Article
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Preserved in Portico This version is not peer-reviewed
Novel Method of Bauxite Treatment Using Electroreductive Bayer Process
Version 1
: Received: 19 July 2023 / Approved: 19 July 2023 / Online: 19 July 2023 (10:44:46 CEST)
A peer-reviewed article of this Preprint also exists.
Shoppert, A.; Valeev, D.; Loginova, I. Novel Method of Bauxite Treatment Using Electroreductive Bayer Process. Metals 2023, 13, 1502. Shoppert, A.; Valeev, D.; Loginova, I. Novel Method of Bauxite Treatment Using Electroreductive Bayer Process. Metals 2023, 13, 1502.
Abstract
Reductive leaching in the Bayer cycle using of iron (2+) allows Al extraction to be significantly increased by magnetization of Al-goethite and Al-hematite. However, the use of expensive iron (2+) salts or iron powder as a source of iron (2+) leads to a significant increase in production costs. In this work, the feasibility of a new method, the reductive leaching of bauxite using an electrolysis process, was investigated. Reduction of iron minerals of boehmitic bauxite in both Bayer solution and purely alkaline solutions were carried out. Experiments were performed using a plate cathode and a bauxite suspension in alkaline solution, as well as using a bulk cathode with a stainless-steel mesh at the bottom of the cell as the current supply. During the electrolysis process, the potential of the cathode relative to the reference electrode was measured as a function of current at different concentrations of solid (100-300 g L–1) and suspension temperatures (95-120 °C). It is shown that the current efficiency using suspension and plate cathode with the predominant deposition of Fe doesn’t exceed 50% even with the addition of magnetite to increase the contact of solid phase with the current supply. With the use of a bulk cathode, the reduction of iron minerals leads predominantly to the formation of magnetite with the efficiency of using electric current more than 80%. As a result of preliminary desilication and electroreduction it is possible to extract more than 97% of Al from bauxite, and to increase the iron content in the bauxite residue to 57-58%.
Keywords
hematite electroreduction; boehmitic bauxite; Al extraction; reductive leaching; red mud; bauxite residue; magnetite; waste utilization
Subject
Chemistry and Materials Science, Chemical Engineering
Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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