and environment performances have been recorded from these trials. Prototype cell performances and future technology development steps are described in this paper.

The Alouette aluminium smelter at Sept-Iles, Quebec wascommissioned in 1992 with a nominal capacity of 215,000 tonnesper year based on AP30 cells operating 264 pots at 300 kA. Sincethat time, the plant has expanded considerably, and in 2005 a newpotline of 312 pots was added plus an 18 pots test section. Thecells currently operate slightly over 370 k Amp with plantcapacity now at 600,000 tonnes per year. In the quest for higherproductivity and profitability, Alouette is planning a transition to400 kA based on the use of new, high-amperage, low-energy (LE)AP cells, referred to as AP40LE. In designing this new cell,certain lining, rodding procedures and materials of constructionwere modified. The main performance objectives and thedevelopment steps towards introducing the AP40LE pots andplans for bringing all production lines to 400kA are described inthis paper. © 2012 by The Minerals, Metals, & Materials Society. All rights reserved.

The Alouette aluminium smelter at Sept-Iles, Quebec was commissioned in 1992 with a nominal capacity of 215,000 tonnes per year based on AP30 cells operating 264 pots at 300 kA. Since that time, the plant has expanded considerably, and in 2005 a new potline of 312 pots was added plus an 18 pots test section. The cells currently operate slightly over 370 k Amp with plant capacity now at 600,000 tonnes per year. In the quest for higher productivity and profitability, Alouette is planning a transition to 400 kA based on the use of new, high-amperage, low-energy (LE) AP cells, referred to as AP40LE. In designing this new cell, certain lining, rodding procedures and materials of construction were modified. The main performance objectives and the development steps towards introducing the AP40LE pots and plans for bringing all production lines to 400kA are described in this paper.