Recovery of Scandium by Crystallization Techniques

Peters, Edward Michael
Kaya, Serap
Dittrich, Carsten
Forsberg, Kerstin
Bauxite residues, i.e., red mud, can be processed to recover various valuable end products, while reducing the environmental impact of the waste. Scandium is one of the valuable elements in bauxite residues. It is possible to extract and enrich scandium from red mud by leaching and solvent extraction. Scandium can then be recovered from the pregnant strip liquor by crystallization. Different crystallization techniques can be used to generate the supersaturation required for scandium to crystallize out as a salt. In the present study, the crystallization of an ammonium scandium fluoride phase by cooling and antisolvent crystallization techniques is presented. Cooling crystallization gave a low yield of ammonium scandium hexafluoride, (NH4)(3)ScF6, below 50% at the lowest temperature of 1 A degrees C investigated. Antisolvent crystallization using ethanol gave almost complete recovery with precipitation efficiency greater than 98% for an ethanol-to-strip liquor volumetric ratio of 0.8. Solubility data of (NH4)(3)ScF6 under different temperatures and in different ethanol-strip liquor mixtures is herein presented. The product obtained by antisolvent crystallization had very minute crystals (< 2 A mu m) due to the high supersaturation generated upon adding ethanol to the strip liquor, while it was easier to obtain larger crystals by cooling crystallization. Fe and Ti impurities were detected in the solid product, and an insight into the mechanism of impurity uptake is discussed.


Preparation of antimicrobial films from agricultural biomass
Seber, Ayşe Gizem; Bakır, Ufuk; Department of Biotechnology (2010)
Mainly used food packaging materials are petro-chemical based polymers which present environmental problems since they are not biodegradable and ecologically sustainable. In this study, biodegradable biofilms are produced from xylan, extracted from cotton stalk which is an agricultural biowaste without nutritional value. Antimicrobial property was given to the biofilms with either titanium dioxide sol-gel coatings or titanium dioxide powder addition into the biofilm forming solutions. The antimicrobial acti...
Production of hemicellulose-based biodegradable films from agricultural wastes
Bahcegul, E.; Özkan, Necati; Bakir, U. (2009-09-01)
Owing to the increasing environmental awareness and restrictions together with the depletion of fossil-based resources, production of biodegradable films receives increasing attention to substitute at least a part of the largely consumed conventional synthetic plastics. Despite there are a variety of polymers that are used for biodegradable plastic production these alternatives are either more expensive compared to their non-biodegradable petroleum-based counterparts or obtained from sources such as corn or...
Harb, Rayaan; Bayramoğlu, Tuba Hande; Department of Environmental Engineering (2023-1-20)
Recently, the implementation of next-generation biological nutrient removal techniques aimed at recycling nutrients such as nitrogen and phosphorus while generating energy, producing value-added products and mitigating greenhouse gas emissions, in wastewater treatment plants is being emphasized. In this regard, investigating the development and applicability of a DAMO-Anammox co-culture and a novel DAMO-Anammox-Microalgae sequential treatment unit in the treatment of anaerobic digester (AD) effluent was the...
Treatability of chromite ore processing waste by leaching
Ünlü, Kahraman (SAGE Publications, 2001-06-01)
Developing treatment and disposal strategies and health-based clean-up standards for chromium containing wastes continues to be an important environmental regulatory issue because of the opposing solubility and toxicity characteristics of chromium species under diverse environmental conditions. In this study, leaching characteristics of total Cr and Cr(VI) were investigated using laboratory column studies. The data obtained from the experimental studies were analysed to assess the treatability of chromite o...
Construction of amperometric biosensor modified with conducting polymer/carbon dots for the analysis of catechol
Yasa, Mustafa; Deniz, Aybuke; Forough, Mehrdad; Yildirim, Erol; Persil Çetinkol, Özgül; Udum, Yasemin Arslan; Toppare, Levent Kamil (Wiley, 2020-10-21)
Phenolic compounds used in food industries and pesticide industry, are environmentally toxic and pollute the rivers and ground water. For that reason, detection of phenolic compounds such as catechol by using simple, efficient and cost‐effective devices have been becoming increasingly popular. In this study, a suitable and a novel matrix was composed using a novel conjugated polymer, namely poly[1‐(5‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b']dithiophen‐2‐yl)furan‐2‐yl)‐5‐(2‐ethylhexyl)‐3‐(fu...
Citation Formats
E. M. Peters, S. Kaya, C. Dittrich, and K. Forsberg, “Recovery of Scandium by Crystallization Techniques,” JOURNAL OF SUSTAINABLE METALLURGY, pp. 48–56, 2019, Accessed: 00, 2020. [Online]. Available: