Hedwig, Sebastian

Hedwig, Sebastian


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  • Publikation
    Nanofiltration-enhanced solvent extraction of scandium from TiO acid waste
    (American Chemical Society, 27.04.2022) Yagmurlu, Bengi; Huang, Danyu; von Arx, Oliver; Dittrich, Carsten; Constable, Edwin; Friedrich, Bernd; Hedwig, Sebastian; Lenz, Markus [in: ACS Sustainable Chemistry & Engineering]
    Scandium is a critical raw material with a technological potential to reduce transportation costs and CO2 emissions. However, global supply and market adoption are crucially impaired by the lack of high-grade Sc ores and recovery strategies. A tandem nanofiltration solvent extraction route is demonstrated to enable effective Sc recovery from real-world acid waste from the chloride TiO2 production route. The process involving several filtration stages, solvent extraction, and precipitation was optimized, ultimately producing >97% pure (NH4)3ScF6.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Publikation
    Recovery of scandium from acidic waste solutions by means of polymer inclusion membranes
    (Elsevier, 2022) Hedwig, Sebastian; Kraus, Manuel; Amrein, Meret; Stiehm, Johannes; Constable, Edwin C.; Lenz, Markus [in: Hydrometallurgy]
    Scandium is a raw material with properties that promise considerable potential for application in alloys to enable aviation fuel savings and as dopants for use in sustainable energy production using solid oxide fuel cells. Despite these attractive properties, scandium is rarely used due to its scarcity and unreliable supply. Therefore, new strategies for scandium recovery are of economic priority. In this study, polymer inclusion membranes (PIMs) consisting of PVDF-HFP, 2-NPOE and DEHPA, were optimised for selective scandium separation from real TiO2 production waste. With the optimised system, >60% of the scandium was recovered with high selectivity, resulting in scandium mole fraction at more than two orders of magnitude higher in the receiving phase than in the original waste. This suggests PIMs may be an effective way to recover scandium from bulk waste, thus easing the scarcity and insecurity that currently limit its bulk application.
    01A - Beitrag in wissenschaftlicher Zeitschrift