Aluminum fluorideAluminum fluoride is a valuable commodity chemical, critical to maintaining process stability during aluminum electrolysisAluminum electrolysis. The current commercial process for producing aluminum fluorideAluminum fluoride is entirely dependent on fluorspar as a fluorideFluoride source. Alcoa has previously reported the successful laboratory scale use of surplus pure bathPure bath as a feedstock for producing aluminum fluorideAluminum fluoride. This is accomplished through a solid-state reactionSolid-state reaction between pure bathPure bath and aluminumAluminum sulfate. The reaction converts the fluorideFluoride present in the pure bathPure bath to aluminum fluorideAluminum fluoride and the variousValorization cations to their respective sulfates, such as sodium and calcium sulfate. In pursuit of further development of this process, a pilot scale trial was undertaken. This provided an opportunity to run the process for an extended period of time, confirm the performance of the process at a larger scale, and collect data for later use in engineering studies.