Aluminium fluoride consumption and control in smelting cells

For optimum operation and performance of aluminium smelting cells, each technology has an ideal aluminium fluoride concentration for the solvent electrolyte. The actual value used is influenced by the alumina dissolution and varies because of different alumina‐feeding technologies. The aluminium fluoride is consumed within the cell and therefore, chemical analysis is performed as part of the process to determine the amount required for replenishment of the consumption. However the cell has a dynamic energy balance and that causes simultaneous variations in the distribution of solid and liquid electrolyte components, complicating the overall situation. Ultimately, it results in the chemical analysis varying. Thus, it becomes a major challenge to determine the amount of aluminium fluoride that needs to be added to replenish the consumption, whilst maintaining the cell at close to its optimum range.