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Zhu F, Guo X, Gao H, Shi Y, Wang G, Du C, Jiang J, Wu Y, Hartley W, Xue S. Ecological restoration affects the dynamic response of alkaline minerals dissolution in bauxite residue. Sci Total Environ 2024; 912:169364. [PMID: 38104818 DOI: 10.1016/j.scitotenv.2023.169364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 11/19/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
Regulating alkalinity is the key process to eliminating environmental risk and implementing sustainable management of bauxite residue. Nevertheless, continuous release of free alkali from the solid phase (mainly sodalite and cancrinite) is a major challenge for long-term stability of alkalinity in amended bauxite residue. In order to understand the dissolution behavior of sodalite and cancrinite, their dissolution kinetics under simulated pH conditions of 8, 9 and 10 were investigated. Additionally, PHREEQC software and shrinking core model (SCM) were employed to analyze the release pattern of saline ions. The results revealed that the ratio of Na/Si and Na/Al values exhibited greater stability in sodalite than in cancrinite. The dissolution of elemental Na, Si, and Al in sodalite and cancrinite was matched with non-chemometric characteristics. The kinetic calculations by the shrinking core model (SCM) suggested that both sodalite and cancrinite exhibited slow dissolution kinetics, and their dissolution processes belong to internal diffusion control and external diffusion control, respectively. pH controlled the dissolution kinetic rates of sodalite and cancrinite mainly by changing their coupled dissolution-precipitation processes. More importantly, these findings can predict the change of alkaline components accurately, thus facilitating the implementation of efficient alkalinity regulation strategies for the ecological restoration of bauxite residue disposal areas.
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Affiliation(s)
- Feng Zhu
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Xuyao Guo
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Hui Gao
- Chinalco Mining Co, Ltd, Zhengzhou 450041, China
| | - Yafei Shi
- Chinalco Mining Co, Ltd, Zhengzhou 450041, China
| | | | - Chenxia Du
- Chinalco Mining Co, Ltd, Zhengzhou 450041, China
| | - Jun Jiang
- School of Metallurgy and Environment, Central South University, Changsha 410083, China.
| | - Yujun Wu
- School of Metallurgy and Environment, Central South University, Changsha 410083, China; College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
| | - William Hartley
- Royal Agricultural University, Gloucestershire, United Kingdom
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
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