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pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud

This study analyzes the leaching behavior of elements from red mud (bauxite residue) at pH values ranging from 2 to 13. The leaching characteristics of metals and contaminated anions in five red mud samples produced by Bayer and combined processes were analyzed using the batch leaching technique fol...

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Autores principales: Cui, Yulong, Chen, Jiannan, Zhang, Yibo, Peng, Daoping, Huang, Tao, Sun, Chunwei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6603915/
https://www.ncbi.nlm.nih.gov/pubmed/31185604
http://dx.doi.org/10.3390/ijerph16112046
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author Cui, Yulong
Chen, Jiannan
Zhang, Yibo
Peng, Daoping
Huang, Tao
Sun, Chunwei
author_facet Cui, Yulong
Chen, Jiannan
Zhang, Yibo
Peng, Daoping
Huang, Tao
Sun, Chunwei
author_sort Cui, Yulong
collection PubMed
description This study analyzes the leaching behavior of elements from red mud (bauxite residue) at pH values ranging from 2 to 13. The leaching characteristics of metals and contaminated anions in five red mud samples produced by Bayer and combined processes were analyzed using the batch leaching technique following the US Environmental Protection Agency (USEPA) Method 1313. In addition, the geochemical model of MINTEQ 3.1 was used to identify the leaching mechanisms of metals. The results showed that Ca, Mg, and Ba follow the cationic leaching pattern. Al, As, and Cr show an amphoteric leaching pattern. The leaching of Cl(−) is unaffected by the pH. The maximum leaching concentration of the proprietary elements occurs under extremely acidic conditions (pH = 2), except for As. The leaching concentration of F(−) reaches 1.4–27.0 mg/L in natural pH conditions (i.e., no acid or base addition). At the same pH level, the leaching concentrations of Pb, As, Cr, and Cu are generally higher from red mud produced by the combined process than that those of red mud from the Bayer process. The leaching concentration of these elements is not strongly related to the total elemental concentration in the red mud. Geochemical modeling analysis indicates that the leaching of metal elements, including Al, Ca, Fe, Cr, Cu, Pb, Mg, Ba, and Mn, in red mud are controlled by solubility. The leaching of these elements depended on the dissolution/precipitation of their (hydr)oxides, carbonate, or sulfate solids.
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spelling pubmed-66039152019-07-17 pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud Cui, Yulong Chen, Jiannan Zhang, Yibo Peng, Daoping Huang, Tao Sun, Chunwei Int J Environ Res Public Health Article This study analyzes the leaching behavior of elements from red mud (bauxite residue) at pH values ranging from 2 to 13. The leaching characteristics of metals and contaminated anions in five red mud samples produced by Bayer and combined processes were analyzed using the batch leaching technique following the US Environmental Protection Agency (USEPA) Method 1313. In addition, the geochemical model of MINTEQ 3.1 was used to identify the leaching mechanisms of metals. The results showed that Ca, Mg, and Ba follow the cationic leaching pattern. Al, As, and Cr show an amphoteric leaching pattern. The leaching of Cl(−) is unaffected by the pH. The maximum leaching concentration of the proprietary elements occurs under extremely acidic conditions (pH = 2), except for As. The leaching concentration of F(−) reaches 1.4–27.0 mg/L in natural pH conditions (i.e., no acid or base addition). At the same pH level, the leaching concentrations of Pb, As, Cr, and Cu are generally higher from red mud produced by the combined process than that those of red mud from the Bayer process. The leaching concentration of these elements is not strongly related to the total elemental concentration in the red mud. Geochemical modeling analysis indicates that the leaching of metal elements, including Al, Ca, Fe, Cr, Cu, Pb, Mg, Ba, and Mn, in red mud are controlled by solubility. The leaching of these elements depended on the dissolution/precipitation of their (hydr)oxides, carbonate, or sulfate solids. MDPI 2019-06-10 2019-06 /pmc/articles/PMC6603915/ /pubmed/31185604 http://dx.doi.org/10.3390/ijerph16112046 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Cui, Yulong
Chen, Jiannan
Zhang, Yibo
Peng, Daoping
Huang, Tao
Sun, Chunwei
pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud
title pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud
title_full pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud
title_fullStr pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud
title_full_unstemmed pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud
title_short pH-Dependent Leaching Characteristics of Major and Toxic Elements from Red Mud
title_sort ph-dependent leaching characteristics of major and toxic elements from red mud
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6603915/
https://www.ncbi.nlm.nih.gov/pubmed/31185604
http://dx.doi.org/10.3390/ijerph16112046
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