EXERGETIC ANALYSIS OF THE ENEXAL BAUXITE RESIDUE TREATMENT ON THE OVERALL RESOURCE EFFICIENCY OF THE PRIMARY ALUMINA REFINING PROCESS

In the framework of the ENEXAL FP7 project, a novel process for treating bauxite residues has been developed and demonstrated in industrial scale. The novel process developed, fully converts the bauxite residues in to marketable products such as pig iron and mineral wool fibers. In this work a detailed exergy analysis of the new process is presented and coupled with the flow-sheet of the primary alumina refining process (Bayer), in order to deduce its effect on the overall resource efficiency and exergy utilization. A methodology for evaluating the chemical exergy of mineral phases and solid solutions is also discussed.