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ArticleName Extraction of scandium from sulphuric acid-based red mud leach liquors
DOI 10.17580/tsm.2022.04.04
ArticleAuthor Abdurakhmonov O. E., Semenov S. A., Sokolova Yu. V.

D. Mendeleev University of Chemical Technology of Russia, Moscow, Russia:

O. E. Abdurakhmonov, Postgraduate Student, Department Nanomaterials of and Nanotechnology, e-mail: odilzhon.abdurakhmо


MIREA — Russian Technological University, Lomonosov Institute of Fine Chemical Technologies, Moscow, Russia:
S. A. Semenov, Professor, Bolshakov Department of Chemistry and Technology of Rare Elements, Doctor of Chemical Sciences


JSC VNIICHT, Leading Research of Cemical Technology, Moscow, Russia:
Yu. V. Sokolova, Leading Researcher Fellow, Laboratory of Technogenic Waste Processing, Doctor of Technical Sciences, Associate Professor


Equimolar mixtures of di-2-ethylhexylphosphoric acid (D2EHPA) with trin-butylphosphate (TBP) or trioctylamine (TOA) in kerosene were used for extracting scandium from sulphuric acid-based red mud leach liquor. The results showed that when using a D2EHPA-TOA mixture, the overall extraction of scandium (ЕSc) tends to rise from 37 to 68% as the concentration of sulphuric acid rises. At the same time, the extraction of concomitant elements tends to decrease and remains way below the Е Sc . When using a D2EHPATBP mixture, the rising acidity of the solution does not lead to any significant increase in scandium extraction so that the latter remains quite high (i.e. 82–85%) while the extraction of the concomitant elements is significantly lower. A five-stage countercurrent extraction process was performed using a mixture of 0.1 mol/L D2EHPA and 0.1 mol/L TBP with 2 mol/L sulphuric acid to recover scandium from the liquor with minimized amounts of concomitant metals. The results showed that a 96.8% of scandium can be recovered after a three-stage countercurrent extraction process with 97% aluminium, 95% iron, 87% titanium and 54% zirconium removed from the liquor. A 4.7 mol/L sulphuric acid solution with an organic to aqueous ratio of 1:1 was used to wash the organic phase after a three-stage extraction process. For reextraction, a solution containing 2.5% NaOH and 6.5% Na2CO3 was used at a 2:1 aqueous to organic phase ratio. The solution was filtered to separate the solid phase. The precipitate was washed and dried and a primary 3.42% concentrate was obtained. Based on the obtained data, the authors describe a scandium extraction process using sulphuric acid-based red mud leach liquor. The new scandium concentration by extraction process parameters were tested on an enlarged scale at the Intermix MET site. A 100 g experimental batch of primary scandium concentrate containing, %: 2.2 Sc; 21.8 Тi; 4.3 Na; 0.6 Al; 1.7 Fe; 5.0 Zr; 0.0056 Y, was obtained from a 260-litre red mud leach liquor. For this, a cascade of five centrifugal extractors was used at the extractant saturation stage. An 8-litre mixture of 0.1 mol/L D2EHPA and 0.1 mol/L TBP in Exxsol D100 was used. The organic phase was in recycle, and due to that its saturation was 340 mg of scandium per litre of extractant.

keywords Red mud, scandium, extraction, reextraction, di-2-ethylhexyl phosphoric acid (D2EHPA), tri-n-butyl phosphate (TBP), trioctylamine (TOA)

1. U.S. Geological Survey, Mineral Commodity Summaries. 2022. p. 146, 147.
2. Weiwei W., Pranolo Y., Cheng C. Y. Metallurgical processes for scandium recovery from various resources: A review. Hydrometallurgy. 2011. Vol. 108, Iss. 1–2. pp. 100–108.
3. Liu Z. , Li H. Metallurgical process for valuable elements recovery from red mud — A review. Hydrometallurgy. 2015. Vol. 155. pp. 29–43.
4. Pulfold I. D., Hargreaves J. S. J., Durisova J. et al. Carbonised red mud — A new water treatment product made from a waste material. Journal of Environmental Management. 2012. Vol. 100. pp. 59–64.
5. Sokolova Yu. V., Koryakov V. B., Per'kov P. G. Extraction concentration of scandium(III) with production of fluoride concentrate. Russian Journal of Non-Ferrous Metals. 2004. Vol. 45, No. 8. pp. 18–24.
6. Koryakov V. B., Sokolova Yu. V. Modeling and optimization of the parameters of scandium extraction and reextraction together with production of rough fluoride concentrate. Russian Journal of Non-Ferrous Metals. 2004. Vol. 45, No. 3. pp. 18–25.
7. Abdurakhmonov O., Semenov S., Sokolova Yu. Recovery of scandium from red muds by extraction. Extraction and Membrane Separation of Substances: Proceedings of the international conference marking the 90th birthday of the academician B. A. Purin. Moscow : RKhTU im. D. I. Mendeleeva, 2018. pp. 36–38.
8. Zhang W., Zhang T. A., Lv G., Zhou W. et al. Extraction separation of Sc(III) and Fe(III) from a strongly acidic and highly concentrated ferric solution by D2EHPA/TBP. JOM. 2018. Vol. 70, Iss. 12. pp. 2837–2845.
9. Das S., Behera S., Murmu B. M., Mohapatra R. K. et al. Extraction ofs candium(III) from acidic solutions using organo-phosphoric acid reagents: A comparative study. Separation and Purification Technology. 2018. Vol. 202. pp. 248–258.
10. Li G., Ye Q., Deng B., Luo J. et al. Extraction of scandium from scandiumrich material derived from bauxite ore residues. Hydrometallurgy. 2018. Vol. 176. pp. 62–68.
11. Stepanov S., Pei K., Boyarintsev A., Giganov V. et al. Scandium extraction from sulphuric acid solutions by mixtures of D2EHPA and MTAA sulfate in toluene. Theoretical Foundations of Chemical Engineering. 2017. Vol. 51, Iss. 5. pp. 846–849.
12. Sokolova Yu. V., Bogatyreva E. V. Method of extracting scandium from red mud from alumina production. Patent RF, No. 2581327. Applied: 19.01.2015. Published: 20.04.2016.
13. Hirashima Y., Mugita M., Shiokawa J. Synergistic extraction of lanthanoids with di(2-ethylhexyl)phosphoric acid and some reagents. Journal of Inorganic and Nuclear Chemistry. 1976. Vol. 38. pp. 1199–1202.
14. Moskva V. V. Hydrogen bonding in organic chemistry. Sorovskiy obrazovatelnyi zhurnal. 1999. No. 2. pp. 58–64.
15. Korshunov B. G., Reznik A. M., Semenov S. A. Scandium. Moscow : Metallurgiya, 1987. 184 p.
16. Akimova I. D., Chumakova G. M., Molchanova T. V., Golovko V. V. Scandium concentrate production by liquid extraction from the hydrolyzed sulphuric acid which is a by-product of titanium dioxide manufacturing. Tsvetnye Metally. 2017. No. 3. pp. 63–68. DOI: 10.17580/tsm.2017.03.10.

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