Evaluation of Main Factors for Improvement of the Scandium Leaching Process from Russian Bauxite Residue (Red Mud) in Carbonate Media

Alexander V Boyarintsev; Htet Ye Aung; Sergei I Stepanov; Andrei A Shoustikov; Pavel I Ivanov; Vladimir G Giganov

doi:10.1021/acsomega.1c04580

Evaluation of Main Factors for Improvement of the Scandium Leaching Process from Russian Bauxite Residue (Red Mud) in Carbonate Media

ACS Omega. 2021 Dec 27;7(1):259-273. doi: 10.1021/acsomega.1c04580. eCollection 2022 Jan 11.

Authors

Alexander V Boyarintsev¹, Htet Ye Aung¹, Sergei I Stepanov¹, Andrei A Shoustikov¹, Pavel I Ivanov², Vladimir G Giganov³

Affiliations

¹ Department of Technology of Rare Elements and Nanomaterials based on them, Mendeleev University of Chemical Technology, 9 Miusskaya square, 125047 Moscow, Russia.
² D.I. Mendeleev Center for Collective Use of Scientific equipment, Mendeleev University of Chemical Technology, 9 Miusskaya square, 125047 Moscow, Russia.
³ State Research Institute of Non-ferrous Metals, 13/1 Academician Korolev street, 129515 Moscow, Russia.

Abstract

The carbonate leaching of scandium from the landfilled bauxite residue (red mud) of the Bogoslovsky Aluminum Plant (Russia) and samples of red mud (RM) after alkaline pretreatment has been investigated. The results of kinetic studies allowing to compare and evaluate the effectiveness of different conditions and intensification factors in the process of scandium leaching from RM in carbonate/bicarbonate media are presented. It was determined that for 2.0 mol L^-1 Na₂CO₃ leaching solution ultrasonic treatment under gas (CO₂) carbonation conditions in the pH range of 9.5-10.0 allows reducing the scandium leaching time by two times and reaching 40-45% scandium extraction. Leaching of RM in carbonate/bicarbonate media is accompanied by secondary processes (adsorption, hydrolysis, and coprecipitation) leading to a decrease in scandium extraction. The obtained results allow improving understanding of scandium chemical behavior in complex aqueous carbonate/bicarbonate systems and can be used for the optimization of the alternative carbonate process for scandium extraction from RM.