Metal Recovery and Exploitation of Lignite Ashes by Combined Physicochemical and Biotechnological Approaches

Abstract

Ashes from lignite combustion for power generation contain strategic metals, metalloids and rare earth elements and may thus be a potential source of industrially demanded metals. The presented project focuses on the assessment and exploitation of this potential raw material. Lignite ash assessment showed that largest ash amounts for potential exploitation are available in the Lusatia district, Saxony. Mechanical ash pre-treatment in principle provided enriched fractions by different methods but still suffered from low yields of enriched fractions. Thermal ash processing showed multiple significant phase changes compared to original ash. Subsequent chemical leaching using HClaq resulted in high metal extraction. Alternatively, bioleaching was applied using acidophilic Fe (II) and S-oxidizing or Fe (III)-reducing microorganisms (MO) as well as heterotrophic MO. The results indicated likewise high and partly specific metal mobilizations. Industrial ash exploitation was accomplished by direct reaction with acids resulting in Al-Fe-solutions which potentially can be applied in water treatment.

Technische Chemie 2016

“…33) Me-chanistische Einblicke in die elektrochemische CO 2 -Reduktion an Zinnelektroden lieferte die Arbeitsgruppe von Andrew Bocarsly mit In-situ-ATR-IR-Spektroskopie. 34 44) Diese Rückgewinnung wird aus der Gasphase, 48) durch hybride, elementspezifische Prozesse und Membranverfahren aus Laugenlösungen, 49) über Flüssig-Flüssig-Extraktion 50) oder die Kombination von physikochemischen und biotechnischen Prozessen 51,52) 59) Konzepte der instationären 60) und erzwungen periodischen Betriebsweise 61) werden nach vielen Jahren wieder diskutiert und dazu genutzt, Reaktorleistungen robust zu erhöhen.…”