Alkali Recovery of Bauxite Residue by Calcification
Bauxite residue (red mud) generated during alumina production is a highly alkaline solid waste. The red mud is mainly stored on land, but it can cause harm to the surrounding environment and human health. The transformation of red mud into soil is a feasible method for the large-scale disposal of re...
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| Format: | Article |
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MDPI AG
2022-05-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/12/5/636 |
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| author | Wanzhang Yang Wenhui Ma Pengfei Li Zhanwei Liu Hengwei Yan |
| author_facet | Wanzhang Yang Wenhui Ma Pengfei Li Zhanwei Liu Hengwei Yan |
| author_sort | Wanzhang Yang |
| collection | DOAJ |
| description | Bauxite residue (red mud) generated during alumina production is a highly alkaline solid waste. The red mud is mainly stored on land, but it can cause harm to the surrounding environment and human health. The transformation of red mud into soil is a feasible method for the large-scale disposal of red mud, but alkali removal is the key process that controls the transformation of red mud into soil. In this study, the calcification dealkalization of red mud with a small particle size was carried out below 100 °C. The results show that the sodium in red mud is predominately distributed in small particles, mainly because the lattice alkali and alkali present between the crystals are exposed to the surface of red mud particles by ball milling. The dealkalization process was controlled by the internal diffusion of the shrinking-core model (SCM), and the apparent activation energy was 23.55 kJ/mol. The dealkalization rate and the Na<sub>2</sub>O content of dealkalized red mud reached 92.44% and 0.61%, respectively. The dealkalization rate increased with increasing reaction time, reactant concentration, and leaching temperature, and this result was consistent with the results of the kinetic study. In addition, calcification enhances the flocculation of particles, so the filtration performance of red mud improved. |
| first_indexed | 2024-03-10T03:20:54Z |
| format | Article |
| id | doaj.art-37ee1b7d36b7447d8effe996cf0def00 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T03:20:54Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-37ee1b7d36b7447d8effe996cf0def002023-11-23T12:19:48ZengMDPI AGMinerals2075-163X2022-05-0112563610.3390/min12050636Alkali Recovery of Bauxite Residue by CalcificationWanzhang Yang0Wenhui Ma1Pengfei Li2Zhanwei Liu3Hengwei Yan4State Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming University of Science and Technology, Kunming 650093, ChinaState Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming University of Science and Technology, Kunming 650093, ChinaState Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming University of Science and Technology, Kunming 650093, ChinaState Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming University of Science and Technology, Kunming 650093, ChinaState Key Laboratory of Complex Nonferrous Metal Resources Cleaning Utilization, Kunming University of Science and Technology, Kunming 650093, ChinaBauxite residue (red mud) generated during alumina production is a highly alkaline solid waste. The red mud is mainly stored on land, but it can cause harm to the surrounding environment and human health. The transformation of red mud into soil is a feasible method for the large-scale disposal of red mud, but alkali removal is the key process that controls the transformation of red mud into soil. In this study, the calcification dealkalization of red mud with a small particle size was carried out below 100 °C. The results show that the sodium in red mud is predominately distributed in small particles, mainly because the lattice alkali and alkali present between the crystals are exposed to the surface of red mud particles by ball milling. The dealkalization process was controlled by the internal diffusion of the shrinking-core model (SCM), and the apparent activation energy was 23.55 kJ/mol. The dealkalization rate and the Na<sub>2</sub>O content of dealkalized red mud reached 92.44% and 0.61%, respectively. The dealkalization rate increased with increasing reaction time, reactant concentration, and leaching temperature, and this result was consistent with the results of the kinetic study. In addition, calcification enhances the flocculation of particles, so the filtration performance of red mud improved.https://www.mdpi.com/2075-163X/12/5/636Bayer red muddealkalizationcalcificationleaching kinetic |
| spellingShingle | Wanzhang Yang Wenhui Ma Pengfei Li Zhanwei Liu Hengwei Yan Alkali Recovery of Bauxite Residue by Calcification Minerals Bayer red mud dealkalization calcification leaching kinetic |
| title | Alkali Recovery of Bauxite Residue by Calcification |
| title_full | Alkali Recovery of Bauxite Residue by Calcification |
| title_fullStr | Alkali Recovery of Bauxite Residue by Calcification |
| title_full_unstemmed | Alkali Recovery of Bauxite Residue by Calcification |
| title_short | Alkali Recovery of Bauxite Residue by Calcification |
| title_sort | alkali recovery of bauxite residue by calcification |
| topic | Bayer red mud dealkalization calcification leaching kinetic |
| url | https://www.mdpi.com/2075-163X/12/5/636 |
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