Waste Prevention Through the Use of Monolithic Refractory Lining in Aluminum Reduction Cells: A Mineralogical Case Study

One of the most costly factors in the production of aluminum is the consumption of energy in the form of electricity. Energy consumption is increased as refractories in the Hall-Heroult reduction cells are corroded by penetration of the fluxes cryolite (Na3AlF6) and villiaumite (NaF). To decrease thermal conductivity and refractory waste, protective barrier linings are installed. This research project characterizes four dry powder compositions composed of vermiculite, corundum, wollastonite, and anorthite mineralogically using methods such as X-ray diffraction, reflected light microscopy, scanning electron microscopy, and cathodoluminescence microscopy. The study aims to evaluate the effectiveness of dry powder barrier linings in reducing refractory waste and improving energy efficiency in aluminum reduction cells. Preliminary results demonstrate that the conversion of the corrosive fluxes to insoluble products forms a crystalline barrier that can significantly reduce the refractory wear, thus offering insights into the long-term application of anorthite-based dry powders in operating aluminum reduction cells. This study contributes to the development of more sustainable practices in aluminum production through the optimization of refractory materials.