Ochsenkuehn-Petropoulou, M.; Tsakanika, L.-A.; Lymperopoulou, T.; Ochsenkuehn, K.-M.; Hatzilyberis, K.; Georgiou, P.; Stergiopoulos, C.; Serifi, O.; Tsopelas, F. Efficiency of Sulfuric Acid on Selective Scandium Leachability from Bauxite Residue. Metals2018, 8, 915.
Ochsenkuehn-Petropoulou, M.; Tsakanika, L.-A.; Lymperopoulou, T.; Ochsenkuehn, K.-M.; Hatzilyberis, K.; Georgiou, P.; Stergiopoulos, C.; Serifi, O.; Tsopelas, F. Efficiency of Sulfuric Acid on Selective Scandium Leachability from Bauxite Residue. Metals 2018, 8, 915.
Ochsenkuehn-Petropoulou, M.; Tsakanika, L.-A.; Lymperopoulou, T.; Ochsenkuehn, K.-M.; Hatzilyberis, K.; Georgiou, P.; Stergiopoulos, C.; Serifi, O.; Tsopelas, F. Efficiency of Sulfuric Acid on Selective Scandium Leachability from Bauxite Residue. Metals2018, 8, 915.
Ochsenkuehn-Petropoulou, M.; Tsakanika, L.-A.; Lymperopoulou, T.; Ochsenkuehn, K.-M.; Hatzilyberis, K.; Georgiou, P.; Stergiopoulos, C.; Serifi, O.; Tsopelas, F. Efficiency of Sulfuric Acid on Selective Scandium Leachability from Bauxite Residue. Metals 2018, 8, 915.
Abstract
Bauxite residue (BR) is a well promising resource for critical metals and especially scandium (Sc), a rare and expensive metal with increasing applications in advanced technology. Particularly, Greek BR’s composition indicates a sound possibility for a commercially viable recovery of Sc under the conditions of an optimized leaching process and the subsequent use of advanced separation techniques. Leaching with mineral acids emerges as the dominant selection with comparison to other techniques. This study investigates an optimized leaching condition set on Sc recovery, using sulfuric acid as the most suitable among different acids tested, in the context of process economics and environmental constraints. Several variables were studied individually or combined in order to achieve high Sc concentration in the leachate as well as to ensure selectivity, especially in respect to iron. The most significant parameters proved to be the solid to liquid ratio (S/L), the final pH value as well as the use of recycling of leachate on fresh BR batches. The proposed process, using sulfuric acid at low acid molarities under ambient conditions was integrated rapidly leading to high and selective Sc recovery. A flow diagram of the developed leaching process in industrial scale was proposed based on continuous operation.
Chemistry and Materials Science, Metals, Alloys and Metallurgy
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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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